Pleiades long tailed pair tube only microphone pre preamplifier with No resistors or capacitors

This started at about 1999.


The microphone drives the primary of the input transformer. The secondary is connected to the grids of a balanced configuration of UCC85.


The anodes are connected to the primary of the output transformer. The secondary is the balanced output of the very quiet pre preamplifier.


The cathodes are connected together with one side of a 270 ohms resistor , the other side to ground.


This was a stereo 2 channel amp so two UCC85 were used. Heaters in series were driven by 4x12V lead acid batteries in a separate sealed cast aluminum box.


So 48V were also connected to the center tap of the output transformers.


48V is also convenient since if connected to the center tap of the primary of the input transformer, phantom power is ready.


The amplifier was built in a cast aluminum box from Canford. Tubes on top as well as as the 4 Sowter transformers. 1:7 was used for input and 1:1 for output either 10K:10K or 600 to 600.


The amp was used with AKG 12A Nuvistor microphones as Blumlein Pair.


The mics were near the drums. The mics were on cardiod looking at the organ past one step so that some direct sound could be picked up from the drums. All instruments including drums, self amplified guitar, bass guitar and PCL86 amplified organ with Pleiades Leslie hung from the ceiling so that the open back speaker could freely revolve sounded very nice. Out out of the amp was connected directly to the input of Philips CDR870. Some more gain could have been useful as the amp could not fully modulate the recorder. This was useful as there was no clipping involved in the jam no matter what, or was this the compression effect of tubes with grid bias self adjusted when peaks were trying to charge grids negatively  due to diode rectification effect?


The interesting thing about this amp that there is no return circuit for grids.. By listening and watching now at VU meters it seems the amplifier was self compressing at loud signals since the grids were free to keep the potential convenient for them.


There was also an 1K resistor in series with battery plate supply inside the amp,


Now the amp has been changed to 2 ECC82 parallel heaters and O ohms cathode resistor, and 12V battery supply. Interesting is that the intensity of light in the room adjusts gain of the amp possibly due to photoelectric effect of grids?


The amp may be reconverted  to UCC85.

Learn how to compose music in a few minutes

Step 1
Choose a scale:
We will choose the simplest one but the same will apply with any scale.
Let's choose A minor scale.
That's is A B C D E F G A.

Step 2
Using the simple 1 3 5 rule, this defines 7 chords that can be used.


ACE
BDF
CEG
DFA
EGB
FAC
GBD


Note some are minor and some major. This is selected automatically by nature so you do not have to remember anything.

Step 3
Start playing

Apart from rhythm music consists of Bass, Harmony, Melody.


We can begin by Bass A and harmony ACE, then bass C, right hand CEG.


Note ACE, CEG can be anywhere in the keyboard. So inversions apply.


Melody can be any note of the scale in any imaginative way.


A key element of music is repetition.


Experiment having your ear brain as judge.


Avoid consecutive 5ths which sound bad.


For example ACE to GBD sounds much better, as ACE to GBE to FACE.


This introduces us to new chords having other code than 135.


For example GBE is written as G6.


With a 6th a third is taken so G6 is played GBE.


With a 7th or a 9th the 3rd and 5th is taken too and the 7ths and 9ths sound better when they are prepared or

How to wind a toroidal core by hand

The trick is to use a thin and long peace of wood with some material removed with a knife or thin file on top a bottom.


The long wire is wound on this peace of wood several turns.


Every turn on the toroid is made by passing this peace of wood through the toroid to make great Pleiades microphone filters or input or mixing transformers.

Amorphous Transformer Cores for microphones and MC cartridges

Amorphous is similar word to nano crystalline or met glass, metal glass signal transformer core.


Pleiades microphone transformers use nanoperm tape would toroidal cores made by Magnetec which have an extreme magnetic permeability. This reduces number of turns for given inductance, increasing bandwidth and decreasing noise as wire resistance is very low.

Ribbon microphone random corrugated.

A ribbon microphone can be corrugated in an asymmetrical random sort of way to avoid standing modes of vibration.


This is done by folding many times by hand the sandwich paper that protects the ribbon before or after cutting the ribbon strip.

Microphones in series or parallel

Connected an MD421HL in series with 515SB. The resultant 400ohms was connected to Pleiades V5. Great sound, MD on vocals, 515 on acoustic guitar. Proximity effect is further compensated as effective mic Zout is increased. In fact many mics could be connected in series, in a Christmass tree lamp way and the proximity effect be automatically compensated. A live band could be recorded this way indoors or outdoors with a great sound with no reflection components as the mics would be really close to the instruments and a great signal to noise ratio for the same reason.


Connected MD421 in parallel with Shure 515SB. Great sound, more bass, less treble. This can be explained by the lower total Zout, this time 100Ohms. Cutoff proximity compensating frequency due to Zout and the 47uH input inductance of V5 is now halved, ie one octave lower.

Adding (Mixing) many Microphone signals

Can many microphone signals be added together by series parallel connection of the microphones themselves to keep resultant mic impedance at 200 Ohms.


It would nice doing away completely with mixing console or even hybrid adding transformers.


It would be nice recording a live band this way.

Electro-Voice Microphones

it can be found on the web that Dolly Parton and Elvis were using the Electro Voice RE15 moving coil microphone in the studio.


There is also an excellent demo on harmonica using the RE15 on YouTube. Amazing sound, fabulous midrange.

Pleiades V5 prototype finished? with circuit discription

2 stage EF183 electron tube microphone battery field pre preamplifier with proximity compensating input transformer




It took 40 years and a few days.


Balanced input
Microphone proximity compensated input
Unbalanced low Z output or balanced with an output transformer
Uses 2 3.7V Li Ion batteries


Circuit description:


Energy feed first:
 The 2 Li Ion batteries and the fuse are in series and the 7.4V are connected to the series heaters. Each EF183 tube feeds from 3.7V instead of 6.3V. This keeps electron emission congestion low so that the tiniest signal from the microphone can be amplified with least noise.


Advantages, portability, no transformers, no diodes, no chokes, no electrolytic capacitors, and above all no countless sources of hum when we want to extract the subtlest nuances of voice.


The negative battery supply is connected to the XLR shield connector and everything negative is star connected there including of course pin 1 (see excellent Jensen transformer papers).


When microphone is connected electrons move back and forth in a balanced way in twisted cables 2 and 3, feeding through the XLR the primary (orange winding) of the microphone input transformer. Common mode signals ie not moving back and forth but in the same direction such as RF and line hum travel along the orange wires and collide with themselves so there are extinguished.


The input transformer is completely symmetric electrical and physically allowing a fully balanced operation with no shield needed. The toroidal core is a Magnetec nanoperm noncrystalline core of extremely high magnetic permeability.


As each electron moves back and forth at the microphone music signal it repels the next electron on the orange twisted cable and so forth so all electrons get to dance!.


Inside the orange transformer coil currents move clockwise anticlockwise dancing to the music.


The core is Magnetec 060, Primary winding is 35 turns and secondary 350 turns.


Jealous electrons see all this spinning in the primary winding and they cant help but spin too inside the noncrystalline tape wound core. Jealous electrons at the secondary winding dance too spinning in a waltz sort of way but since there are 350 turns the corresponding voltage is 10 times.


One side of the secondary is connected to star ground the other to the coupling capacitor to eliminate direct currents to and from tube grid on the other side. It is the dance back and forth component that matters.


When we connect the batteries we have a closed circuit of electrons  moving fast through the heaters. Fast electrons collide with atoms and heater atoms move back and forth at greater speeds ie the temperature is greater. Collisions with surrounding cathode inside the evacuated EF183 tube make electrons move faster. Some of them as temperature ie speed is increasing can escape into empty space nearby inside glass.Because of them surrounding space near grid becomes negative repelling further electrons or cathode is positive wrt grid due to lack of them. This is one reason why we do not heat up with 6.3V as there is no point in having billions of electrons move in all sorts of directions when the tiny music signal arriving at the grid has relatively few romantically dancing electrons.


A 4.7Megohm resistor is connected to grid and its other side to positive anode. Its purpose is neutralising the negative potential that as explained exists at the grid so that we can have anode current influenced by the dancing electrons at the grid ie amplification.


To be continued. 

A great way to mic up drums...

Is with 2 mics, one above drum set, the other as close or inside the bass drum.


Electro voice RE microphones do the trick.


See an amazing clip on YouTube with sm57 and RE11. How did he mic up the drums?


Also one showing Bob Clearmiuntain.


Photos of Beatles showing a ribbon mic, Coles 4038. Also on various books how the technicians at Abbey Road managed to persuade management to allow the, to close mic the bass drum.


Saw a veteran drummer once micing g a whole drum set live with just one Electro Voice mic.


Amazing.

Shure Unidyne iii

Barack Obama and all US Presidents since 1965 use the Shure Unidyne iii or SM57 microphone  for speech.


It is also used by Brian Wilson on Pet Sounds as well as Sinatra, Bono U2 (SM58), David Bowie for recording vocals in the studio.

Pleiades V5 prototype under construction

Prototype under construction Pleiades V5 microphone pre pre amplifier with 2 EF183 electron types positive biased for freeing electrons at 7.5V 

Schematic of Pleiades V5, 2 stage EF183 electron tube with positive bias, microphone pre preamplifier with proximity compensating transformer and instantaneous clipping rounding waveform capacitor

Figured Bass Orchestra

Could an orchestra be made where all musicians have perfect pitch and play without reading notes, by understanding figured bass?


It would be like  the most beautiful instrument playing on its own.


They could hear something and play it or compose themselves in real time thinking fighter bass.

Pleiades Magnetec Neutrik iPad microphone setup

It would be great to make a Pleiades microphone pre preamplifier as follows:


Everything inside Neutrik XLR modules:


Inside a Magnetec 073 nanocrystalinne core,  few primary turns for bass proximity compensation.


Capacitor coupling of secondary to a K177 JFET.


Everything inside the Neutrik modules and power and drain resistor supplied by the iPad headphone mic connector.


This would provide at the same time: proximity compensation for next to mouth mic work, make up gain, extremely low noise, ie great signal to noise ratio, portability, crystal clear sound.

Maximum Information Extraction

If a Pleiades microphone transformer with Magnetec 073 core, capacitor couples the grid of a positive biased EF183 at 5V anode voltage and less than 3V? Heater voltage, a microscope equivalent is created as at such small electron speeds the electron tube is extremely quiet.


Maximum information extraction.


Makes wonders on dynamic and ribbon microphones.

10k to 600 ohm audio transformer microphone step-up step-down impedance hi-z

Just tried this step up transformer bought from TechnoFix on eBay, TL019-R 1438.


Sounded amazing connected to the Pleiades V4 pre preamplifier.


The coupling capacitor to grid on V4 is 220nF. It is very important to capacitor couple to an electron tube grid so that the valve's grid is free. (Not made by force to assume a potential).


The primary inductance of the transformer is 100mH at 1028Hz and 165mH at 97Hz making wonders at compensating the proximity effect of the MD421HL and SM58 (made in Mexico) used. Mic mouth distance approximately 1 in.


Connecting the transformer to the grid of the EF183 made the high frequency response high but not high enough to sound over detailed and unnatural. It seems therefore to compensate the high frequency proximity effect due to the obstacle effect too.


Secondary inductance is 7H making a 1:8.5 step up.


Bravo to the designers, a giant killer!

Who said that microphones should have a flat frequency response?

Perhaps nobody did.


Truth is that what counts is not flat response from mic to loudspeaker but...


Flat frequency response from the vocal cords of the singer to the brain of the listener (explained on the Hollywood paper referred to in older posts).


Apart from this are proximity boost effects at low and high frequencies which must be compensated.


All these effects may explain why a "lesser" mic or input transformer can be a giant killer.


The record industry uses Pultec filters to this end but why not producing a mic where the sound is already there?


Be prepared that frequencies below 1KHz for example must be reduced if a directional microphone is used at next to mouth distance. Similar apparently crazy things must be done at the high end of the spectrum
More on the following posts....

How does a Pleiades filter work?

A Pleiades filter is just an inductor in parallel with the signal.


By reducing the winding turns the cutoff frequency is increased and even closer mic source distances are possible. The same principle can be applied to a Pleiades transformer ie reducing primary turns thereby reducing primary inductance and increasing cuttoff frequency therefore making the mic focus at a smaller distance. Decreasing primary turns has the added advantage of automatically increasing the transformer turn ratio. So this iautomaticaly makes up gain. The core used to make the Pleiades inductor or transformer is an extremely high inductance index nanocrystalinne cores made by Magnetec. This makes possible Pleiades filters with very few number of turns. Example of a core is Magnetec Nanoperm 073.


A Pleiades filter can compensate for proximity effect even at a next to mouth mic distance minimising feedback at PA systems and virtualy eliminating pop and wind noise although its a good idea not to remove the microphone grill as it does much wind noise reducing work. After filtering the signal is so clear that one can hear the greyest detail from a voice. If high frequency cutoff is needed for reasons explained on other posts this can be done by a Pleiades high cut finger which consist of just one capacitor in parallel with signal.


A Pleiades transformer with its high impedance can drive the gate of a JFET or the grid of a vacuum tube trough a calling capacitor. On following posts Pleiades pre preamplifier are  described including an extremely low noise electron tube one powered by 5V only at the the anode (plate). This is achieved by large Megohm resistor from Anode to grid to free electrons.


Such Pleiades pre preamplifiers next to the output of the microphone transformer make dynamic or ribbon microphones so sensitive that play condenser microphones in their own game.


How does a Pleiades filter work?


The microphone output impedance is in series with the inductor and together form a potential divider.
The inductor impedance as usual increases with frequency and makes the microphone output increasing with frequency at 6dB per octave compensating the proximity effect. After the cutof frequency the impedance of the inductor becomes so high that there is no voltage drop at the mic and response contineous to be flat.


How does damping work?


At low frequencies the droping impedance of the inductor (which becomes just it's winding resistance at zero frequency) makes a large current flow through the coil (shorts circuits the coil at LF). This makes the coil behave like a loudspeker but moving in the oposite direction to the cause (sound wave, blast, pop etc) this is Lens  law in action being a represantation of concervatiin of energy for if this force were of the same direction as the cause we would have amplification for free, imposible.




This is the same principle as a brake in electric cars by short circuiting  the output of the motor when the car is running.



Another way to put it, it's kunitic energy converted to heat.



This creates a very effective pop and wind filter.
Wanted sound is  unaffected as at voice frequencies the impedance of the inductor (which increases with frequency) has become large as to no longer be a load on the voice coil, letting it free to move at the pristine quality of your voice.

Compensating for the 2 proximity effects on a Shure SM58

There are 2 proximity effects (when mic is close to mouth), one the increases bass  and the other that increases treble called the obstacle effect


Natural sound from vocal cords to brain of listener for a Mexico made  SM58 next to mouth were obtained as follows:


SM58 was shunt with 19.5mH !  i.e. low cut at 1.6KHz and 15nF shunt to the Pleiades V4 (EF183 pre preamp with 4 AA batteries) output to reduce treble boost, sibilants, saliva noise (sometimes desirable). Added advantage is the reduction of any hiss left and rounding waveform curves should instantaneous peak limiting  occurs at the electron tube, thereby preserving subjective volume due to natural harmonics produced while objectively limiting the signal.


Signal path used:


Voice - SM58 - Pleiades 1:7 input transformer, 19.5mH primary L - V4 (+ve bias from plate to grid) - 15nF across output - Realistic Disco mixer mic in - pad before headphones - Sennheiser HD560 - ears - brain

Pleiades Ribbon mic transformers

A great ribbon microphone transformer can be wound on an extremely high inductance index nanoperm tape wound core by Magnetec.


The very few turns needed would result in an excellent step up transformer with least noise figure.


Silver wire could be used for the 2 windings.

Pleiades Mixing Console

It would be great to make a passive mixing console with just summing transformers (hybrid transformers) made with Magnetec's nanocrystalinne tape wound toroidal cores.


The best way to add signals with minimum loss is with spliter transformers connected the other way round.


Signal 1 is connected to upper side of primary winding. Signal 2 is connected to lower side of primary, Center tap of primary is connected through canceling resistor to ground. Signal (1+2) is received from secondary in all its pristine glory.


This is how Hollywood did it and more information can be found in earlier euroelectron posts. Many signals can be combined to one.

Pleiades 2 stage EF183 battery microphone preamplifier with positive biasing resistor from anode to grid and Magnetec core Pleiades bass proximity compensating input transformer, (under construction)

2 li-ion 3.7V batteries will be used in series for series heaters (each tube heater deliberately at 3.7V, see older posts) and anode supply 7.4V.


Schematic and completed prototype of 1 stage EF183 battery pre preamplifier is given on following posts.


Pleiades public domain dedication

Pleiades 4 focus points, microphone proximity compensating and pop filter schematic with Magnetec cores and Neutrik modules

4 focus points. (optimum bass proximity compensated distances from sound source to microphone)


For 16 points use 4 cascaded Pleiades filters.


Pop blast filtering due to electromagnetic damping.


Passes phantom power as inductors are in parallel with signal.


Gentle 6dB per octave low cut filtering (1st order slope as filter consists of the mic's output impedance in series with the Pleiades filter's  inductance) for overall flat frequency response compensating for the increase of bass content when directional mics at used at close distance.


Relatively few turns needed due to the extremely high inductance index of nanocrystalinne Magnetec cores, Magnetec 073 tape wound nanoperm core or equivalent. Typical number of turns is 40 - 100.


Ease of construction due to the amazing Neutrik modules with switch.


Other variations can include impedance matching transformers. Step up transformers with switched primary in order to low cut and at the same time make up gain.(decreasing primary turns increases cutoff while increases step up ratio).



Impedance matching transformers with deliberate low primary inductance to compensate for excessive bass boost of vocals at close mic distance due to proximity effect. Ambient low frequency noise noise is canceled.


Pop filtering due to electromagnetic damping. (the lower the frequency the lower the impedance of the inductor in parallel thereby converting voice coil movement to heat.


Neutrik connectors and Magnetec cores are the most beautiful worldwide.


Pleiades public domain dedication.


More details:


Directional (unidirectional cardioid) microphones boost bass frequencies progressively below 1 KHz when a singer is closer than an inch to a microphone, the usual case.


The amount of boost can easily be heard experimentally (in practice) or seen in any directional microphone data sheet Shure for example. This can prove an advantage as we shall later see.


The low cut filter of most consoles is at 100Hz giving erroneous results and we are all familiar with the unnatural bass heavy voice when a singer is close to the microphone for  avoiding acoustic feedback. The amount of bass boost as seen on curves is inversely proportional to the mic source distance and can as high as +15dB at 200Hz.


The Pleiades filters intends to give a flat overall response at the usual different close preferred microphone  mouth distances. It may be thought to act analogous to a macro camera focusing lens for very near objects.


Added advantage is a very high signal to noise ratio capturing the detail of the faintest voice even in high ambient noise environments. (Bass environment content is dramatically reduced while voice remains natural).


The Pleiades filter consists of just an inductor in parallel with the mic output signal. This gives the added advantage of electromagnetically damping the mic membrane and dramatically reducing pop and wind noise.


Magnetec makes possibly the best noncrystalline magnetic cores and Neutrik the best modular connectors. It seems natural to combine these elements to make a state of the art variable Pleiades filter.

Using Neutrik adapters, modules for Pleiades microphone filters and transformers

The Neutrik modules would be excellent for assembling a variable proximity compensating filter, cascading many Pleiades filters and switching with binary code combinations. Similarly for variable primary Pleiades microphone transformers.


The D shape adaptors would be great to accommodate large Nanocrystalinne tape wound cores for microphone matching transformers and moving coil cartridge matching transformers (passive pre preamplifier).


Neutrik connectors are the most beautiful worldwide.

Can a Pleiades Electra headphones tube amp be made with just one PCC88 or ECC88?

Preferably PCC88.


It may be possible if positive grid bias is used to increase anode current and gm.


The higher battery voltage source will supply and under heat if needed heaters and also supply anodes directly through the high impedance headphone windings.


Oops, the heater is 7V which is not very high. Perhaps 2 PCC88 can be used heaters in series. This will allow under heated operation (which seems desirable) at 12V supply. 12V for anodes should be great as a doubling of voltage quadruples power, P=(V squared) / 2.


The 2 paralleled triodes for each channel will also reduce output impedance to half .

Can a tube mic pre pre amp be made that operates on 1.3 Volts?

An electrometer tube can be used as shown in an earlier entry.


But can a PCxxx or PFxxx type be used?


Since their heaters operate at 4V, 1.3 Volts may provide the right under heating needed for low anode voltage operation.


Positive grid bias may do the trick as well as output transformer use so that the plate (anode) can be supplied  with 1.3V which is already too low.


The trick is to find a tube that is high gm and vary gm (variable tranconductance) as they have uneven grid spacing. Pentodes are very suitable since when triode connected the 2nd grid (screen grid) acts as an anode and is very close to the cathode to attract electrons.

What liquid can be used for solar heaters, Τι υγρό χρησιμοποιούμε στους ηλιακούς θερμοσίφωνες

Με δικη σας ευθύνη.


Διαβάζοντας το datasheet της BASF για το Glythermin P44
http://glythermin.ru/d/599572/d/ti-glythermin-p44.pdf

 
έχω την εντύπωση ότι το Glythermin 75 είναι Glythermin P44 25% κατά όγκο δηλαδή 25 Glythermin P44 και 75 νερό. Ψάξτε το μονοι σας και δοκιμάστε με δικη σας ευθύνη.


Έτσι τελικά αγόρασα 1 λίτρο Elton's Iliothermine  που είναι και αυτό βασισμένο στην προπυλενογλυκόλη  (propylene glycol) και πρόσθεσα 3 λίτρα απιονισμένο AB 365 νερό. Το Elton's το βρήκα στο μαγαζί με τα φίλτρα νερού στο metro Νέου Κόσμου με 10 euro.


Try at your own risk:


By reading  the datasheet of  BASF for Glythermin P44
http://glythermin.ru/d/599572/d/ti-glythermin-p44.pdf


I get the impression that the -10oC Glythermin 75 used in Greece is  Glythermin P44 25% per volume i.e.  25 parts Glythermin P44 and  75 parts water?.


I eneded up using 1 liter of  Elton's Iliothermine  which is also based in propylene glycol and added 3 liters of distilled water..

Pleiades 1:10 microphone input transformer

Turns ratio approx 35 to 350.

Proximity compensation due to 47mH primary inductance.


Secondary inductance 5.1H.


Fully balanced and symmetric input and output coil.


Wound on Magnetec 060 nanocrystalline toroid core.


Secondary wire diameter 0.1mm.


To be used with an early beige MD421 feeding 2 Pleiades stages of battery powered EF183 electron tubes.

Microphone Systematic Error

The bass reduction during the first few minutes was apparently due to the MD-421ii used in the experiments. It sounded great even with no proximity compensating filter. Following entries attributing cause to warming up tubes etc should be edited.

Can a JFET be made to behave like an electron tube?

Could it be that adding a diode + resistor to a JFET across gate make it have automatic gain control for many Megohms Rg or simulating electron tube instant clipping behavior with few MOhms Rg?


The rectificating grid action of the electron tube at large signals increases negative bias, therefore decreasing current, therefore Gm, therefore gain. Vary Gm tubes with deliberate uneven grid must be doing the job even better.


This was first shown to me when I disconnected the capsule from a U47 and applied a signal from a sine generator with 10Db steps. When a large signal was suddenly reduced by 10db gain was increasing by a time constant (coming back to its normal value after automatic gain reduction!), output of VF14 electron tube was an undistorted sinewave all the time.

How to reduce excessive bass and pop filter when your Shure SM-58 is used at a very close distance

How it's done:


Some turns of insulated wire are wound on a toroidal ferrite or nanoperm core. The 2 ends of the inductor are soldered in parallel with the SM-58 voice coil. The core in this example must have been a Philips ferrite wound in around 2008? with 24 turns of wire wrap wire.


How it works:


If one speaks closely to a directional microphone bass increase takes place due to the proximity effect, which is an effect in some way analogous to what causes a tide (difference of gravity from the sun and moon on top and bottom of the earth, the moon is more effective as the difference between top and bottom is greater because it is nearer to us).. [1],[2].


An inductor has an impedance which drops with lowering frequency. At 0 frequency all you are left with is the resistance of the wire. It therefore short circuits low (bass) frequencies.


Inductors (coils) in electrical syatems are analogous to mass in mechanical system and therefore obey the analog of Newton's 2nd low. It says the more slowly you accelerate a mass the easier it is. Try moving back and forth a door at low and then high frequency. In electrical systems current is velocity and voltage is force. An inductor tries to keep current through it constant just as a mass tries to keep speed constant. The slower we move back an forth electrons in an inductor the easier it is, so bass frequencies are short circuited, the easy current makes a large voltage drop in the voice coil resistance. Similar to the rotating speed of a juice extractor dropping when you extract the juice of a fruit. This is conservation of energy and this energy converted to heat is what also acts as a brake to the membrane moving at low frequencies reducing pop and air blasts when the inductor is connected.


More wire turns more bass, or alternatively less turns more treble. Amazing clear treble.


Inspiration for the Pleiades filters came from  the Director of Acoustical and Electromechanical of RCA H.F.Olson in his article: H.F. Olson, Ribbon Velocity Microphones, JAES, 1970 June, Vol 18.
An inductor is connected to the secondary of a ribbon microphone transformer


On this example the inductor is connected before the in house transformer of the SM58, right to the voice coil where the impedance is very low. This makes the construction very easy as very few turns are needed. The primary of the step up transformer is left connected to the voice coil as usual the step up the voltage and therefore impedance to 300 ohms.


Ref:

Hewitt, Conceptual Physics

Hadden, High Quality Sound Reproduction, BBC

 H.F. Olson, Ribbon Velocity Microphones

Pleiades Electra JFET Headphone Amplifier No Components

This is a source follower and the headphone coil (one for each ear channel) acts as the source resistor itself.





Some idea as on electron tube Pleiades Electra 1 and 2 where the headphone coil is the cathode resistor or the plate load resistor itself.


This is a brilliant idea that comes from the book Audio Amplifiers, Editor J.R.Davies, Data Publications, page 41, 2 - Transistor miniature AF amplifier. The AD140 power Germanium transistor has as load resistor the 15 ohms speaker itself. Class A, as electrons flow all the time, bias from collector to base, as simple as life can get, and amazing sound. The Idea also comes from another book by "uncle" Clive Sinclair, Transistor Audio Amplifier Manual. Hi impedance earpieces are used instead of collector load resistors, life is so beautiful.

Pleiades 12V battery powered 12AU7 microphone pre preamplifier or DI with positive bias resistor from plate (anode) to grid to free electrons

This is a mod of a pre amplifier made in around 2000 using an ECC86 which did not work quite well. Many years later it was replaced with 12AU7 at 12V and then after some time  the other end of the 10Mohms grid resistor was connected to Anode where it started to sing.







 Inside view showing 10MOhms from plate to grid. ECC82; sounds great but EF183 is possibly more suitable for low voltage positive grid bias work.

Pleiades K117 JFET battery pre preamplifier 2nd prototype

This is using a FREED input transformer of about 1:60 ! turns ratio and primary inductance of 40mH.


Great for compensating bass proximity effect, amazing sound using an MD-421 foe intimate vocals.


Since this is a source follower of low impedance it can be connected to the input of  a V72.

Pleades K117 JFET microphone pre preamplifier schematic

Thanks to Panayiotis Diamantopoulos who gave me the transformerless schematic.

The art of Music, Electronics and Psychoacoustics

Sound or music comes to our ears by air molecules striking our ear membrane.


When one hits a drum, the drum  membrane vibrates, sets to motion nearby air molecules, which by collision set to motion nearby air molecules until those near to our ear vibrate too.


This transfer of energy is called a wave. It is interesting that the energy flows not the molecules. Like sea waves, water is not transported it is the energy that does.


It is also interesting to note that even in complete silence molecules are random vibrating. The energy is ultimately coming as everything in our planet from coalitions of photos from the sun. It is called thermal motion and depends on temperature. When temperature of water for example is high water molecules vibrate so quickly that they can escape into air, the water boils.


We cannot hear thermal motion of air molecules (silence), because the sensitivity of our ear - brain mechanism is set just on this threshold.  Otherwise life would be difficult hearing a meaningless hissing noise all the time.


Information occurs when something unexpected happens. When a someone sings a note or speaks the air molecules have an extra much larger superimposed vibration.


The simplest tone containing just one frequency is from a tuning fork that last infinite time.


Frequency in the number of complete cycles of a vibration occurring in 1 second (Hertz, Hz). A tuning fork vibrating 440 times per second has a frequency of 440.


It is the note A4, (la 4), the highest la that a man can sing.


An octave is a similar sensation but on higher or lower pitch. It is a close to a multiple of 2 but not exact. So the highest woman la would be somewhat higher than 880Hz. The confusion arouse because in electronic engineering it was found convenient to define an octave as an exact multiple if frequency.


Pitch and frequency are not the same, the first is the psychological impression the other is the objrctive measurement. Pitch obviously increases as frequency increases but also depends on intensity. For example if you listen to a YouTube clip containing a tone of 440Hz you will find that pitch drops appreciably as you increase the volume.


Electronic signals have many common with acoustic signals, the main difference is that instead of molecules we have electrons vibrating.


Electrons are so small that we cannot see, they have negative charge and have the peculiar property that when an electron in universe vibrates an electromagnetic field emmited makes another elceron in the universe vibrate similarly.


For example electrons in the sun make electrons in objects and in our eyes vibrate. Therefore we can witness and see beauty.
.

The waves that make these happen are called electromagnetic and again it is not electrons that move but the energy that flows, furthermore they can travel through empty space.


Electronics is the part of art science and engineering that deals with the control of the movement of electrons.


Sound carrying air molecules striking the membrane of a microphone set in turn corresponding vibrations in the wire coil attached to it. So a microphone converts the vibration  of molecules to similar vibration of electrons.


Vibrating electrons in a metal wire set into vibration the ones nearby and so on up to the other end. The wave is traveling and not the electrons.  The  electromagnetic wave is traveling at the speed light in the material the conductor is made of.


The tiny movement of electrons can be made larger. This is called amplification.


Electronic noise exists in conductors in the same way and it is the random thermal motion of electrons.
We can certainly hear this random motion as hiss if we turn up the volume in any amplifier when there is no music loud enough to mask it


In the beginning of the 20th  century amplification was made possible by devices called electron tubes where the control of the movement of the electrons is done in the vacuum of the evacuated glass tube.


Since then smaller devices called transistors have been invented which have evolved to be so small that billions if them may exist in the processing chips of a smart phone.


The electron tube or vacuum tube faults make them very attractive to the production and reproduction of music.


Almost always tracing the origin of a hit song we will find more than one electron tube in the signal path from production microphone to the listener loudspeaker.. An obvious contemporay example is the use of the 1947 made Neumann U47 microphone having inside the VF14 electron tube. Such a mic can be seen for example in  the Christina Anguilera video clip on recording Say Something.


A reason for tubes is the way they overload from a music signal mimicing the way our ear - brain overloads. There will always be overload as music is a tremendously dynamic signal and overload is a desirable thing compressing a large dynamic range to small so that one can hear loudly radio in the car without quite passages be masked by noise or louder ones overloading your laptop. The tube is made to overload so that the digital circuitry does not overload abruptly as it runs out of 1s. (11111111.... in a 16 bit coding digital system).


Music is the art and science of conveing emotions from the brain of the composer to the brain of the listener .


In practical terms it consists of melody, bass and harmony.


It consists of repetition and surprise but it's ingredients is melody bass and harmony.


((((( apendix on impedance
If an ant collides on a elephant, not much happens it may just bounce back. They have vastly different mass. In energy flow terms this is called impedance mismatching. A mismatch makes the energy being reflected back. Same when we look our selves to the mirror. Or if we talk with both palms in front of our nose on a non reflecting space like a beach.
If an elephant runs to collide with an ant again there is no much transfer of energy from the point that almost all of the elephants kinetic energy stays within the elephant and may put the elephant in danger if stopping in not done on time.


Difference in impedance is what make the waves bounce back at the end of a open organ pipe. Or reflect at the end of the guitar or piano string fixed at it ends. A similar reflection happens to the walls of a cathedral making the acoustic huge. Similarly as impedance mismatching mirrors on opposite walls make light waves echoes re reflect making the room look huge.


The trapped energy is called standing waves. In the strings the multiple reflections establish a repeating patern which produces the note we hear.


Strings can vibrate in may permissible modes. This produces harmonics.


Harmonics in turns produce the notes of the C major scale.


From 7 notes all music already existing and future can be made.
How we will shortly see. )))))


Melody is the mystery. We do not know where it comes from and it can happen to anyone whether musically educated or not.


Bass as the name signifies comes from the Greek basis meaning root or base and is the foundation of music where all harmony springs from it.[ JS Bach intructions to his students on figured bass]


Harmony is the combination of different notes sounding together.


Since there exist 7 only notes which repeat themselves at different octaves there will be 7 bass notes too.


The natural or common harmony when not something different is specified is produced by adding the 3rd and 5th  (1 3 5 law) note on the right hand. So the bass being C. The right hand can be 1 3 5 ie C E G.


The most famous example would be opening chord of Imagine - John Lennon, bass being C and right hand using the notes C E G as a sequence of E G. Together then C then E G then C and so on to include a rhythm structure. Then after a while the bass becomes F and the natural law of 1 3  5 would r quire F A C, which is exactly what is done and this chord is called F major. Having a song with A on bass (second chord of Alone - Hearts) would require A C E. This time the chord is not called A major but minor due to the asymmetry of the keys of a piano. a to c has fewer semitones steps than c to E.


D on the bass naturally requires D F A an obvious example is the opening chord of Requiem in D minor. - Mozart.


Since there are 7 notes available for the bass there would be 7 chords that can be made (using the 1 3 5 law) and if we normalize any music piece to the C major scale ( using all white keys only we can play with both hands on a piano almost any musical piece ever written with just these 7 chords at the correct order the composer choose.


What makes the beauty of music further flourish is to depart intentionally from the 1 3 5 law to create further colors in our palette. A different code could be 1 4 7. An example is  2nd chord on Requiem - Mozart as the bass plays F and the right hand D A.


We can have many different codes and this is one of the reasons music can have an almost infinite variety even in its micro structure. Some of these combinations like 1 3 5 and 1 4 6 are called consonants and other are called dissonant such as 1 3 9. It does not mean that they do not sound agreeable. A beautiful example of 1 3 9 is third sung word of Close to You - Carpenters (in the sung word birds, the sung G is 9 notes above bass F) . Another example is the first  chord of Just Hold Me - Maria Mena again a 9th chord.


Another example is the  3rd chord of Qui Tollis  from Mass in B minor - J.S.Bach.


Much of the skillful art of music is the balance between consonants and dissonances as J.S. Bach explains and how 7ths and 9ths are prepared for our brain.


 A useful rule is taking the third together with a 9th so 7th.  An example is the 3rd chord of Bachs. Air where the bass plays G the right hand plays the prepared 7th note of the scale (D major scale in this piece) which is  F# and the other instruments play th 3 rd B and D (5th). The reader us reared to the instructions to his students in music by J S BASS.


Orchestration being a subject in itself includes knowledge of masking theory.


An overlooked but extreme,y import knowledge to anyone involved into.making music is the knowledge of the Fletcher Manson curves. These show by experiment how the sensitive of the ear brain mechanism changes according to frequency and most importantly  the intensity level of this frequency.


Having its practical origin to survival a very faint sound pressure level from a crying baby in danger emitting mid frequencies to the most sensitive mid range ear at low levels. The ear surging to catch up in sensitivity at low and high frequencies as iintencity levels increase. An obvious example is that by turning up the volume in a radio we start to hear not only louder but fuller, bass and treble perception coming to play.


If bass and treble frequencies are not reduced during recording or mid boosted by a high quality inductor equalizer  the usually higher intensity in reproduction will make a voice sound bassy boomy and spitty due to bass and high frequency predominance compared to mid range.


Although it is easy to assume that one must record and reproduce flat it proves that one has to deliberately  make a mistake to to counteract natures "mistake " so that the correct natural and pleasing balance results.


This may seem contradictory to signal theory requiring that flat reproduction will produce an undistorted signal. This would be true if our signal path would be from production microphone to reproducing loudspeaker.


Actually the signal path is from  the vocal chords of the performer to the brain of the listener or the brain of the composer to the brain of the listener.


So we  have in our disposal all those molecules of air and electrons to tell them what they should do.

How to hear the true quality of you voice

Find a quiet outdoor place, eg beach, forest ...


Join your palms and touch your small fingers to your nose.


Speak or sing, enjoy!

Happiness Inside Only

1st Pleiades High Cut Filter

Yesterday was made the 1st Pleiades high cut microphone filter inside an XLR adaptor.


The idea was :

to compensate for increased high freequency content due to mic proximity (obstacle effect)


to compensate for Fletcher Manson and voice effort curves


It consisted of only one 220 nanofarad capacitor in parallel with mic output.


Theoretical cutoff 3.5KHz assuming 200ohms Zo of microphone.


Is this still 6db per octave or does it make a reasonant circuit with the Pleiades low cut inductor filter in parallel too?


When it was connected any unnatural hiss left was almost extinct and it was found more desirable to further cut bass for balance. Values up to 25mH were used, (1.27kHz). At an output stage it would round off peaks of instantaneous limiting!


Signal path:


MD421 - Pleiades high cut - Pleiades low cut - Canford input transformer - EF183 with positive bias


Sound had quality of Say Something - Brave New World, Anguilera

Hapiness is Around

Nothing Gets Lost

If you give freely, it will come back in multiple ways.

How to Stop an Addiction

A simpler way to calculate daily dose can be the following:


For example, one smokes 20 cigarettes per day and feels a comfortable dose for next day is 19.


Step 1: Dividing 19:20 = 0.95.
This number can be used to find dosage for every day by multiplication.


Day we start dosage  : 20 cigarettes


Next day : 20 x 0.95 = 19 cigarettes


Day after : 19 x 0.95 = 18.05 cigarettes


Day after : 18.05 x 0.95 = 17.14 cigarettes
..........


Day seven :  20 x 0.95 x 0.95 x 0.95 x 0.95 x 0.95 x 0.95 x 0.95 = 13.9 cigarettes


(Note as time goes by the rate of dosage reduction decreases, greatest reduction is on 1st day)


So if you can comfortably cope the 1st day you should be able to cope all the rest until dosage is 0

How to Stop Any Addiction

Theory : That you want to stop it.

And now to the practical part.

Step 1 : You decide how long it should take you, and you write this time on the horizontal (time axis), example will be given.

Step 2 : You write on top of the vertical axis (dosage axis), what is your current dosage.

Step 3 : You draw an inverse exponential curve as drawn on the example

(An inverse exponential curve has the property that at equal amounts of time the dosage becomes half)

End of story, you follow the dosage as given on the curve, good luck.

(I am not a doctor or you do at your own risk)

Example : Say you smoke 20 cigarettes per day and you choose to have stopped smoking  within 6 months:

By drawing on a large mm paper and dividing each month to 30 days, with a 90 degrees triangular ruler you can calculate cigarette dosage for each day.


This technique has already been used with success on 2 individuals for quitting Cipralex, Entact, Escitalopram antidepressant by measuring each daily dose on a small micro gram electronic weighting scale bought on eBay.

Flying Over Aegean - George Chakiris parts score

A little piece I dreamed of.


Public domain dedication.


Rough demo on YouTube :



https://www.youtube.com/watch?v=Gfo9_u9cjxI</div>

Pleades 4.8V super quiet microphone pre pre amplifier booster with EF183 triode connected and 3.9M positive bias from anode to grid

The idea comes from Hliana who insisted on positively biasing grid to free electrons.


Assigned to public domain by George Chakiris.


This little pre preamplifier makes a voice appear times bigger.


YouTube clip of earlier prototype with 6V lead acid battery and 4R7 dropping Resistor.
https://www.youtube.com/watch?v=xPVtXzmfDR8


Please note heaters are under heated to reduce information obscuring electron cloud.


This prototype was tested with Sennheiser MD421 feeding a Canford  low to high impedance converter (419mH transformer primary) feeding pre pre amplifier feeding a Realistic Disco Mixer at its mic input.


Component list:
4x AAA batteries (through fuse they supply heaters directly and anode through Ra) (neg to cathode)
1x fuse holder (very important to protect yourself and the batteries)
1x 0.8A fuse (will be reduced as heater current should be around 260 mA, initial 500mA)
1x EF183 electron tube (EF183 is vari mu, high gm) (in this amp grid 2 and 3 are connected to Anode)
Ra=15K (10K shown)
Rag=3.9MOhms (positive bias resistor from anode to grid to free electrons)
Ci=220nF ( very important input capacitor to keep grid free )
Co=1uF (output coupling capacitor)


Proximity low cut off can be adjusted by the primary inductance of the input transformer. A Pleiades input transformer can be made with 70 - 300 mH so that extremely detailed and clear vocals can be obtained at a distance of 1-2 inch from microphone. The closer the distance needed the less the inductance making construction easier as fewer primary turns are needed. An excellent example of magnetic core is Magnetec's series of nano crystalline extremely high inductance index toroidal cores.


With just 3 AAA (3.6V) it performed even better and perhaps more quietly but gain was lower. Grid bias was close to 0 compared to  -0.4V when 4 AAA were used due to increased negative electron cloud making cathode more positive with respect to grid?)


Very nice performing with electric bass too.
Signal Path:
Yamaha electric bass - Pleiades pre pre - 50K to 500Ohms impedance converter - Realistic Disco mixer mic input
Extremely quiet bass operation and great tone




Schematic of pre preamplifier showing experiments of connecting Grid resistor to various points. Maximum anode current was as expected obtained by having the other side connected to Anode. This does not mean that grid is positive but it is certainly less negative. Being positive or not depends on cathode temperature, lower temperatures reduce electron boiling cloud and this can make grid positive with respect to cathode.

Pleiades Electra 1.3V electron tube pre preamplifier with CV2269 electrometer tube and positive grid bias from positive heater to grid

Pleiades Electra 2 picture with wiring shown

Systematic error in folowing 3 entries

For some reason the MD-421 - Canford step up - EF183 - started sounding bass heavy.


This may be to bad resistive, capacitive contact cleaning itself.


Or the grid of the EF183 may had been blocked and unblocked it self?, Today and previous day sound started off fine and withing 3 minutes of tube operation bass heaviness suddenly came to play without apparently touching anything.


Trying to compensate for bass a few Pleiades filters were added. (200Hz and higher up to 800Hz) But when the deep bass was cut remaining treble was too high.


So it was decided to remain at the 419mH Canford primary inductance and add a second low cut pole adjusting the coupling capacitor from the EF183 anode to the disco mixer mic input.


22nF made the sound clear as it had been before.


This indicates that 2 different low cut filters need to be used.


Same principle seems to apply to the Grampian ribbon mic. Of course much lower primary inductance will be needed.


Further experiments need to be made including connecting an EMI RS106A which is a 12dB per octave Low Cut and High Cut filter.

Extra bass reduction for ribbon mics

Using the Grampian ribbon mic on various experiments it was best found to low cut with a Pleiades filter or transformer of about 2.3mH input inductance.  This value gives a natural mid and treble production. Of course it can be fine tuned according to need


Further low cut if needed may best be done by other ways, in our experience nets it was done by varying the coupling capacitor from anode to mixer a series resistor of 10nF to the usual 1uF was typically used.


The Sennheiser MD -421 does not need a extra low cut the
Pleiades 19.5mH giving an excellent bass responce at a mic - mouth distance of less than 1 inch. This may sound contradictory with following entry with Canford input transformer of 419mH. At 19.5mH even cutting all treble, the bass still sounds unexagerated. More work needs to be done to decide. The MD421 inherent bass cut makes the experiment more difficult.


Electromagnetic compensation due to the inductor short circuiting the low frequencies is very effective as a pop and wind filter.


The extra treble due to close distance exaggeration was not  reduced  with a shunt anode capacitor as described below.

A clip can be heard on YouTube's Pleiades Radio channel 4th broadcast. No treble cut was used and if I remember well a Canford impedance converter (419mH measured primary inductance) was used as step up. This step up as documented is  feeding a EF183 Pleuades 4.5vVbattery pre preamplifier with 3.9Mohms from anode to grid for positive (less negative) bias.

In fact treble cut must have been used as the cable capacitance makes a high cut filter with the Pleiades electron tube preamplifier output impedance.

Treble reduction for correct brain perceived voice production and reproduction

The experiment below was also done with a Sonotone crystal microphone connected directly to the grid of EF183 electron tube through a 220nF coupling capacitor.


Since the Pleiades connected EF183 with a resistor from anode to grid has an approximate 100k input impedance, bass is already compensated thanks to  the microphone's effective series output capacitance (making a low cut filter with the 100k impedance.


The excellent sound was high cut with a anode shunt capacitor of the order of 10 to 33 nanofarads.


The Grapian ribbon mic with 2.3mH Pleides input transformer did not need much any treble reduction as natural sound was already there.


There was some exceeds bass which could be further cut with a 10nF coupling capacitor from anode to the mixer mic input.

High Frequencies must also be reduced for natural voice production

A Pleiades filter or Pleiades step up transformer can be used to reduce unnatural bass frequencies due to

Soft speaking or singing (voice effort compensation)

Higher level reproduction (Fletcher Manson curves)

Proximity bass boost of microphone

When we achieve an amazing clear bass on voice we are left with a  high frequency content in voice due to

Soft speaking or singing (voice effort spectrum curves)

Higher level reproduction (Fletcher Manson curves)

Mic obstacle effect (mic is very near exaggerates high frequencies)


One effective way to attenuate HF is to add a capacitor from anode to ground. On the Pleiades EF183 pre amplifier Vb=4.5 volts values of the order of 10nf did a fine good in compensating the treble boost perceived.

Further advantage is the reduction of any hiss left.

Another great advantage would be the rounding of peak limited waveforms when more than one stage of tubes is used. This should give a louder subjective voice at smaller objective waveforms with distortion content reduced due to high cut.


The above one tube stage experiment was done with Sennheisr MD-421 - Pleiades 19.5mH 1H step up bass proximity compensating input transformer - EF183 Ra=15K
Ra-g=3.9M  Ci=220nF Co=1uF - mic input of Realistic Disco Mixer


This perhaps is not a very good example as 19.5mH is too low for MD421 cuting more bass than needed.


Very natural voice sound was produced with Canford Audio impedance converter XJ matching transformer .With MD-421 bass cut setting in the middle, mouth distance at 1in, feeding directly the Realistic disco mixer sound was dull and rather mechanical. Feeding the EF183 Pleiades stage which then fed the mixer the sound was great with full body, great treble and mid, and the easiness associated with electron tube circuits. The input impedance of the positive biased stage from anode to grid with 3.9MOhms should have been about 100K. High frequency content reduction was not needed apart for the subtle effect of the cable shunt capacitance high cut filtering.

What is Fear

Fear is an invention so that some can have a good time at the expense of others.

World Recording Museum

Better title to be found.


After a brainstorming session with Sotiris Moutsatsos and Dina Athanasiou.


Specifications:


1. Restaurant
Only fresh juice and top quality Barley Rusk based food with toppings, musical instrument sweets.


2 Shop, e-shop
Selling vinyl records , sound technology and music related books, top quality audio files etc.


3 Sound Reproduction level
Reproduction systems of all decades from 1920's to future state of the art.


4 Sound Production level
History of all pro sound recording equipment up to state of the art recording studio operating with all gear from 1920s to future demo equipment. Includes synthesizers. Producing recordings for visiting musicians.


5 Live level
Concerts with live binaural streaming, (museum radio station), audience participating etc.


6 Lectures
Top world known producers and musicians invited disclosing their art.


7 R&D Level
Research and development, production of recording equipment, techniques, publications.

Can a Pleiades electron tube Preamplifier be used by NASA as front end detector?

The Pleiades pre amplifier is different in 3 respects.


1 It uses positive bias from plate (anode) to grid via an external high Megohm resistor allowing an electron tube to operate as a low noise-figure amplifier at very small power supply voltage (<10V).


2 It deliberately uses reduced heater voltage reducing electron "boiling" cloud around the cathode which seems to obstruct information extraction.


3 Low voltage operation permits the use of battery or solar panel supply which is the quietest source of energy on our planet with very high bandwidth.


Hopefully the circuit may be a basis of beneficial experiments as a front end preamplifier. This may lead to better resolution pictures on radio telescopes or delving deeper into the past, amplifying the faintest signals of the univesce coming electromagnetically from space.

A Great Way to Amplify tiny signals with tubes is to Reduce Heater Voltage and Positively Biasing Grid with a Megohm resistor from Plate to Grid

Revisiting EF183 at small supply voltage (Vb=6V battery) for amplifying  small mic signals (front end) it was observed that the grid assumes a -0.5V when left alone. This was measured by a high Z voltmeter approximately 10MOhms input Z.


When plate (anode) was disconnected from Vb, Vg was -0.65V !!!


So in the absence of any connection (just normal heater) there is a potential difference of -0.65V between cathode and grid! By connecting a micro ammeter between grid a cathode a current of 100 micro amperes was measured, and this in the absence of any power supply other than heater voltage.


Experiment with a EF183 battery pre preamplifier:


Signal path:


Grampian ribbon mic - Pleiades 2.27mH -2.8H (1:32) proximity compensating transformer (8turns to 249turns on Magnetec 073 core - 22nF coupling capacitor to grid - EF183 (triode connected) Vb=6V 6.8M from Vb to Grid (otherwise the electron tube does not have enough anode (electron) current, (Bravo to Hliana) - Altec 15095 output transformer - Realistic Disco Mixer at mic input - attenuating pad 560ohms etc at output - Sennheiser HD-580 Headphones


Sounded nice but disconnecting heater from its supply made the sensitivity of the microphone increasing! while Ia was decreasing! until the temperature of the  cathode was so low that one could hear granular emission noise.


A 22Ohms 2W dropping wire wound variable resistor  was connected in series with the heaters


At full heater voltage Ia was 300 micro ampere. Things were starting to get really interesting sound wise at 100- 140uA ! This was when maximum gain was observed by having a 440Hz square Seiko  metronome at 440z  at a couple of feet from mic.


Vh was measured to be 3.14V !. , heater current 180mA !


At this point subjectively the sound on voice was amazing having the quality of the legendary U47 microphone were genius Georg Neumann was using 34V on the 60V heater of the VF14 electron tube! Great detail on the subtlest nuances of voice.


Amp did not seem to work with R (Vb -G) of 8.2M.(why? did not as a sencond step try to reduce Vh when it was connected? (at later experiments it did, optimum Ia current was found to be 105 micro amperes by letting the heaters to cool down by disconnecting heater supply and observing maximum information heard on headphones.


Next high resistors were connected from Anode to Grid (not Vb to Grid) as this was found to give an even more ethereal subjective quality to sound.


By accident 8.2M was connected, max gain was when Anode current was around 105uA !!, Vh=2.6V !!!, Rh=17.5Ohm


2 stages of EF183 was connected one after the other, the 2nd (Ra=1.5K, Ra-g=3.9M). Sound was still clear so need 3 stages.


While doing these experiments it was observed that when connecting 6.8M from Anode to Grid Vg=-0.5V becomes -0.2V when there is plate supply and -0.4V from 0.65V when there is not (open)


Next day:


It seems that the electron cloud around the cathode behaves as traffic masking signal in an information way, not a noise way!


It had been previously also observed that this -0.5V decreases when heater voltage is dropped.Time constant giving same behaviour as sound increasing!


Only heater voltage was supplied to the EF183. Then the usual -0.8V was observed. Another way of looking at it is the cathode is depleted of electrons and becomes positive or grid absorbs some electrons and becomes negative? A similar voltage somewhat lower was observer on the A, g3, g2 combination.
By connecting a uA meter between grid and cathode with no other supply than the heater voltage a substantial current of 200uA !!!(120uA systematic error?) and a current of 3uA between Anode and cathode.


When the heater was connected to the dropping resistor giving max gain, this grid cathode current was increasingly being reduced ascathode temperature was decreasing and final went to 0!! at a time constant of a about 10 seconds similar to the time constant for observing max signal to noise!

A mic preamplifier with JFETS and electron tube with peak limiting for ADC iPad Garageband etc

A good combination was 2 stages of K117 (4.7K all resistors, 2.6V) driving 2 stages of a 12AU7 Vb=12V or one stage of varymu EF183F triode connected Vb=6V. AN ATTENUATOR WAS CONNECTED AT THE OUTPUT (50K2 ALPS blue potentiometer).


So signal path was:


Grampian mic - Pleiades 1:30 2.2mH - K117 - K117 Vb=2.6V - EF183 Vb=6V  Ra-g=3.9M Ra=1.5K - ALPS 50k - Realistic disco mixer as headphone amp - att pad - HD-580


Other variation was 2 maximised gain stages of K117 Vb=6V 33K 4.7K separated by 100K potentiometer


nice at 9% of pot, compressing at 16%,  very loud dist on 26%


Need to try lower gain versions on K117 with 3.3K-3.8K  10K Vb=2.6V which are higher than 4.7K 4.7K

maximising gain on K117 JFETS

Values found by experiment. (Rs bypassed with 47uF)


Vb=1.2V
Rs=3.4K Rd=3.32K  or
Rs=5K    Rd=5.4K    or
1.78K      1.7K      lower than above


Vb=2.6V
4.25K   11.7K    or
3.36? 3.78?     1oK


Vb=6V
1.24K 1.37K?    10K
4.5K     33K    very high +4dB than max at Vb=2.6V

An electron tube biased with a resistor from Anode to control Grid acts as a compressor - limiter

The experiment was about listening to how an active device overloads in real time from a live mic signal.


Signal path :

Grampian ribbon 35ohms mic - Pleiades 1:30 tranformer with 2.2mH primary - K117 Pleiades stage with 4.7K both drain and source resistor (VB=2.5V) - another ditto Pleiades stage - 1/2 12AU7 Pleiades stage, cathode to ground, Ra=33K, Rg=10M, Vb=12V!, 2/2 12AU7 Pleiades stage, cathode to ground, Ra=10K, Rg=10M, 50K, 436ohms divider - realistic disco mixer mic input - headphone atten pad - Sennheiser HD580


After noticeable distortion the 10MOhms resistor was removed from the final stage and a 3.3M was connected from grid to Anode!!!. Sound was grand! At such conditions anode voltage was 9.7V, Vg was -0.3V when no signal input and Va=10.7V and Vg=-0.7 when singing, inbetween values when speaking.


Output VU meter on disco mixer showed no increase from +3 even after singing quite loudly indicating limiting. Subjectively sound was getting louder and louder are harmonics were gradually being generated by the process.


Then the 12AU7 stage was replaced by the Pleiades triode connected EF183 stage powered by 6V and Rg=3,9M from anode to grid. Vg was measured to be -0.58V.


As this was 1 stage only it seemed to compress more than limit. It needs to be found if vary mu tube do compress more than limit.


A useful further experiment could be to supply the grid through a fairly high resistance and high voltage so as to make a higher release time (grid would discharge the charge it has accumulated when overloading more slowly.

Singer's Vibrato in slow motion

This can be heard by clicking on YouTube on the low right hand of the screen on the "gear" settings icon and selecting 0.5 speed.


Have tryied it on Kazantzidis - to pelago einai bathu, Maggie Reilly- to France, George Michael - Careless Whisper, and Maria Callas - Bizet Carmen.


It is amazing to hear that good singers deviate about 1 semitone (frequency modulation) at a far greater than violins speed to produce their beautiful sound.

Pleiades Instantaneous Limiting

A great way to peak limit a music signal could be to use a Pleiades  transformer (operating like 2 tape heads facing each other).


The automatic pre emphasis and post emphasis needed to revert to flat would simulate a top of the art tape recorder with no tape running at a great speed.


Uses can be to drive loudly a digital system or an FM radio station chain. One could use a Pleiades amplifier but gently overloading a Pleiades transformer could be even better while employing  pleiades amplifiers for added advantage on limiting loud signals while making small signals loud and smooth.

Cascading Pleiades amplifiers

The simple signal path:


mic - pleiades transformer - pleiades preamp (1 stage)


sounds great but there is no peak control at all so when it is connected to a DAC  things get tough.


mic - pleiades transformer - pleiades pre (1 stage) - pleiades 1 stage)     sounds much better with tubes (a 12AU7  double triode 12V battery powered or 2 k117 pleiades jFET stages.They produce .euphoric distortion, 3nd harmonic, gentle peak limiting etc.


Cascading a third stage the distortion becomes apparent.


So in the 2nd K117 stage the 47uf source bypass capacitor was replaced with 68nf (to treble boost) and the drain resistor of the 3rd stage was shunt with 68nf to high cut. It sounded nice and strong and looking at the oscilloscope on could clearly see while hearing nasty harmonics disappear ( waveform rounded by adding the shunt capacitor!


Next step is to do the same by clipping a magnetic material (eg a pleiades transformer simulating the saturation in a tape recorder). Since the pleiades filter operates on constant current like a tape head all frequencies could be peak limited.

Pleiades instantaneous peak limiting

A great  way to instantaneously peak limit is to overload a non feedback tube or transistor amplifier.


This could further be improved by including pre and post emphasis. For example increasing high frequency content then overloading and then reducing high frequency content as used in FM broadcasting.


This has the advantage of rounding edges!. it has also been used in tube guitar amplifiers driving the  low pass speaker. Mike Oldfield conceived an ingenious technique of clipping a guitar on a tape recorder mic input then eqing to increase treble then overloading then eqing to decrease treble or something of that sort (more on a transcribed interview of Mike Oldfield on the web).


Tape recorders use the same amazing principle of low cut (head is constant current driven by a high Z amplifier, this gives 6bd per octave drop as in a Pleiades filter). Then the tape can be softly saturated ,the differentiated signal is the integrated (high cut), magic!.Most of the greatest sounding music recordings on our planet use this technique to advantage. Same with vinyl, pre post emphasis, RIAA.


It would be great to make a tape recorder with no tape. This could be done by using 2 heads facing each other and take to advantage pre post emphasis. Or use a Pleiades transformer wound on a Magnetec or noncrystalline core or other core to use B-H magnetic saturation curves for instantaneous peak limiting with the high cut needed to restore flat response and consequently rounding the instantaneously peak limited signal.

Opinions are like assholes, everybody has one. Clint Eastwood

an evolving Playlist with hit song ingredients

Playlist

7 Seconds Away - YN NC
A day in the Life - Beatles
A man and a woman - F Lai
A woman in love - B.Streisand
Abra Cadabra
Acapuclo Nights
Adagio Albinoni
Adagio Barber
Addicted to you - Avicci ?
Africa - Toto
Again again again
Against all Odds
Agnus Dei - Rossini
Air - Bach
Air Bach Lousier
Alive and Kicking
All of me when I lose I am wining
All of me - Evanescence
All night long - Lionel Richie
All night Long instr
Alone - Heart
Alpha - Vangelis
Always Somewhere
Amore Mio
An einai n agapn amartia
An m agapas - Spanos
An m agapas instr - Spanos
An thumntheis t oneiro mou
Anamnisis - The Olympians
Angels
Animal Instinct
Animals - Maroon
Another Brick in the Wall - PF
Any Better - Purescence
Apopse se thelw
Aqualung
Aquarious
Ave Maria - Celibe Dion
Back to black - amy winehouse
Bad Boy - Den Harow
Bals twn xamenwn o - X
Beautiful - Mandalay 7 Canny
Beautiful Maria - Baderas
Beautiful Things
Ben - Michael Jackson
Big in Japan - Alphaville
Blue Velvet
Born to be Alive -
Boys just wonna have sex
Breath - Pink Floyd
Brexei pali apopse poul
Brexei pali apopse
Brothers in Atms
California Dreamin'
Californian Girls - The Beach Boys
Canon in D - Pachebel
Careless Wisper Inst - G Michael
Careless Wisper - G Michael
Caresse sur L' Ocean
Chandelier
Cherish the Love
Chi Mai - Moreicone
Cinderela - Martinelli
Clocks - Coldplay
Close to you - Carpenters
Closest thing to crazy- Katy Melua
Clouds Across the Moon
Come into my life
Come undone - DD
Concerto Correli
Concerto in F - Mptzart
Concerto no 2 Rachmaninov Ada
Concierto d aranguez
Concerto D bennedito Marcello ad
Constant Craving
Copacabana
Could I have this kiss
Could this be Magic - Donna S
Could this be Magic - Manilow
Crash instrumental - J P
Crash - Jennifer Paige
Societys Child -
Da Da Da
Dancing cheek to cheek - fem voc
Darling
Den einai twra pia edw - Plout
Diamonds - Rihanna
Diamonds Are Forever
Don't give up
Don't you Forget about me
Do you know - Diamna Ross
Dove l' Amore - Cher Live
Down Town - Petula Clark
Dream On
Dreams Tge Cranberries
Dust in the Wind
Dws mou t athanato nero
Eagle - Abba
Earth Angel
Eclipse - Pink Floyd
Ekeivn - Boskopoulos
Eklapsa Xthes
Ella Elle l'a - France Gall
Eleonor Rigby
Ena kalimairi
Ena kalokairi instr
Ena Prwino - Xarxakos
Endless Love
Enjoy the silence
Epixirisi Apolon - Markopoulos
Eixirisi Apolon - Papayhanasiou
Esena pou se kserw toso ligo
Esu kai Egw - Hatzinasios
Et si tu n existais pas - J. Dassin
Ete - Amelie Comptine
Eternal Flame - Bangles
Eveybody Hurts - Corrs
Everybody's got to - The Corgis
Everybody wants to rule the world
Extraordinary way
Eye in the Sky -
Face to Face
Falling from Grace
Fame
Far from Everything
Fat Old Sun - Pink Floyd
Feggari mou - Natassa
Fire - Adele
First Love
Foule Sentimental - A Souson
Foule Sentimental - A S Paradis
Freelove - Depeche Mode
Fresh - Cool and the Gang
Frozen - Madonna
Gee Wiz - Bernadette Peters
Gia tis palies Agapes
Gia poio taksidi beat version KB?
Giati Giati giati
Girl From Ipanema
Girls just wonna have fun
God only Knows
Godfather - Nino Rota
H Aktn
H kardia ponaei otan psnlwnei
H Mousikn
H Mpalanta tou ouri instr - X
H Mpalanta twn Aisthnsewn - X
H prwtn mas nyxta
Hawai 5 0
Hay ma - Hayden
He gives me love - W Houston
Hello - Lionel Richie
High Hopes - Pink Floyd
Hlie mou - Paul
Hlie mou - x
How Deep is your Love
Hugry - Dotan
Hungry Eyes
Hunting High and Low
Hurt - Aquilera
Hurt - Aquilera instr
I'm not scarred
I don't know how to love him
I follow you
I have a dream
I just died in your Arms Tonight
I like Chopin inst - Gazebo
I like Chopin - Gazebo
Ii Mondo - Jimmy Fontana
I'll give her all my love - Mc C
I'll stand by you
I'm gonna follow the sun
I' m not in love - 10cc
I'm singing in the rain - Woman's v
I think of you
I turn to you
I've been waiting for a girl like u
I've had the time of my life
I want to know what love is
If - Pink Floydu
If I had a hammer -
If I never sing another song - DL
In his Kiss - Cher
In Jopardy
In my memory - DJ Tiesto
In New York
In the cold light of day - Placebo
In the Light - Irene Skylakaki
In your Head - Cranberries
Interlude - Siouxie Morrisay
It must have been love
It's a shame
It's a sin
It's five o'clock - Aphrodite's Child
James Bond Theme
Je reviens te chercher
Jeanne
Jeanne B
Julia - Pavlov's Dog
Jungle - Emma Louise
Just an Illusion - Imagination
Just Hold Me - Maria Mena
Just the way you are
Just the Way you Are Pitch P
Just to let you know - CP
Kainourgio mou Feggari - RK
Karma Police - Radioheads
Kathe knpos
Killing me softly
Kingston Town - UB 40
Kiss me - Six pence none
Kocomo
Komteuei 6
Ksnnerwvei Kurialm
L amour est un oiseau rebel - C
L ete Indian
La Bambola - Patty Pravo
La Isla Bonita - M
La Passionnen - Chris Rea
La pettite fills de la mer - Vangelis
Lacrimosa
Largo - Handel
Le Vent Le Cri - Morricone
Learning to Fly
Let the Sky Fall - Adele
Let's do it - Eartha Kit?
Let's Talk About Me - TAPP
Listen to your Heart
Listen to the Radio - The Corrs
Looking for the sun
Love - Nat King Cole
Love is in the air
Love love love - Melina Feat
Love me again - John Newman
Love me like you do - E G
Love's Theme - Barry White
Love Story / Lai
Love Story / Momsieur Minimal
Lousifer - TAPP
Listen to your Heart
Litanie de Saints - Dr John
Live to tell
Live to tell inst
Love to love - Tina Charles
Mal - Christophe
Mammagama - TAP
Man with a harmonica - Morricone
Maybe
Maria - Bernstein
Maria Magdalena
Masterpiece - Gazebo
Memories
Mes autnv tn barka
Mes autn istrumental
Methuse Apopse - Poulopoulos
Methusmevn Politeia
Mia Polln Magikn
Midnight Express
Milk
Mnv Argnseis - Plessas - Asteria
Moi Lolita - Alizee
Moments in time - Anne Dudley
Monaco
Moonlight Shadow - Mike Oldfield
Moonlight Sonnata - Beethoven
Moonriver - Audrey
Music to watch girls by-A Williams
My armiion lovers
My baby just cares for me
My Heart will go on
My Love - Kovacs
My Sweet Lord
Myrtia
Na Balw ta Metakswta
Never let me down
New York - Sinatra
Nights In White Satin - M B
Nikita - Elton John
Nocturne
Nostalgia - Yianni
Nothing Else Matters
O glaros
Ode to my Family - The Cranb...
Oh mon Amour
Old n Wise - TAPP
On the Beach - Chris Rea
One and one
Only Love - Mousxouri
Only Love - U2
Ordinary day
Orinoco Flow
Otan erxontai ta sunefa
Oxygene - Jarre
Pame gia upno Katerima
Parka con me
Phantom of the Opera
Piano man - Billy Joel
Pink Pamther' s Theme
Poor Man' s Moody Blues - BJH
Posa kalikairia
Prelude in C - Bach
Premiers Symptoms
Prwtn Fora
Pyrotechnimata - Paparizou
Quantaramera
Resurrection - PPK
Russian Roulette - Rihana
S agape - loufa kai paralagn
S agapw - Xatzigiannis
S anazntw - Spanos - Dnmntriadn
S' anazntw instr - Spanos
Sade
Salty Dog
San me koitas - Spanos
San me koitas instr - Spanos
Sapore di sale - Gino Paoli
Save a Prayer - DD
Save me - Morrandi
Say it right
Say Something
Secret Garden
See you again - Wiz Khalifa
Self Control
She's a maniac
She's like the Wind
Sleeping Satelite - Y Archer
Snmera - Parios
Something Stupid
Something Stupid
Somewhere over the rainbow-Ray
Soop Soop song
Soothing satelite
Souvenir - OMD
Spending my time
Stalia stalia - Marinela
Stairway to Heaven
Stepping Stone
Stop in the name of love
Stop killing time
Stous 5 anemous
Summer moved on - Aha
Summer wine
Sweet Harmony - Beloved
Sudenly
Supergirl
Supertwister - Camel
Susan - Leonard Cohen
Sweet Movie - X
Symphony 5 Mahler
Symphony 40
T' Asteri tou Boria
Ta paidia tou Peiraia
Take my breath away
Take on me
Tell me Lies
Tha me egw - Gelsomina
Tha s agapw - Spanos
Thalassa - Spanoudakis
That's how string my love is - Ottis
The 4 seasons - Vivaldi
The belly of the Architect
The Chartiots of Fire - Vangelis
The Captain of her Heart
The girl from Ipanema
The Heart asks pleasure first
The Great Gig in the Sky
The lady in red piano
The Look of Love
The Night - Valerie Dore
The Power of Love - FGH
The sea - Markopoulos
The sun always shines
The Year of the Cat
The winner takes it all
This is the Lufe
This used to be my playground
Ti Amo - Tozzi
Ti nai auto pou to lene agapn - SL
Time - TAPP
Time of my Life
Tns Agapns Maxairia
To Agkistri 1976 - Hatzinasios
To France - Mike Oldfield
To Get Lucky - Daft Punk
To Have and not to Hold - M
To Kalokairaki - Fatme
To know him is to love him
To Mustiko - V Leandros
Tonight I celebrate my love
Tosa Kalikairia
Trava mpros
Trouble
Turn Away
Undress me now
Us and them
Vailamos - Enrique Inglesias
Veras - Madonna
Virgin suicide
Viva Forever - Spice Girls
Viva la vida - Coldplay
Vocalise - Orch ver Rachmaninov
Voyage Voyage
Wake from your sleep - Radiohea
Walk on By -  Dionna Warwick?
Wasting my young years
We are the people
We could have it all - Adele
What a Feeling
When I fall I'm love
Whenever whatever - Chakira
Whiter shade of pale
Why.do all things come to an end
Wild is the wind - David Bowie
Wild Rose
Woman - N Cherry
Wonderful life - Hurts
Yesterday when I was young - AW
You - Weddimg Version
You don't own me
You'll be Mine
You'll see - Madonna
You're No Good - Betty Everett
You make it easy -Air
You must ve been kissing a fool


Older version

7 Seconds Away - YN NC
A woman in love - B.Streisand
Abra Cadabra
Acapuclo Nights
Adagio Albinoni
Adagio Barber
Africa
Again again again
Against all Odds
Agnus Dei - Rossini
Air Bach
Air Bach Lousier
Alive and Kicking
All night long
All night Long instr
Alone
Always Somewhere
Amore Mio
An einai n agapn amartia
An thumntheis t oneiro mou
Angels
Animal Instinct
Another Brick in the Wall - PF
Any Better
Apopse se thelw
Aqualung
Aquarious
Ave Maria - Celibe Dion
Bad Boy
Bals twn xamenwn o - X
Beautiful Things
Ben - Michael Jackson
Big in Japan
Born to be Alive -
Boys just wonna have sex
Breath - Pink Floyd
Brexei pali apopse poul
Brexei pali apopse
Brothers in Atms
California Dreamung
Californian Girls
Canon in D - Pachebel
Careless Wisper Inst - G Michael
Careless Wisper - G Michael
Karma Police - Radioheads
Cherish the Love
Chi Mai - Moreicone
Cinderela - Martineli
Clocks
Close to you - Carpenters
Come into my life
Concerto Correli
Concerto in F - Mptzart
Concerto no 2 Rachmaninov Ada
Constant Craving
Crash instrumental - J P
Crash - Jennifer Paige
Societys Child -
Diamonds Are Forever
Don't you Forget about me
Do you know - Diamna Ross
Dream On
Dreams Tge Cranberries
Dust in the Wind
Dws mou t athanato nero
Eagle - Abba
Eklapsa Xthes
Eleonor Rigby
Ena kalimairi
Ena kalokairi instr
Ena Prwino - Xarxakos
Endless Love
Enjoy the silence
Esu kai Egw
Et si tu n existais pas
Ete - Amelie
Eternal Flame
Eveybody Hurts - Corrs
Eye in the Sky -
Fame
Far from Everything
Fat Old Sun
Fire - Adele
First Love
Foule Sentimental - A Souson
Foule Sentimental - A S Paradis
Freelove - Depeche Mode
Fresh - Cool and the Gang
Frozen - Madonna
Gia tis palies Agapes
Giati Giati giati
Girls just wonna have fun
God only Knows
H Aktn
H Mousikn
H Mpalanta tou ouri instr - X
H Mpalanta twn Aisthnsewn - X
H prwtn mas nyxta
Hawai 5 0
He gives me love - W Houston
Hello
High Hopes - Pink Floyd
Hlie mou - Paul
Hlie mou - x
How Deep is your Love
Hungry Eyes
I'm not scarred
I don't know how to love him
I have a dream
I just died in your Arms Tonight
I like Chopin inst - Gazebo
I like Chopin - Gazebo
I'll stand by you
I' m not in love - 10cc
I think of you
I turn to you
I've been waiting for a girl like u
I've had the time of my life
I want to know what love is
If - Pink Floyd
If I never sing another song - DL
Illusion - Imagination
In Jopardy
In my memory
In New York
Interlude - Siouxie Morrisay
It must have been love
It's a sin
James Bond Theme
Je reviens te chercher
Jeanne
Jeanne B
Julia
Just Hold Me
Just the way you are
Just the Way you Are Pitch P
Just to let you know
Killing me softly
Kocomo
Komteuei 6
Ksnnerwvei Kurialm
L amour est un oiseau rebel
La Isla Bonita - M
La Passionnen - Chris Rea
Lacrimosa
Le Vent Le Cri - Morricone
Learning to Fly
Les Choristes
Let's Talk About Me - TAPP
Listen to your Heart
Listen to the Radio - The Corrs
Looking for the sun
Love is in the air
Love's Theme - B.White
Love Story
Lousifer - TAPP
Listen to your Heart
Litanie de Saints
Live to tell
Live to tell inst
Mal - Christophe
Mammagama - TAPP
Maybe
Maria - Bernstein
Maria Magdalena
Masterpiece - Gazebo
Memories
Methuse Apopse - Poulopoulos
Methusmevn Politeia
Mia Polln Magikn
Midnight Express
Mnv Argnseis
Moi Lolita - Alizee
Monaco
Moonlight Shadow - Mike Oldfield
Moonlight Sonnata - Beethoven
Moonriver - Audrey
My armiion lovers
My Heart will go on
My Love - Kovacs
My Sweet Lord
Na Balw ta Metakswta
Never let me down
Nights In White Satin - M B
Nikita - Elton John
Nocturne
Nostalgia - Yianni
Oh mon Amour
Old n Wise
On the Beach - Chris Rea
Only Love - Mousxouri
Only Love - U2
Ordinary day
Orinoco Flow
Oxygene - Jarre
Parka con me
Phantom of the Opera
Pink Pamther' s Theme
Poor Man' s Moody Blues - BJH
Prelude in C - Bach
Premiers Symptoms
Prwtn Fora
Quantaramera
Resurrection
Russian Roulette - Rihana
S agape - loufa kai paralagn
S agapw - Xatzigiannis
Salty Dog
Save a Prayer
Save me - Morrandi
Say it right
Secret Garden
Self Control
She's a maniac
She's like the Wind
Something Stupid
Something Stupid
Soop Soop song
Soothing satelite
Souvenir - OMD
Spending my time
Stairway to Heaven
Stepping Stone
Stop in the name of love
Sweet Harmony - Beloved
Sudenly
Supertwister - Camel
Susan - Leonard Cohen
Stous 5 Anemous
Sweet Movie - X
Symphony 5 Mahler
Symphony 40
T' Asteri tou Boria
Tell me Lies
Tha s agapw - Spanos
The 4 seasons - Vivaldi
The Chartiots of Fire - Vangelis
The Captain of her Heart
The girl from Ipanema
The Great Gig in the Sky
The lady in red piano
The Look of Love
The Power of Love - FGH
The Year of the Cat
The winner takes it all
This is the Lufe
Time - TAPP
Tbs Agapns Maxairia
To Agkistri - Xatzinasios
To France - Mike Oldfield
To Get Lucky - Daft Punk
To Have and not to Hold - M
To Kalokairaki - Fatme
To know him is to love him
To Mustiko - V Leandros
Tonight I celebrate my love
Tosa Kalikairia
Trouble
Turn Away
Undress me now
Us and them
Veras - Madonna
Virgin suicide
Viva Forever - Spice Girls
Viva la vida - Coldplay
Vocalise Orch - Rachmaninov
Wake from your sleep - Radiohea
Walk on By
Wasting my young years
We are the people
When I fall in love
What a Feeling
Whiter shade of pale
Wild Rose
Woman - N Cherry
You piano live
You'll be Mine
You'll see - Madonna
You're beautiful
You make it easy