A battery powered high quality sound reproduction system from phono cartridge to loudspeaker

At your risk. Please take all safety precautions. A battery must be connected in series with a suitable fuse to avoid skin burb in case metal jewelry is worn or avoiding fire hazard.

This system combines previously described Pleiades amplifiers.

It was put up together today for the first time with phono channel out of phase connection corrected and with the RIAA cooking corrections in order to correct overal preamplifier response as described on previous posts.

Preamplifier and power amplifier are operation in class A (electrons flowing all the time, even when there is no music playing).

Total number of transistors used for each channel is 4, 3 K117 JFETS for the preamp operating in low gain with local feedback (source resistors unbypassed) and one 2N3053 on very small heatsink for the power amplifier with zero negative feedback.

Both the phono preamplifier and power amplifier have an output transformer. The power amplifier has a relatively small ferite output transformer with air gap separating the 2 E sections as there is DC current flowing in the primary. Toilet paper is used for the air gap and Siemens Es anre secured together with metal clamps fastened with bolts and nuts.

The DUAL CS-627Q direct drive turntable is battery operated too with same voltage as the power amplifier. 24V from two 1.2Ah powering both turntable and stereo power amplifier.

The hono preamplifier is powered by two 9V batteries.

Power consumption is very low, current consimption is about 20mA for the stereo power amplifier now than the ambient temperature is high, 14mA in the winter. The turntable consumes about 100mA. the phono stereo preamplifier about 2 mA. So total power consumption is somewhat more than 2 Watts.

Power output should be of the order of 100mW yet it sounds surprisingly loud with huge bandwidth and no need was found in today's listening tests for higher volume in a small bedroom with speakers at about 2m or less from listening position.

Signal path:

CD or vinyl records - Sony CD Walkman D-EJ758CK or Dual CS-627Q with original Ortofon cartridge and new stylus - Pleiades 3 K117 phono preamplifier - Pleiades 2N3053 power amplifier - Celestion Ditton 150 loudspeakers - small room with 3 Pleiades membrane (bitumen felt) bass absorbers inside white painting stretched canvas frames of 3 different dimenssions 

CD used is The Year of the Cat - Al Stewart

Records used: Only Love LP - Nana Mouskouri

                        Brothers in Arms LP- Dire Straits

                        One Day in your Life 7" single - Michael Jackson

                        Take a Look - Natalie Cole double LP

The sound quality was amazing, breathtaking with huge bass, smooth mid and very extended treble about 3 more octaves than listening to YouTube, at least one more octave than listening to CD. About at least one more octave that listeningto other CD systems even very high quality ones yet without the harshness. 

Anbience sounded amazing.

And strings did not sound harsh at any time. This is possibly due to the fact that the passive RIAA filter comes immediately after the low gain 1st stage. Therefore clipping of the extreme content of high frequency due to preemphasis on records is avoided, see previous posts on the Pleiades 3 K117 design.

The whole system was exremely quiet no noise or hiss heard at any time even when volume control is at max and no record is playing.

Very impressive is how exteded treble sounded with no harshness, the deep bass and smooth liquid midrange.

The power amplifier is just one transistor for each channel.

   

Equal Loudness Curves can be translated as Καμπύλες Ισης Ακουστότητας

Ωκεανός - Ναντια Διολιντζή Lyrics, Γιωργος Τσακίρης music, Ocean - Nandia Diolingi, George Chakiris, elements of the song

In B minor.

Bossa nova.

Step down bass.

Bass Code (Bach figured bass notation):

B

A6

G7

F7

modulation to E Dorian

E

E46

Example melody with lyrics:

-   B   D   -            στα - γο           chords   (harmony) B D #F

B  -     -    A           να      πεύ-                    

o   B   ο    -            τω                                                  A  #C #F       

-    -     -    E          βυ-

F   D   B    ο           θί - ζο - μαι                                   G B D #F

-    -     -    Α           στον

-    Β    Β   Β          ω-κε-α                                          #F A #C E

Α    ο    Β   ο          νό σου

.   .    .

-   -   B   A              κρά -τα                                           E G B

B  -   -    A

o  o   B   o                                                                     E A #C

A simple MOSFET power amplifier with just a 12V battery, a potentiometer and resistor for bias, an input coupling capacitor and no output transformer

 

At your risk. It may blow your spekaer if  a protective fuse is not connected in series etc.

Please see previous post on Pleiades K951 amplfier with speaker connected directly to the drain of the MOSFET.

Update on Pleiades K951single MOSFET zero feedback single ended power amplifier

 

At your risk.

Today the bifilar 1:1 output transformer was disconnected from drain and connected to the source. This was done fairly quickly as all connections are done with Wago snap terminal connectors.

Source follwer configuration worked with change with readjustment of bias from the 50K potentiometer in series with 47K  but sensitivity was low as there is no voltage gain.

Signal path:

CD - SONY CD Walkman - Pleiades K951 as source follwer - Marantz Imperial 5C

So power suppling the speaker was low.

The amplifier was remodified to drain follower.

Then the output transformer was removed and the AKAI SR H-44 speaker connected directly to drain instead of a load resistor. This should not blow the speaker if drain currect (which now passes through the voice coil) is kept by suitable bias to up to say 300mA. It worked and sounded nice, but less loud than when using the output transformer due to loss of efficiency.

Betasilk or Betaplast etc

 

At your risk. This is not a medical or dermatologist advice. Betadine cream is not suitable for persons with thyroid problem.

Combining 2 products together to create a new product. 

Hansaplast with Betadine cream.

Hansaplast moistened with Betadine cream applied on skin spots may vanish the spot if applied overnight(s) or during the day. 

Betadine cream softens the spot until it breaks, it disinfects and the Hansaplast tisue absorbs.

Thsi idea comes from adapting my dermatolosgist Yiannis Peros' advice when I had a serious skin infection.

 

Merino Wool t-shirts

At your risk.

One of the best thing bought this year. Black long sleeved.

They are 3 times more expensive than cotton but they last at least 3 times more.

Minerva brand.

They keep you warm in the winter, dry on both seasons.

When the is heavy air conditioning in the summer, you are saved as you are dry before entering the air conditioned environment and you don't feel cold.

Dryness in the key.

And they feel compatible with one's skin.

Πολυκυκλωματιστής 501-Β, electronic construction game Polykyklomatic 501-B

At your risk.

Educational Electronics Laboratory.

It is made in a box similar to Monopoly.

70's, 80's game. 

Springs are used to secure contact to electronic components.

The amplifier does not have an output transformer.

The germanium transistor is directly coupled to the loudspeaker.

Everything operated on a 9V battery.

C1 100nF

C2 2nF

C3 220uF 10V

C4 1.8nF?

C5 40uF 16V

speaker Sanyo PAN  Q GH 8ohm 0.3W

potentiometer: 8.8KOhm

lamp: 14ohm when cold

3 Germanium Transistors, using the diode setting of a digital multimeter they measure:

T1, 9H: BE 0.13V, BC 0.123V

T2, 9o: BE 0.4V, BC 0.142V

T3 7c: BE 0.125V, BC 0.111V

By examining the schematics and internal connections below the springs, the amplifier output stage seems to be an emitter follower capacitor coupled (C3) to the speaker

I fondly remember this game. It gave the opportunity to make my first amplifier. I did not know whether it worked. I did not know how to test it. All I could hear was a click in the small speaker and I thought I had done something wrong.

It all came to life when the radio AM tuner from the bigger game 1002 (102 constructions) was connected and radio could be heard around the room with good quality.

 

Pleiades K951 single N channel MOSFET zero feedback audio power amplifier in class A1

At your risk. Take all safety precautions. A suitable fuse must be in serries with any battery for injury or fire hazard protection.

Today the 2SK951 MOSFET was placed on the big heatsink.

Vb=12V. Output transformer bifilar 1:1 with air gap.

Signal path:

music on CD - SONY D-EJ758CK CD Walkman line out - Pleiades K951 - Marantz Imperial 5-G

It sounded not loud, and when the 1K pot was near maximum the sound started to fade out.

Fortunately before abandoning, on a quick decisive move the Wago connector was opened and the signal was sent bypassing the volume pot directly to the gate terminal through the 560K Philips orange coupling capacitor.

Sound became big and loud indicating a broken potentiometer.

The amplifier sounds very nice with deep bass and extended treble, smooth midrange. Some overload at peaks as the full signal is feeding the gate without attenuation.

Id is 500mA at Vd 12V. So power dissipation 6W. Possible power output 3 Watts?

It seems a suitable MOSFET can do the trick without the need of a step up input transformer.

But the electron tube Pleiades DL94 seems to sound better.

Thanks to Vasilis encouragement the Pleiades single transistor amplifier experiments were not abandoned

At your risk.

After so many failed experiments today the power is ten times what it was last year. About 3 Watts? 

So according to S.S. Stevens law loudness is double.

 

Humans Are Idiots and I Am a Very Good Specimen

 

Can diabetes be prevented or even reversed by eating whole grain food instead of products made with white flour, sweeteners etc

 

At your risk.

This is not a medical or nutritionist advice.

For example by eating whole grain tahini?

Advantages of Electron Tubes (Electronic Valves), (Vacuum Tubes) in audio amplifiers

 At your risk.

1. They are cute.

2. Some of them can glow nicely in the dark, orange or blue.

3. They are small size and low mass as no big and heavy heatsink is needed for an amplifier operating in class A (electrons flowing all the time)

4. They are very low noise. So low noise that you don't hear any hiss on Sinatra voice recorded with a Telefunken U47 microphone having a VF14 electron tube inside it. The noise performance of a whole system is dictated by the first stage. Also Harry Olson chose an electron tube instead of a JFET on his experiment on measuring  the thermal agitation noise of molecules with a ribbon microphone inside an evacuated chamber.

5. They sound great. We know that for more than a hundred years.

6. Triodes are so far the most linear electronic amplifying devices without any feedback or its side effects.

7. They are perhaps the most compact and easy way to experiment with electrons themselves and what they can do in a small glass evacuated envelope.

8. They do not need air blowing fans. They radiate heat effectively as the anode can be at a very high temperature without destruction of the device.

9. They cannot be so small that we can place millions of them in a small area and then wonder why do we waste energy.

10 They have high output impedance forcing us to use an output transformer, possibly the greatest sounding and most linear passive device ever made. Dozens of microphone, console, reel to reel tape recorder, signal transformers on our favorite sounding records.

11 They teach us to be careful with electricity which can be dangerous. For example by applying the military practice of one hand inside the back pocket so that touching circuits with both hands in avoided.

12 They teach us to be careful in handling electronic devices.

13 They can amplify straight line frequency response from DC to Megahertz and much more as they have small input capacitance and no heatsink which can be a high output capacitance.

14 They can operate at very high but also at very small voltage if the inherent negative grid bias by the electron cloud near the cathode is compensated by a few Megohms resistor from low voltage anode to grid.

The Pleiades single Darlington BD650 power amplifier in class A supplied by 12V sounds very nice

 At your risk.

Update to Pleiades IRFS450 zero feedback single ended power amplifier with air gap output transformer

 At your risk.

Today a freshly charged 1.2Ah 12V battery was connected. Still using the 1:1 output transformer.

Playing the song Blue Velvet the sound was not impressive. As if the amp has reduced gain at small signals and increased gain at large ones. Is this because the operating point is at a current less than 500mA?

Back to the Pleiades single Darlington BD650 with approximately 3:1 output transformer the sound is phenomenally better with so deep bass, bandwidth.

Brothers in Arms - Dire Straits

 

Update to the Pleiades IRFS450 single MOSFET zero feedback power amplifier in class A operation

At your risk. Please take all safety precautions. A suitable fuse must be in series with a battery for injury or fire hazard protection. 

It is almost one MOSFET, an output transformer and gate biasing arrangment.

Today the cute little IRFS450 MOSFET was mounted on a big black anodised aluminium heatsink about 20 times the area of the transistor itself.

Vb is 12V from a 1.2Ah lead acid battery.

Bias is created as follows. From Vb a potential devider is created with one 47Kohm resistor in series with a multi turn 50Kohm potentiometer. Bias is taken from the wiper of the potentiomer and directly applied to gate.

1st test with a 100 ohm load resistor. Vd=7V at Vg=3.3V

2nd test with 6R8 load resistor. Vd=7V when Vg=3.3V

3rd test with only the primary of the Pleiades 1:1 output transformer with air gap, connected between Vb and drain. The primary DC resistance is 2.4ohms. For given conditions best sound is when Vg=3.7V.

Signal path:

Brothers is Arms - Dire Straits on vintage compilation CD - SONY D-EJ758CK CD Walkman line out - Pleiades IRFS450 - Marantz Imperial 5-G

Yes it worked and sounded surprisingly nice.

Initaly there was some clipping distortion as no volume control had been connected. A potentiometer should always be connected for ear protection anyway. The nearest potentiometr found on the table was a 220Kohms. It worked attenuating the output of the CD walkman but once there was attenuation there was severe treble cut. Possibly form high impedance feeding the high? gate capacitance.

When poentiometer (which must be changed soon to a low K value) was at max, at the begining of the song which is quiet the sound is phenomenal, bright, clear with great bandwidth.

As bias is increased sound is not getting better. There seems to be voltage drop at the small battery.

Heat sink is running hot.

Things look promising. Thank to Panos for giving me the inspiration to try a MOSFET by letting me know of the Suzan Parker zero feedback schematic.

In Music the bass line or melody line are both one note at the time

 At your risk.

For example listening:

On exaple below Melody is the top line, Bass the bottom line:

Anothe bass example, bass going in octaves:

Another example:

Classic example of just voice and bass at 0:38, True - Spandau Ballet:

The rainbow makes you feel happy

 At your risk.

It can be seen while watering with a hose thirsty plants on a field, while sun rays are scattered by the water expanding beam.

The only Product of Art is Hapiness

 At your risk.

Paraphrasing the quote by Brian Eno.

Beginning of the Pleiades IRFS450 single MOSFET audio power amplifier in class A operation (electrons flowing all the time)

 At your risk.

Possibly the first time experimenting with a MOSFET in the Pleiades lab.

I think it is same to IRF450 on a different case.

It is placed on a relatively small heat sink.

In order to check the MOSFET is in order, a digital mulimeter was used at resistance measurmnet. Drain to source resistance reading was infinite.

But when an exhauted 9V battery giving 5.6V was connected from source to gate, the MOSFET had tuned on and Source to Drain resistance was of the order of 0.3 ohms.

Thia condition was preserved even after removing 5.6V to gate. Gate keeps the charge.

Promising. I am curious how will it sound with an output transformer driving the Marzntz Imperial 5-G loudspeaker, MOSFET driven by the SONY D-EJ758CK line out.

 

Update on the Pleiades derivative of simplified no negative feedback Musical Fidelity A1

 At your risk.

Refering to the original Musical Fidelity A1 schematic.

The idea is to try just a BD135 driving a 2N3055 driving an output transformer and no negative feedback.

A BD139 was used instead, a Mitsubishi 2N3055, a bifilar 1:1 output transformer istead of perhaps a more suitable 2:1 output trasformer. Air gap is made by sticking a layer of 3M scotch invisible tpae on the stacked Es.

Vb is 12V.

BD139 is mounted on a small heatsink. 2N3055 is mounted on a larger audio cassette case size heatsink, black aluminium. It run bare touchable hot at 24V.

4R7, 100 ohms, 300ohms resistors are used as on the Musical Fidelity output stage schematic.

Bias is adjusted by a 220Kohm in series with 1Mohm variable resistor from Vb to the base of BD139.

2N3055 Ic was set to about 400mA.

Signal path:

various CDs, Dire Straits, Barbara Streisand, Year of the Cat - Al Stewart - Sony CD Wlkman line out, Pleiades simplified striped down Musical Fidelity A1 - Marantz Imperial 5-G

It worked, it sounded loud, even louder at Vb=24V, Ic=800mA.

Changing 4R7 to 6R8 made for a somewhat more open sound.

Quick changes are posble thanks to using Wago snap connectors.

But there was lack of treble, as if one or two high octaves were missing.

Going back to such a single 2N3055, the sound so softer, less power output but better sound quality, a bit more treble.

Going back to the Pleiades Darlington BD650. It sounded much more open with extended high frequency bandwidth and deep bass too, as if 2 more high octaves were added. Loudness was between the 2 above extremes.

Why does it sound much better? Is it because there are no resistors around the transistors? Should a BD135 driving a 2N3055 be tried in this way with least possible resistors?

The Darlington BD650 at Vb=12V  sounds great at just Ic=100mA, saving charged battery time.

On a small heatsink it run luke warm.

Moving closer to the spekaer at abot 1m from 3 m the sound is even more impressive.

WHat makes this so simple Darlington amplifier stand out is how alive drums sound, hi-hat sounds for example as if there is a hi-hat inside the room, for example of Sultans of Swing - Dire Straits, or On the Border - Al Stewart.

 

Pleiades 2N2146 single Germanium transistor class A power amplifier

 At your risk.

It worked but there was some lack of treble. If memory is correct there is an earlier post on this.

Pleiades amplifiers stand on a Pile of failed experiments

Borrowing an idea from ribbon microphones to low voltage single ended zero feedback power amplifiers in class A

 At your risk.

The impedance of a ribbon could be for example 0.2 ohms.

It is stepped by an internal to the microphone signal transformer to typically 25 ohms or 200 ohms etc.

If we use a MOSFET for a power amplifier we may choose by suitable bias an operating point of 1A at 1.5V. This could mean an output impedance of 1.5 ohms. We have high current but little voltage in order to drive an 8 Ohm loudspeaker.

But if we can also see things upside down we may use a step up transformer instead of a step down transformer as used on electron tube high impedance amplifiers.

So just a few turns for the primary like on a ribbon microphone. And more turns of less thick wire for the output.

Will it work?

The transformer will be fun to make winding few turns for both windings really. Even the secondary can be of the order of only two hundred turns even if using an air gap to avoid DC saturation on a single ended class A power amplifier.

The power supply could be easy too, just for example a D type 1.5V battery in series with a suitable protective fuse. Just one battery will save from the expense to buy may good quality Bulgin battery holders.

Today at Pleiades labs were found a few IRFS540, IRF222, BUZ54A MOSFETS.

Will it work or sound great?

Girls Just Wonna Have Fun - Cyndi Lauper

 

At your risk.

It was heard today on Easy 97.2 MHz FM radio in Athens, Hellas.

It sounds amazing played on the piano too. Key is F sharp major, so you have all those nice black keys.

The bass code is very interesting, like good Bach's music.

For example from 3:22.

Bass F# with A# C# F#

Bass B with A# D# F# ie B major 7th

Bass C# with A# C# F#

Bass F# with A# C# F#

Bass B with A# D# F#

Bass C# with A# C# D# F#

Bass F# with A# C# F#

(this is from memory there may be mistakes as it was figured out on the piano about an hour ago).

It stands alone very well as only bass and melody played together on the piano, bass which is of course only one note at the time played with left hand and melody which is also one note at the time played with right hand. the intervals are so interesting and out of the ordinary. it is a worthy addition  to the Melody Book.

This music is very close to the Bach instruction to his students figured bass code found at the appendix of the Bach's biography by Spitta.

It is likely that in a few centuries people of the future may regard such songs as the classical music of the 20th century, it may be already happening.

It is interesting to note again that in music bass or melody are by definition one note at the time, just one note.

Nobody can hurt you if you do not want it too. Κανεις δεν μπορεί να σου κάνει κακό αν δεν το θες και εσύ.

At your risk. Με δική σας ευθύνη.

By Lambros.  Λάμπρος.

Lambros had given me the book of philosopher Epictetus called Enchiridion, manual of living. Ο Λάμπρος μου είχε δώσει το βιβλίο του φιλοσόφου Επίκτητου με τίτλο Εγχειρίδιον.

Delay on voice is very important

 At your risk.

For example.

A Woman in Love - Barbara Streisand

The Year of the Cat - Al Stewart

Listening carefully one can realize that together with the direct signal of the vocal there is a delayed in time version added.

This can be done in many ways.

An echo chamber does it automatically as it takes time for sound to travel from the speaker to the microphone inside the sound reflective room.

By the way cylindrical pipes like for example drain pipes standing on floor can make the reverberation sweeter possibly due to diffusion scattering of the ways. If memory is correct having seen photos on the Abbey Road book, the echo chamber i think has such or similar scattering structures.

 

How to create an airgap in an output transformer for single ended power amplifiers?

 At your risk.

The Es can be stacked together. The Is are stacked together.

For example Scotch invisible tape can be placed on top of the Es before placing next to them the Is.

When there is DC current flowing in the winding of a transformer, an airgap can prevent magnetic saturation and even increase incremental inductance/

Further reading.

Magnetic Circuits - M.I.T. 

AI

The classic old MIT textbook on this topic is Magnetic Circuits and Transformers: A First Course for Power and Communication Engineers, written by members of the staff of the Department of Electrical Engineering at the Massachusetts Institute of Technology

Reading the small letters on food or beverage packaging

At your risk.

This is not a medical or nutritionist advice.

For example some beverages contain taurine which as fear as i know is a male hormone and these beverages can be seen to be drunk even by very your women.

Or for example cheap cookies or croissants that may contain hydrogenated palm oil (margarine?) which have a reputation or clogging arteries.

On the other hand I had been told told many years ago that sesame seeds or tahini, (made from sesame seeds) is a very good food that keeps arteries and health in great shape. The oil is good quality naturally produced from the sesame seeds. I still eat tahini, every day, see the Pleiades meal or earlier posts/

Is coffee bought in cafeterias contaminated with egg yolk powder?

 At your risk.

This is not a medical or nutritionist advice.

I do not know.

I heard in public transport that a cafeteria in Athens had been closed down in the past as it was found that they were using egg yolk in order to make the coffee velvety creamy etc.

Deaths for example from heart attack or clogged arteries were experienced in the area before there was an order to check the cafeteria for substances that may increase bad cholesterol. 

Hopefully modern cafeterias...

euroelectron antonis orchestral, choral, piano playlist

 

At your risk.

https://www.youtube.com/@renewablemusic/playlists

Update to Pleiades 2N3053 stereo single ended zero feedback power amplifier in class A operation

 

At your risk.

Class A operation means that electrons flow trough the active device (transistor in this case) all the time.

Here are some updates.

The two 1.2Ah 12V batteries were moved to the smaller bedroom.

Signal path:

Brothers in Arms - Dire Straits on un remastered CD - SonyD-EJ758CK CD Walkman line out - Celestion Ditton 150

Great, amazing sound.

Current for both channels was measured to be 32mA, due to higher temperature in Athens.

By chance only one 12V battery was then connected and the sound was even better, more easy and smoother. Current was just 14mA for both channels.

 

J. S. Bach

 

Allegri

 

and this is the famous version recorded just after Roy Goodman had played football:

J. S. Bach

 

Having the pleasure to meet Thymios today

 At your risk. (This is included on most euroelectron posts).

I had the pleasure to be introduced today by Philippos  at Underflow premises  to Thymios.

We talked about single ended low power electron tune power amplifiers. I told him about the 1920s Harold Arnold (see previous posts) design with just one input transformer, an output transformer, just one electron tube and 3 batteries. It sounds great to use a step up input transformer.

Also on electron tube preamplifiers, see previous post.

Also on full range loudspeakers.

Also on output transformers which may emit sound depending on varnish or no. 

An important advice from him is that the system should portray dynamics, micro dynamics as live music and this is why he likes so much such designs as mentioned above.

I pointed him to the pdf Tubes vs Transistors is there an audible difference by Russel O Hamm.

At the end it was mentioned how an electron tube with heater voltage applied automatically has a negative grid potential without anything else connected to it. This is by electrons approaching the grid or equivalently by electrons leaving the cathode leaving it positive. Therefore the electron tune cannot conduct 9have anode current) at a low plate voltage, say 6V. But if a say 8.2M resistor is connected between plate an grid, the grid becomes less negative and the electron tube can operate very well at say Vb=6V with nice grain and very low noise. The heater voltage can even be reduced with even better results, as the anode current is typically of the order of 100uA. For example a high gm variable EF183 triode connected. See Pleiades V6 microphone low level preamplifier.

Thymios explained how important it is that the frequency band from 200Hz upwards sounds great. If the so important mid band sounds great most of the music is there. A quality where triode electron tubes single ended amplifiers in class A excel.

Updates on Pleiades 3 K117 JFET phono 18V battery powered preamplifier

 At your risk.

At the moment frequency response is affected whether the great Sennheiser HD-580 are connected at the output or not (possibly due to load impedance changing with frequency and the fact that the preamp is a no negative feedback design).

Also the setting of the volume pot affects frequency response. Possibly due to the fact that the load resistors are 100K, 220K and 470K for the potentiometer. Maybe some values will be reduced in redesign of one of the channels. Both channels are still on breadboard but inside an aluminum box.

There is also some 1.5dB peak at say 4KHz.

But the preamp sounds great, effortless, with dynamics, smooth violins.

Possibly due to the fact that all source resistors are un bypassed (no electrolytic capacitor in parallel). Therefore each stage is at low gain. And the passive RIAA network is as close to the input are possible. just after the low gain 1st stage. 

So everything sounds smooth, undistorted, violins with no harshness. This is what was told to Thymios, having the pleasure of meeting such a nice engineer for the first time.

  

1224868 all time views on euroelectron

 

Thank you so much!

AI does the pitch increase trick at each note sung until it sounds correct to the listener's mind

 At your risk.

Rhythm of the Rain - The Cascades

 

The DUAL CL11 dipole full range speaker driven by the Pleiades BD650 12V less than 1 Watt power amplifier in class A

 At your risk.

Signal path:

Barbara Streisand's Guilty CD - Sony CD Walkman line out - Pleiades BD650 single Darlington amplifier - Dual CL 11 - big living room

Amazing sounding speaker. With deep bass, extended treble, sounding so real and sensitive. 

Tried for the first time today with the Pleiades BD650.

Only possible problem may be some king of mid high emphasis, by ear it sounds happening at around 4KHz. If this is the case it may be corrected with an inductor in series and a resistor or capacitor in parallel with said inductor, see older euroelectron posts on equalizing full range speakers

Some nice microphones live with Tony Bennet, K.D. Lang, Amy Winehouse

 At your risk.

Blue Velvet

 At your risk.

Today in Athens there is a kind a heat wave. About one hour ago while walking towards the National Library this song was being played at the outdoors cafe. 

While listening on my way I thought it can be heard how good singers build the note sung by increasing the pitch by glissando after attack until it sounds correct to the listener's mind.

The song was inspired by a woman wearing a blue velvet dress at a party watched  by songwriter Bernie Wayne.

https://en.wikipedia.org/wiki/Blue_Velvet_(song)

 

Ζητείται Ωραία Νότα, Nice Note Wanted

 

Joe Dassin

 

This was recommended to me by my friend Albert, the master tuner.

A few days ago he had tuned the piano for Nick Cave's concert in Athens.

A Pleiades derivative of the great Musical Fidelity A1 class A amplifier

 At your risk.

How would it sound if only the last 2 transistors are used with an output transformer say 2:1 and no negative feedback?

For example single ended with BD135 driving the 2N3055,  and Vb=24V.

Euroelectron playlist on YouTube

At your risk.

https://www.youtube.com/playlist?list=PLpEisBQ5la76mpSBX1IuTnT6iD1ywZCq6

Abrazame - Julio Iglesias

Acapulco Nights - G.J. Lunghi

Annabel - Xarhakos

Bad Boy - Den Harrow

Big in Japan - Alphaville

Cenerentola - Martinelli

Crazy - Patsy Cline

Interlude - Siouxsie, Morrisey

Maria Magdalena - Sandra

Miserere - Alegri, Roy Goodman, SIr Willcocks

Tha s' Agapo - Galani

The Captain of Her Heart - Double

The Hook - Hatzinassios

The Fate of Ophelia - Taylor Swift

The Power of Love - Frankie Goes to Hollywood

Year of the Cat - Al Stewart

My Army of Lovers - Army of Lovers

musicalike playlist name on YouTube has been changed to euroelectron playlist

 At your risk.

On renewablemusic YouTube Channel.

https://www.youtube.com/@renewablemusic

Pleiades BD650 one Darlington transistor power amplifier in single ended Class A

 At your risk. A suitable fuse must be in series with any battery for safety. Protect your ears from high SPL. There is a broadband click sound when turning off the amplifier.

It sounds very nice. Drums sound like the real thing.

Singal path: 

On the Border - Al Stewart (on origianl CD) - Sony CD Walkman line out - Marantz Imperial 5G (one speaker so far)

Power supply is just 12V from a 1.3AH lead acid battery. 

Ic is 120mA. So power output should be less than 1W.

Output hand wound transformer is about 3 to 1. So from an 8 ohm speaker the amp sees about 

8 ohms x 3 x 3= 72 ohms. Air gap is by gluing one layer of scitch invisible tape across the stacked Es.

The transformer used on this prototype is rather big.

Bias is by a resitor from collector to base.

There is a 50uF film wound input capacitor.

And a variable series resistor (rheostat)  connected to base for volume control.

It should be nice making 2 such monoblocks inside a transparent plexiglass box powered by 8 AA batteries in series with a suitable fuse.

Everything is Beautiful, Όλα Είναι Όμορφα

At your risk. Με δική σας ευθύνη.

Γυρνώντας από σπίτια

Με πολύχρωμα απαλά ροζ, πορτοκαλί φώτα

Έχοντας περάσει θαυμάσια

Κατηφορίζεις με το απαλό αεράκι της δροσερής νύχτας

Με τισ μουριές να θυμίζουν 

Απο τη γλύκα που γεύτικες

Που σου έδωσε απλόχερα κάτι που στερήθηκες μικρός

Και νέος μένεις όμορφος

Με απίστευτο ταχίνι ολικής

Κακαό 100% και χουρμάδες βασιλικούς

Δίπλα σου στο μετρό

Κάθεται μια κυρία όμορφη

Με μιά μανώλια στα δύο χέρια

Που μυρίζει αρχή καλοκαιριού

musicalike playlist on renewablemusic - youtube

At your risk.

https://www.youtube.com/playlist?list=PLpEisBQ5la76mpSBX1IuTnT6iD1ywZCq6

Acapulco Nights - G.J. Lunghi

Annabel - Xarhakos

Bad Boy - Den Harrow

Big in Japan - Alphaville

Cenerentola - Martinelli

Crazy - Patsy Cline

Interlude - Siouxsie, Morrisey

Maria Magdalena - Sandra

Tha s' Agapo - Galani

The Captain of Her Heart - Double

The Hook - Hatzinassios

The Fate of Ophelia - Taylor Swift

The Power of Love - Frankie Goes to Hollywood

Year of the Cat - Al Stewart

My Army of Lovers - Army of Lovers

A speaker that repairs the sound field ie acoustics of a room?

 At your risk.

For example taking 4 ply linoleum sheets of 2.5mm thickness each and glueing them together with PVA.

Then mounting a woofer and tweeter. Connecting and inductor in series with woofer in order to reduce mid heaviness and a capacitor in series with resistor in series with tweeter until A Woman in Love - Barbara Streisand sounds like listening to the Sennheiser HD-580 headphones.

Hopefully the panel used as speaker baffle acts also as membrane bass absorber.

Jasmine

 

Nothing smells like Jasmine

An outdoors photographic exhibition

Surrounded by jasmines

I forgot the photos

And concentrated on smelling jasmines

Nothing smells like Jasmine

Definition of Musician?

 At your risk.

A person who can sing or play at least one note correctly.

It seems a musical note have to be increased in pitch after the attack of the note ie on sustain. Otherwise it sounds flat to the listener's brain.

Speaking to one person when giving a lecture or writing a book, paper etc

 At your risk.

It helps to do away with stress, anxiety. You think you play for example music to just one person.

I think I leaned this from BBC producer Malcolm Love when he lectured at the British Council in Athens.

What does this resistor do above transistors, electronic valves or electron tubes, JFETS etc?

At your risk.

It was a mystery to be when being a kid. I was building those amazing sounding simple class A amplifiers but at |I did not know.

Then at Warwick University the great lectures of Dr. Neil Storey showed us that this resistor changes the variable current to variable voltage ie the music signal itself. We learned so much about this load resistor, load lines etc.

Please see also the book Electronics, a systems Approach - Dr. Neil Storey

 

Animals are possibly our contact with Paradise

Playing with vinyl records is like climbing a very high mountain...

 At your risk.

For example the better the preamplifier is made the more information can be extracted and there seems to be no limit...

Matti Otala, Transient Intermodulation Distortion

At your risk.

I fondly remember reading papers by Matti Otala on how a transient (music) can make a feedback amplifier distort 100 per cent until negative feedback has time to arrive at the input leaving the amplifier at the very high open loop gain!  

https://www.diyaudio.com/community/threads/matti-otala-an-amplifier-milestone-dead-or-alive.125541/

On an AES conference in 1973, Dr. Matti Otala presented a paper describing the design of a TIM-free audio amplifier...

Update to Pleiades 3 K117 RIAA battery powered phone preamplifier

 At your risk.

Now that it is inside a nice aluminum box, frequency response tests are being made using an inverse RIAA network by Lipshitz.

There was +3dB at mid bass!

-20dB at 20KHz!

It looks like the high impedance 470K pot loaded by the input capacitance of the JFET creates this high cut.

So almost like cheating the 100 Ohms resistor was changed to 12K.

Now we have -3dB at 20KHz. There is about +1.5dB at 4KHz.

For correcting the mid bass heaviness 15nF was changed to 20nF.

Now mid bass is flat and we have -3dB at 20Hz.

Even before the changes the preamp sounds very good with a feeling of 2 octaves above CDs, YouTube videos etc. After the changes about 3 octaves higher treble sparkle and no bass heaviness.

What I do like about  the sound of this preamplifier is the smoothness of the treble on violins. I think this is achieved by the fact that there is no negative feedback, no active negative feedback filter but a passive instead. So transients will not instantaneously clip (see Matti Otala transient intermodulation distortion papers).

I also like  that each stage is at low gain so there is headroom at the input.

Expanding Time

 At your risk.

Acting as if you have infinite time.

For example acting as if time available for a day is infinite.

Acting now as if you have infinite time available.

Then everything runs smoothly with no hurry, no mistakes, accidents. And at the end of the day it feels like you have done a lot.

By Lambros

Love

On Recording Crazy- Patsy Cline

 At your risk.

https://www.npr.org/2000/09/04/1081575/crazy

Ai replies the microphone may have been the Schoeps M201.

A similar mic schematic can be seen here, so simple:

 https://repforums.prosoundweb.com/index.php?action=dlattach;topic=36988.0;attach=2568;image

Some links on Schoeps microphones.

https://repforums.prosoundweb.com/index.php?topic=36988.0

https://repforums.prosoundweb.com/index.php?topic=36988.0

https://tapeop.com/interviews/115/bradley-studios-quonset-hut-and-nashville-sound-bonus

a photo:

https://digi.countrymusichalloffame.org/digital/collection/photo/id/58757/

Ai reply:

which microphone was used for recording patsy cline?

Patsy Cline's legendary Nashville studio recordings were primarily captured using the Schoeps M201 condenser microphone. [1, 2]

The Primary Studio Microphone

While famous singers of her era frequently used the Neumann U47 or Telefunken U47, producer Owen Bradley chose a different path at the famous Bradley Studios (The Quonset Hut). Photographic archives from the Country Music Hall of Fame and Museum capture Patsy standing in front of this specific German-engineered mic during the sessions that defined the "Nashville Sound". [1, 2, 3, 4]

Key Details About the Setup

• The Microphone Model: The Schoeps M201 (introduced in 1952) was a high-end, small-diaphragm tube condenser microphone. It featured a distinct thin, rectangular extension arm that allowed it to look somewhat like a ribbon microphone from a distance. [1, 2]
• The Sonic Character: The Schoeps M201 was celebrated for its pristine, transparent, and ultra-smooth frequency response. This perfectly complemented Patsy's immense vocal power, rich lower register, and emotional dynamics without pushing her voice into harshness. [1, 2]
• The Room Dynamic: At the Quonset Hut, instruments and backing vocalists (like The Jordanaires) were recorded live together in the same room. The microphone's natural capture allowed Bradley to use minimal processing, relying instead on physical placement to create the warm, haunting depth heard on masterpieces like "Crazy" and "I Fall to Pieces". [1, 2, 3]

If you are interested in vintage studio gear, I can provide more details about how Owen Bradley's Quonset Hut studio was set up, or dive into the recording process behind her signature song, "Crazy."

Historical Photo Archives

digi.countrymusichalloffame.org·digi.countrymusichalloffame.org/digital/collection/photo/id/58757/

Patsy Cline during a session at Bradley Studios - Photographic ...

... microphone seen in the photo is a German-made Schoeps microphone, DAS M201, produced in 1952 ... Patsy Cline during a session at Bradley Studios. Subject, Clin...

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Bradley Studios' Quonset Hut & the Nashville Sound | Tape Op Magazine

Bradley Studios is located in the heart of Music Row in Nashville. Owen and Harold Bradley opened the studio in the 1950s. The studio added the Quonset Hut Studio,

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