How to easily create artificial double tracking

Ingredients:


Your voice.


Your ears.


A few meters of garden hose.


One end is used as microphone.


The other end as earphone.


When you sing you hear the direct acoustic sound of your voice as usual plus the acoustic delayed signsl.


It sounds like two different voices together and it sounds fantastic.


RCA used to make a dekay unit using hose and amplifier inside a large loudspeaker like box. If memory is correct it is described in the Studio Acoustics - Rettinger book.

Anither useful and interesting property of analog sound recording

Is crosstalk.


It must be sounding more natural to our brain.


Reference:


Music Engineering - Richard Brice

Is there a problem with frequency response?

It is usually defined by the bandwidth between -3dB points.


If we have a frequency response to 10KHz this does not mean that 29KHz is not respoduced. It is just at a lower level. It all depends on how abrupt the slope is.


For example our ear-brain may approach a nearly flat frequency response at 92dB sound pressure level.


This does not mean that at 70dB we do not hear high frequency content. It is just that nature has it that at lower levels our hearing is more sensitive to mid range frequencies. For survival purposes? Baby crying in the desert etc.


Reference:


Fletcher - Munson equal loudness curves

Another amazing property of magnetic tape analog sound recording

The higher the recorded level of high frequency content the more the HF response decreases.


This reminds the inverse Fletcher-Munson curves of our brain. And also reminds the singer actor voice effort curves.


It also reminds what an HF disc cutting limiter does. Example the Ortofon STL 631.


And also reminding of the Orban Optimod processing in FM broadcasting. For example the Orban 8000 A.


A great HF content is like a high bias current reducing sensitivity at HF.


References:


Audio tape cassettes - Lely, Missriegler - Philips Technical Review


Orban / Broadcast Optimod FM Model 8000 A Operating Manual


Flat frequency responce from singer's vocal chords to listener's brain, Sound Picture recording and reproducing characteristics - Loye, Morgan - Journal of the society of motion picture engineers

Beethoven is using the missing fundamental trick on Moonlight Sonata

When our brain is presented with 2nd, 3rd, 4th etc harmonics, it creates the fundamental although it is objectively missing.


It is not there but our brain creates it.


Beethoven is taking great advantage of this on Moonlight sonata making the piano sound so bassy it is scary.


For example at a point when the left hand plays C2 G2 C3, a C1 fundamental is synthesized by our brain to our perception.


Reference:


Moonlight Sonata score - Beethoven

How to see the overtones (harmonics) on a string

They come from the stationary waves produced by reflections from the end stationary points of a string.


The 2 dimensional analog could be a filled bathtub with water. Dropping something in causes a wave to expand until it is reflected back by the bathtub structure and so on.


The standing waves or harmonics of a string can be seen by stretching a rubber rope of 3 meters for example. Those used for sewing on cloths.


Two people hold each end.


One of them vibrates his-her hand until a frequency is found that reveals the first pattern. Then if that is the fundamental (the lowest permissible frequency), by doubling the frequency of the oscilation of the hand the second overtone (harmonic but overtone is more correct) is seen. Then at triple frequency the third overtone can be seen.


The energy of the wave is reflected by the human hands holding the string. Those repeated reflections create a looping process, the oscilation itself. And the reaction pulses can be easily felt.


Tensioning the string or shortening it changes the reasonant frequencies as tensioning changes the speed of motion of the mechanical wave inside the string- rubber rope.


Same with musical instruments.


When we play C3 on a piano if we listen carefully we can hear many overtones.


One way to teach ourselves listening fir them is by holding C3 until the sound fully decays.


Then playing C4 for 2 seconds and releasing.


The string of the C3 which is still pressed will vibrate sympathetically to the fundamental of C4 so we can hear C4 being played from the string C3!


When we then play C3 normally your brain can more easily understand that those C3, C4 frequencies co exist. And they make the sound of a single note fuller.


In fact any note, A3 for example having a fundamental frequency of 220Hz contains many overtones called the harmonic series.


A bit higher than 2x220Hz which sounds A4.


A bit higher than 3x220Hz which sounds C4.


A bit higher than 4x 220Hz which sounds A5.


A bit higher than 5x220Hz which sounds C#5


and so on.


In the major scale is derived from the heamonic overtone series. This is why there is a DO RE MI FA SOL LA SI. And from just three notes most music is created.


References:


Musical Acoustics - Donald Hall


Waves - F.S. Crawford Jr - Berkeley Physics Course


Bernstein Harvard Lecture - YouTube

This week South Korea is 2nd on euroelectron visits

France is 1st.


Russia is 3rd.


Then US, China, Sweden, Poland, Greece, Ireland, Germany

Analog simulation of magnetic tape analog sound recording part 11

An inductor of 26mH was connected across the output of the Sony CD Walkman line out 370Ω impedance.


The 26mH Pleiades filter should give an 70μs premphasis.


Signal path setup:


Constant Craving - K.D. Lang CD track - Sony CD Walkman line out - 26mH inductor (Pleiades filter) - (Pleiades V4 powered by 4.8V) - line in of Realistic disco mixer - Sennheiser HD580


The sound was very loud with great treble of good quality reminding of some great tube amplifiers such as Luxman.


There was distortion.


The fact that it was loud is very promising. When using 2 cassette heads with their airgaps joined it was very low.


Using just the Pleiades filter the signal was so loud that the line in instead of mic in input had to be chosen on the Realistic disco mixer.


The most likely component being clipped with this setup is the Pleiades V4 prepreamp. The treble sounded very lively. HF clipping sounded like a live haircut scissor. There was some distortion too on the voice.


A next experiment may involve using smaller inductors to make premphasis curves of much lower time constant. For example stopping increasing treble at 10KHz or even 20KHz.


Another experiment may involve using 2 or 3 E,I only laminations (very small iron crossection). Then winding many turns to make an inductance of 26mH. Hopefully this will reveal the sound of magnetic clipping which is the desired outcome.


Doing the above experiments and then de emphasizing to get back to flat frequency responce. A resistor in series with a capacitor to ground could be used to integrate or high cut (low pass). A potentiometer, a Heathkit capacitor switch box and a test CD may aid a lot. Level can be measured on the Realistic VU meter or by connecting an external VTVM.

A great song to learn music with. Careless Whisper - George Mochael Ενα τραγούδι για να μάθουμε εύκολα μουσική

It is written in D minor.


So all notes are white except B which is B flat.


Όλες οι νοτες ειναι άσπρες εκτός απο το Σι που ειναι ύφεση. Μπορούμε να αυτοσχεδιάζουμε παίζοντας αυτες τις νοτες ακουγοντας μαζι το κοματι.


We may improvise by playing any of these notes while listening to the song at the same time.


Bass is:


D
G
B   (Remember every B is flat)
A


Codes or harmony is written as figured bass:


D       ADF
G7     BbDF
B7     ADF
A7     CEG
And repeating as a loop


Οι συγχορδίες γραμμένες με αριθμούς πανω απο το μπαςο ειναι:


ΡΕ           Δηλαδή ΡΕ μπαςο  και. ΛΑ ΡΕ ΦΑ
ΣΟΛ 7                   ΣΟΛ                 ΣΙb Ρε Φα
ΣΙ7                        ΣΙb                   ΛΑ ΡΕ Φα
ΛΑ7                      ΛΑ                   ΝΤΟ ΜΙ ΣΟΛ


Other musical pieces in D minor:


Stepping Stone - Duffy


Adagio from Oboe concerto in D minor - Marcello, Bach


Reference:


http://normanschmidt.net/scores/bachjs-general_bass_rules.pdf

Οι ιδέες μοιράζονται απο ολη την ανθρωπότητα

Αςφαλως υπάρχουν ιδέες; Υπάρχουν άνθρωποι που τις μοιράζονται και η γεναιοδωρία το ανάστημα τους.

Ideas are to be shared by mankind

A simple melody, The Sun your eyes

In D# minor.


-   -   A   D      The sun
-    -   -    -
-   E   F    E    In your eyes
-    -   -    -
(x3  loop)   F     Is
E   D   C   B     All I e-ver
A   -     D   -      Dream for


Harmony is


D
C6
x3 loop
B7


Demo on (date time code 17072612) TDK SAX60 cassette side B
Setup: piano, male voice - 2x 635a - 2x Pleiades 100Hz - Sony TCD5 Pro II
Sounds bass heavy on voice


Public Domain


Reference:


http://normanschmidt.net/scores/bachjs-general_bass_rules.pdf

The principle of least change in music (laziness) part 2

The least the change of notes form one chord to the next the better and more sophisticated it sounds.


An obvious example is:


Vocalise - Rachmaninov
When playing it on the piano using the piano vocal score, most of the fingers stay in the same position playing the same notes while one of the fingers is changing to a different note.
https://m.youtube.com/watch?v=4rkcuhEV9q0


In pop music too.


For example:


Tonight - Reamonn


Also written in the E minor key. (All notes are white except F which is F sharp).


At the chorus the harmony code using Bach's notation or figured bass is:


A9    Oh Ton
D     ight You ki
B7   illed me with your
C7   Smile so
A7   beautiful and
D     Wild so
B     Beautiful and
E     Wild


If one tries to play (on a keyboard instrument for example) those chords it can be clearly heard that the implementation with the least change in nearby notes sounds the best. Sevenths and ninths are prepared for our brain as Bach and Niedt explain.


Reference:


http://normanschmidt.net/scores/bachjs-general_bass_rules.pdf

An Amazing Website on Audio Engineering History

http://www.aes.org/aeshc/

A Great history of recording studios paper written by the master himself, Bill Putnam

http://www.aes.org/aeshc/pdf/putnam_history-of-recording-studios.pdf


This paper was found at the fantastic AES site:


http://www.aes.org/aeshc/
Audio Engineering Society Historical Committee

Is Conscience the most important in life? Ειναι η Συνηδητοτητα οτι πιο σημαντικο;

Most important than anything


If we have conscience, we also have


FREEWILL


FAITH


LOVE


HEALTH





Source:


Michalis, Μιχάλης

Some ways to become much more happy

At your in risk. This is not medical advice.


1 stopping eating good that contains vegetable or palm oil (see ingredient's small letters). On the other hand whole grain sesame is possibly the best.


2 stopping fluoride in tooth paste.


3 try making others happy.


4 read the book Enchiridion - Epictetus
https://www.stmarys-ca.edu/sites/default/files/attachments/files/Enchiridion.pdf


5 read How to Stop Worrying and Start Living - Dale Carnegie
http://www.holistickamedicina.sk/kniznica/Dale%20Carnegie%20-%20How%20To%20Stop%20Worrying%20And%20Start%20Living%20.pdf


6 making your hobby your profession


7 early and late daylight on your body

Everything making us happy is worth remembering

Οτι μας κανει χαρούμενους αξίζει να θυμόμαστε

Life is Beautiful

Ενα Μουσείο Ηχογραφηςης The Athens Recording Museum

Θα μπορουςε να ξεκινήσει σε κάποιο χώρο του ΚΠΣΝ;


Να υπάρχουν μηχανήματα ηχογραφισης και αναπαραγωγής καθε δεκαετίας που να λειτουργούν.


Για παραδειγμα.


Αναλογικα μαγνητόφωνα.


Αναλογικα synthesizers.


Μικρόφωνα καθε δεκαετίας.


Να υπάρχει internet radio φανταςτικης ποιότητας που να εκπέμπει τι γινεται σε πραγματικό χρόνο.


Να μπορούν οι επισκέπτες να φεύγουν με ενα ηχογραφημα απο κάποιον απο τους χώρους πρόβας ορχηςτρας η χορωδίας.


Να γίνονται διαγωνισμοί σύνθεσης τραγουδιών.


Να γινεται μετά ενορχήστρωση η παραγωγή.


Να ηχογραφηθούν τραγούδια τοςο ομορφα που να ανοίγει το ραδιόφωνο ακροατής εξωτερικού και μενει με ανοιχτό το στόμα απο μια τοςο πανέμορφα ηχογραφημένη φωνή.


Να γίνει τοςο γνωστό το ΨιΨιν (ετςι το ονομάζει χαϊδευτικά η γάτα Κανελινα) που να έρχονται απο το εξωτερικό στην Ελλάδα για να ηχογραφήσουν.


Η Κανελινα λέει αφου το Back to Black - Amy Winehouse ηχογραφήθηκε με το μικρόφωνο κορδέλας (ribbon microphone) του 1940, μάρκα RCA μοντέλο 77DX (ίδιο με αυτο που εχει ο Larry King στο desk του;) μπορούμε να κανουμε τα παντα.


Πηγές:


https://m.youtube.com/watch?v=2NVvzRt8fTs


http://www.coutant.org/rca77dx/

Πως να ηχογραφήσεις δυνατά και πλούσια, φωνή η φωνητικά

Με δικη σας ευθύνη.


Στο διπλανό euroelectron post σχετικά με iPad και high volume vocals.

How to create high volume vocals on iPad

At your own risk.


70's mono cassette recorders can do many things that modern equipment can't, like instantaneous peak limiting (analog recorders in general can do this) etc.


Another thing that those mono cassette recorders can do is playing with their speaker the original signal in real time. If one is recording with a microphone and is not careful feedback can occur as in a live concert. And if rec had been been pressed the feedback sound is recorded too.


Positive feedback may not lead to oscilation if the volume is reduced but it's beautiful effect can now be heard. It was an important ingredient of the Wall of Sound - Phil Spector.


When a microphone prepreamp is connected to the iPad's headphone-mic socket unfortunately the iPad speaker is disabled.


The way round this is to connect a speaker to the headphone socket and enable the monitoring option.


It will not sound very loud but it may be adequate and it may be decided not to connect an external power amplifier or connecting a high quality class A (electrons flowing in the electronic amplifying device all the time) amplifier. A single ended class A electron tube or transistor amplifier for example using just one electron tube or one transistor.


As we sing to the mic because of the digital circuitry there is a delay of a few milliseconds for the sound to appear to the speaker. There are also a few milliseconds for the acoustic signal from the speaker to come back to the microphone (due to the finite speed of sound).


If we record in a live area there is reverb fed back. In fact it is echo room or echo chamber reverb.


And the send to reverb is delayed as explained above.


And once the reverb picked by the mic comes afterwards out of the speaker it is acoustically fed back to the reverb chamber.


With digital latency delay again.


This is what Phil Spector was doing.


Delaying what was going to the chamber by analog tape delay. And the output from the chamber back to the tape delay back to the chamber creating a loop. The feedback was controlled before oscillation occurred. In our case the volume control of the iPad should control this.


One can play with microphone speaker distance, indoors or outdoors etc.


A setup could be as follows:


Omnidirectional moving coil mic such as Beyer M55 or Sony F-96 - Pleiades K117 cable prepreamp - iPad - Garagband - a full range speaker connected to the other pins of the headphone socket (bridging stereo to mono) - the recoding room - acoustic sound back to microphone


There is artificial double tracking involved (ADT). The microphone hears you singing and at a few milliseconds later it hears you as processed by the room and the rest of the setup.


Reference:


http://tapeop.com/interviews/64/bones-howe/

How to create ADT, artificial double tracking on iPad in real time

On the nearby euroelectron post on iPad.

Using latency to advantage, for example ADT

On the nearby euroelectron post on iPad.

A very important website with Ampex information

www.recordist.com


By Howard Saner

Another way to apply passive tape playback de emphasis

 It is on the Ampex 600 schematic.


At the anode of the first stage a capacitor in series with a variable resistor is connected to ground. Very simple circuit, it should sound great.


The variable resistor should change the time constant for calibration.


Reference:


Ampex 600 schematic

Beginning this week United States is now second and then Russia on euroelectron visits

France still first.

Analog simulation of magnetic tape analog sound recording part 10

This part is about connecting just an inductor or a transformer at the line output of a Sony CD Walkman and thereby create a 70μs recording characteristic at this line output. (Ie rising output across the inductor at 6dB per octave until the frequency corresponding to 70μs ie 1:70:2:3.17 or 2.27KHz).


Calculation of primary inductance.


Assuming the line out output impedance is 370Ω.


If the wanted time constant is 70μs so as to simulate reel to reel 1/4in 7.5ips then


Since T=L/R


L=TR ie inductance is time constant times output impedance


Therefore


L=70μs x 370Ω       or


L=26mH


So firstly will be connected a Pleiades filter of 26mH, just an 26mH inductor in parallel to get an idea of how it sounds or corresponding measurements taken by playing a test CD with sine tones of constsnt amplitude.


Can the simulation be done with just one coil? Or an autotransformer?
It may be possible since on previous exoeriments inductors or transformers were deliberately overloaded with large sinewave input signals and the sound was similar in harmonic production.


But stepping up the signal that will go to the instantaneous reproduction amplifier by an auto transformer or a transformer may have the advantage of leading to even better signsl to noise ratio.


So the above process (stepping up) should simulate the playback head step up transformer too. The high signal will help to achieve low noise and possibly leading to de emphasis be done passively. For example with a series resistor and then a capacitor shunt to ground. Another resistor in series with the shunt capacitor should stop the high cut action (integration) at a frequency corresponding to 70μs ie 2.27KHz, -3dB turnover point.






L=26mH

Analog simulation of analog magnetic tape sound recording part 9

How would a transformer sound if wound on a chrome type II cassette spool used as a tape wound core?


Or just used as an inductor connected across a signsl output (Pleiades filter). For example across a microphone output. Just an inductir can be thought off as a recording and playback coil at the same time. Since the varying magnetic flux induces back voltage to itself, self inductance.


Like a mass. We apply tension ie force to a mass. It accelerates and then when when we try to change its kinetic condition it reacts sending back force to us.


Is this the reason why inertial mass and weight causing mass are the same as observed by Einstein at the theory of relativity?


A toroidal transfomer.


It is nice that the layers are insulated for eddy currents by the plastic base of the tape.

Is a portable Single Ended class A electron tube power amplifier possible?

This is a next part on Pleiades electron tube power amplifiers.


Not really portable since the output transformers might still be heavy.


It may be possible with 5x 9V Bulgin battery holders secured in the chassis. And 5 Bulgin 1.2V AA battery holders. Rechargeable batteries may be used. In this way very pure 47V and 6.3V are possible.


If EF183 electron tubes are used...


It may be possible to draw 20mA from the cathode. Do cathodes sound better when near saturated by taking most of the elecyrins they can supply? This may be a similar idea to underheating the cathodes (see Pleiades V series pre preamplifiers). But this time the cathodes are normally heated and the cathode current is increased to its limits for the particular 6.3V heating.


The very high anode to grid resistor trick may prove useful for increasing the current at low voltage conditions.


The EF183 electron tube may have an internal resistance of 2.5KΩ? at Va=47V, Ia=20mA.


50V x 0.020A gives 1 Watt anode desipation. This gives a theoretical 500mW output? It should sound loud enough because of the way electron tubes produce harmonics, see Russel O. Hamm reference.


So it may be possible to have a great sounding 2x 500mW electron tube power amplifier operating in class A (electrons flowing all the time).


If input sensitivity is not enough an input transformer may be added.


Cathode may be tried to be connected to ground. So a very high Megohm impedance resistor could be used for bias either from grid to ground or anode to ground. If it is not possible then the schematic of the Neumann U47 microphone could be referred too again for inspiration.


The Pleiades power amplifier may use only one electron tube per channel.


One or 2 transformers. 1 resistor, 1 capacitor. And just a few batteries.


An operating battery time of 7 hours may be possible.


The schematic should be very similar or almost identical to the Pleiades V6 pre pre amplifier.


References:


Neumann U47 schematic


Pleiades V6 schematic


On preserving the transconductance of electron tubes at an anode potential as low as 3 volts - euroelectron


Tubes vs Transistors, Is there an Audible Differnece? - Russel O. Hamm - Journal of the Audio Engineering Society

An very interesting site with one electron tube RIAA schematics

Is the www.tube-classics.de website.


Feeding back from anode to the grid of the same electron tube should be a great way for de emphasis. It can also be seen on the EMI BTR2 playback amplifier where the 6dB per octave low pass filtering de emphasis is done by a series resistor capacitor combination from the front end tube anode to its grid. Part of the circuit is the input transformer of the reproducing head. One of the best tape recorders of all time used by EMI at its studios around the world. We can tell the quality sound from the 50s? 60s? recordings we all know.


Another interesting circuit of RIAA de emphasis for MM cartridges with feedback form the anode of the front end tube to its grid can be found on the VTL book.


References:


E.M.I. Professional Tape Recorder Model BTR/2AM and BTR/2AMR Instruction Manual


The Vacuum Tube Logic Book - David Manley - VTL

Analog simulation of analog magnetic tape recording experiments part 8

The Sony TCA-11 test cassette with cable was inserted on a Tascam Porta 03.


The signal was taken directly (with cable alligator clips) from the Tascam head (the head not disconnected from Tascam).


The Sony cassette was connected to the Sony CD player Walkman. The Constant Craving - K D Lang song was played on CD and it did not sound nice as expected. No bass, no treble. This is the signal coming out of a cassette playback head when tape runs as slow before EQ been applied.


Signal path, setup.


Constant Craving - K D Lang on CD - Sony Walkman CD line out - Sony TCA-11 car cassette adaptor - Canford 1:14 step up transformer with 400mH primary inductance - Pleiades V4 prepreamp operating at 4.8V - Realistic disco mixer mic input


Then a test CD was played with sinewaves at various frequencies.


Watching the VU meter in the Realistic mixer after adjusting gain for 0VU at 1KHz...


There was no apparent movement of the needle at 20Hz. Movement was apparent above 100Hz.


The responce was still increasing up to 1 KHz.


Then after 4KHz it was dropping again.


About 10 dB drop at 20KHz.


It is interesting in the above experiments that the cassette heads do not have to touch when kissing each other. Even at a distance of several millimeters there is magnetic signal coupling but at a low
level. Even before they would touch the signal was almost identical to the full touch condition of the play button fully pressed and engaged.


Reference:


http://www.extra.research.philips.com/hera/people/aarts/_Philips%20Bound%20Archive/PTechReview/PTechReview-31-1970-077.pdf

Γιατι υπάρχει προκατάληψη διαφοροποίησης μεταξύ κλασικής και ποπ μουσικής

Γιατι συμφέρει.


Αυτοί που δεν τρώνε το παραμύθι χρησιμοποιούν ολα τα κόλπα της Μούσας και λάμπουν.


Για παραδειγμα Ordinary Love - U2.
https://m.youtube.com/watch?v=XC3ahd6Di3M


Στοιχειώδης ανάλυση του κομματιού στο διπλανό euroelectron post στα αγγλικά.


Πηγη:


http://normanschmidt.net/scores/bachjs-general_bass_rules.pdf

Why is there a distinction between classical and popular music?

So that great bands like U2 do not buy it and use all the tricks of the Muse and shine. For example nice classical major 7th chords and sharp scales (black keys) and shine.


For example Ordinary Love - U2.
https://m.youtube.com/watch?v=XC3ahd6Di3M


It is written like a cannon, with the bass repeating.


The key is C sharp Dorian.


There are nice major seventh chords. For example when the bass becomes A and the melody or a high part plays G sharp. There is pedal bass at the introduction. Including generalized pedal bass, the guitar playing the same high note while other parts change.


Reference:


http://normanschmidt.net/scores/bachjs-general_bass_rules.pdf

Ενα φανταστικό κοματι για να μάθει κανεις να παιζει μπαςο

Ordinary Love - U2
https://m.youtube.com/watch?v=XC3ahd6Di3M


Χρηςιμοποιει σχεδόν μονο 4 νοτες.


Ρε, Λα, Ντο, Σολ. Με αυτη την επαναλαμβανόμενη σειρά.


Πολλά Ρε, πολλά Λα, πολλά Ντο, πολλά Σολ.


Και παλι απο την αρχή.


Σε σημεια εχει Φα. Και στο μαγικο σημείο Σι ύφεση με μελωδία Λα. Αρα διάστημα μεγάλης έβδομης που τοςο αγαπάει ο Μπαχ και ο Vivaldi και οι αδερφοί Marcello.


Υπάρχει το εξης λάθος σε αυτο το post. Οι νοτες στο κοματι ειναι ενα ημιτονιο πιο κατω απο Otis αναφέρονται. Το κοματι ειναι γραμμένο σε Ντο διεση Δωρικός (τρόπος), C sharp Dorian (mode).


Πηγη:


http://normanschmidt.net/scores/bachjs-general_bass_rules.pdf

A great song for learning bass playing

Ordinary Love - U2


Most of the time the bass plays Re (D), La (A), Do (C), Sol (G) at a repeating loop pattern.


At some points in time there is F in bass. And also at the great moment B flat together with A at some higher part defining an 7 major seventh interval that Bach, Vivaldi and the brothers Marcello so much enjoy.


There is a mistake in this post. The actual,notes of the songs are one semitones lower than stated. The song is written in C sharp Dorian.


Source:


http://normanschmidt.net/scores/bachjs-general_bass_rules.pdf

Another great song with 4 Chords Only

Ordinary Love - U2


https://m.youtube.com/watch?v=XC3ahd6Di3M

A PA system with minimal signal path

It was used outdoors in the country side.


To the astonishment of everyone it sounded great.


It was explained that this is the way it is done in the States so everyone was very willing to proceed.


The roadies were most happy as all they had to carry from the warehouse was a Yamaha console mixing desk with self contained power amps and effects. 2 loudspeakers with their stand. And 2 Shure SM58 or similar microphones with their stand.


Yes they were used as Blumlein pair.


Allan Dower Blumlein is the inventor using 2 ribbon mics at right angles.


The great inventor or innovator of stereo was a great gentleman too. On their first date with his later to be wife he literally took her to the sky. He flew a small plane with her as the only passenger.


2 directional moving coil microphones were used at 90 degrees to each other. So that they could cover the whole stage. They were placed in front of the singers 1-3 feet away from them. This minimizes proximity effect too. The microphones were simultaneously facing away from the conductor. So they were in front of the conductor and possibly what the conductor heard is what the mics were picking up.


The Yamaha mixer had a stereo power amplifier built in.


The loudspeakers were placed in the dead area of each mic. At the console one channel was panned to the left, the other to the right to preserve the sound stage image.


Some reverb or echo was used. But much of space must have come from the acoustic late reflections from trees, rocks or far buildings.


The sound check was started by playing a top quality CD with a known song to EQ the whole system making sure it sounds correct (to listener's brain).


The sound engineer was away and facing the stage near the audience.


It was a joy pulling down the faders on sound check to hear the real acoustic sound. And then pushing them back up to hear the same quality but louder.


Singers would hear themselves. If they needed to sing softer they would just approach the mic pair. They could also hear themselves through the PA. Choir was at the back. Electric bass had its dedicated amplifier. The 2 violin players were playing with everyone as if it were a rehearsal. Everybody could hear each other.


After the concert members of the audience came to congratulate the lazy sound engineer.


References:


The Life and Times of A D Blumlein - Russel Burns - IEE


How to make Friends and Influence your environment - Dale Carnegie

Ένας τρόπος ηχοληψίας συναυλιών χρησιμοποιώντας ελάχιστα μεςα

Στο διπλανό euroelectron post με τίτλο A PA system with minimal signal path.

Ποια ειναι μια καλη μεταφραση για Feedback στην Ηλεκρονικη Μηχανική

Μάλλον οχι ανάδραση.


Μάλλον οχι ανασύζευξη.


Ιςως ανατροφοδότηση.


Feedback ειναι οταν περνούμε μερος της εξόδου ενός ενισχυτή και την τροφοδοτούμε πιςω στην είσοδο. Μπορεί να ειναι θετικο η αρνητικό το feedback.


Αν ειναι αρκετα θετικό μπορεί να δημιουργήσει ταλάντωση. Για παραδειγμα το σφύριγμα που ακούμε οταν το μικρόφωνο ακούει το ίδιο το ηχείο που αναπαράγει αρκετα δυνατά. Τότε αν κάποιος δεν χαμηλωςει την ένταση το σφύριγμα κλειδώνει, παραμένει, ο ενιςχυτης θυμάται την κατάσταση αυτη.


Αυτη ειναι η βάση της μνήμης στα ψηφιακά κυκλώματα. Απο οτι φαινεται για καθε BIT (binary digit) υπάρχει ενα transistor σε κατάσταση ταλάντωσης με ανάδραση; Υπάρχουν και άλλοι τρόποι.


General reference:


Electronics, a systems approach - Neil Storey

A great amplifier for learning how to sing in tune

Is no amplifier.


Or for example connecting speakers where headphones are to be connected.


Or using a milliWatts class A (electrons flowing all the time) power amolofie which is easy to make.


Or listening to so low volume with our amp that when we sing without any effort we hear ourselves as loudly as the reproduced singer.


Pitch perception (how high a note is perceived by our brain) depends not only on frequency but on acoustic intensity too. At low acoustic power levels we might as well perceive the correct pitch and not a flat one.


Would this so low acoustic intensity method help? Is this one of the reason those who really love singing might have perfected themselves? Were they also rehearsing when their parents were sleeping at ultra low volume?


Reference:


Sound and Hearing - S.S. Stevens, Fred Warshofsky - Life science library 

Pour ceux qui attendent le temps s' arrête

For those who wait time is not spent

Is not passing by.


It flows much slower.


For those who wait times stop passing.

Γι' αυτούς που περιμένουν ο χρόνος δεν ξοδεύεται.

Δεν περνάει.


Κυλά πολυ αργά.

The way to get back lost time is stopping worrying

Ο καλύτερος τρόπος να κερδίσεις χαμένο χρόνο ειναι να σταματήσεις να αγωνιας

Making single ended amplifiers sound loud at any volume

If for example a 10W 300B single ended amplifier is played it may sound great and full at 6W.


But if it is used at night, the low output used to not disturb others may be much less than 1/2W.


It is a pity as it is far below the point the amp gets its juice out.


If this is correct then a constant impedance 8Ω resistive attenuator could be connected between amp output and speaker input.


There will not be any change in power consumption. A given class A (electrons flowing all the time) amplifier has the same power consumption no matter how much driven it is. In fact the more it is near its maximum power output the more it cools down. More of the constant power supply is given the the load and less is dessipated as anode electron collision heat in the device. The anode heats up because electrons collide to it and loose their energy to it. Much of this energy is converted to heat by increasing the thermal motion of the anode atoms and other radiation. Perhaps this is why one can see this blue out of this world color outside of the 300B electron tube. Are also soft X rays emitted?


Another way to make the tube sound full and loud at low output but reducing power consumption may be decreasing the anode voltage. So the system is still at its limits but at a low power output. The electron tube should still sound loud as it is producing 2nd harmonics etc, and is instateniously peak limiting as a perfect mastering amplifier with no artifacts.


References:


Applied Electronics - T.S. Gray - M.I.T.


Tubes vs Transistors, is there an audible difference? - Russel O. Hamm - Journal of the Audio Engineering Society

More on the Pleiades single ended class A power amplifiers

If an ordinary 2x5mW headphone Walkman CD amplifier can sound driving loudspeakers beautiful even at 14 meters outdoors in quiet night surroundings...(see a recent previous euroelectron post titled The Best Compressor).


Then a 200mW amplifier would be paradise.


A point is how beautiful, loud and full electron tube amplifiers sound near their signsl overload area.


A very nice sounding EF183 triode connected power amplifier could be made fed with an anode voltage of 12V or above. A resistor or the order of Megohm from anode to grid would increase the anode current and thus lower the output impedance to properly drive the big? output transformers matching to 4 or 8 ohms.


With big transformers designed with air gap it should be possible to go down to 20Hz without the need of negative feedback.


The point is also using just one electron tube per channel (no preamp tube for a pure signal path).


A battery if 12V can supply both heaters of the 2 EF183 in series.


These 12V can supply the anode circuits too.


So there would be no need of bulky and heavy power transformer, tube rectifier, heavy and expensive choke, paper in oil capacitors etc.


If more power than a few great sounding milliwatts is needed then...


Bulgin battery holders (drawer action) can be used for many 9V rechargeable batteries in series. Using batteries seems much simpler than using all the above components.


And there would be absolutely no hum and noise. Just pure silence.


So much silence that the output of the amplifier with nothing connected to its input could be connected to a microphone input and the only sound heard would be the random thermal motion of electrons, ie hiss.


Every time the supply anode voltage is doubled the power should increase four times since Power=(Voltage x Voltage) : Resistance. If by then more voltage signal input is needed to drive the grid of the EF183 then input transformers with say a 1:4 to 1:7 step up ratio could be used. It may be possible to use standard Sowter or Jensen microphone transformers.


Just 5 9V batteries would give 45V. And they can be charged on those Imedion bulk battery chargers. If anode current is 10mA for example and 300mAh batteries are used, they should last less than 30 hours.


This amplifier should be ideal for listening at night. It should sound loud as the tubes would be near their clipping point but the neibours won't mind or notice.


See also the next post on having single ended amplifiers sound loud at any volume.


It is great that so many engineers in Asia know since a long time how great 1 or 2 Watt single ended amplifiers can sound, especially on efficient speakers.

2 nice speakers with ribbon tweeter, Philips MCD708

So far they have been tested with just 5mW directly from a Sony CD Walkman headphone output and they sound great. More on nearby euroelectron posts.


Ribbon tweeters are nice.


Reference:


The best compressor - euroelectron

Can the way laminations are inserted create a magnetic air gap?

For example 7 Es on one direction on top of each other then 7 Es on the other direction.


When using a Pleiades EF183 low voltage battery power amplifier for example. It may be possible inserting the laminations while listening to music in real time for the best bass and overall sound quality.


If doing this at higher voltage much caution and all measures of self protection should be exercised.

The greatest effort of a human being could be not making money

Η μεγαλύτερη προσπάθεια ενός ανθρώπου θα μπορουςε να ειναι να μην βγάλει χρήματα

Το μεγαλύτερο δώρο στη ζωή ειναι να μην πετύχεις, The best gift in life is non success

The Best Compressor

Is our ear.


It can handle an acoustic power ratio of 120dB (12 zeros, 12Bell), or a million million.


In country side at night one can listen satisfactorily to music with just a 2x5mW power amp.


Setup, signal path:


Quiet environment (about 40dB) - Constant Craving - K.D.Lang CD - Sony CD Walkman D-EJ758CK - Philips MCD708 speaker with ribbon tweeter connected to the headphones out of the Sony, with both channels bridged or connected together.


Surprisingly with this setup both bass and treble could be heard.


With a single electron tube or transistor in class A (electrons flowing all the tine) the sound should be amazing. For example the Pleiades transistor power amplifier. Or one EF183 triode connected operating with just 12V and a resistor from anode to grid and an output transformer. 2 for a stereo pair. See other euroelectron posts on the EF183 as power amplifier.

How to easily feel the sound of the frequency responce curve of playback de emphasis curves

At your own risk, protect your ears from accidents.


Noise comes from the random movement of electrons in conductors.


Just like watching the sea water movement noise.


The random movement of electrons is amplified by the preamplifier stages and we can hear it as hiss when we crank up the volume.


Electrons move randomly because they get their energy from our sun. Photons from the sun collide with them giving up their energy.


The frequency spectrum of the noise that out brain analyses reflect the shape of the playback de emphasis curve.


For example on microphone preamplifiers which usually are flat in frequency responce our brain perceives the hiss sound that recording engineers are familiar with.


When we turn up the volume on a moving magnet vinyl cartridge set up the noise we hear reflect the RIAA inverse curve. Increase in bass, decrease in treble.


Similarly on tape reel and cassette recorders. The kind of hiss we hear reveals what is going on.


For example changing the speed setting playback equalization of reel to reel tape recorders. Or switching from normal to type II position on cassette recorders we can hear the change from 120μs de emphasis turnover to 70μs etc.


It's all there.

Connecting a playback cassette head to a microphone preamplifier

The Tascam Porta 03 was used for this experiment.


Without doing any modification or removing any connector from its internal cabling, 2 voltmeter probes were used to get the signal directly from 1 coil of the playback head while it was still connected to Porta 03.


Signal path, setup:


The Sound of Silence (instrumentals) prerecorded cassette, Mercury - 1 coil from the Porta 03 head corresponding to 1 tape track - Canford step up transformer with primary inductance 400mH - Pleiades V4 prepreamplifier powered by 4.8 volts - Realistic disco mixer at mic input - Sennheiser HD580


It is amazing how low the signal from a cassette head is. Is it lower than a moving coil cartridge?


When the fader on the Realistic mixer was full up the VU meters never came to 0 VU.


Had a moving coil microphone be connected the needle would be going like crazy even with soft voice.


The sound lacked low bass, high treble and at midrange the responce was rising. This is expected and it is the reason we apply de emphasis to compensate pre emphasis..


There were no buzz problems as the output from the head is balanced since it is a coil.


Changing from 3 1.2V batteries to 4 for supplying the Pleiades V4 electron tube prepreamp increased the gain. There was still less than 0VU on the realistic mixer.


A higher input transformer step up ratio should give more signal.


Connecting 2 of the head coils in series or in parallel, creating one channel of 2 track stereo for the whole width of the cassette tape should double the voltage output. The other 2 head coils can create the other channel.


Increasing the running speed too should improve many parameters.


The hiss when the pause key was pressed was just like the hiss we are accustomed from top class microphone preamplifiers. But when the moving coils of the microphine capsule is connected hiss is decreased. The cassette head appeared as if it were a 10KΩ equivalent noise resistor which seems very high. Exceeds noise may be a systematic error due to connecting the head with crocodile clip cables which might have picked rf.


It is realized that the hiss we hear when using good cassette players with the pause key pressed reflects the de emphasis playback curve. There is bass noise content and high frequency noise content as expected.

Instapure are very nice tap water filters

A Great Song, Don't You Want Me - The Human League

Many analog synths were playing just one bass line as producer Martin Rushent explains.


Reference:


https://www.soundonsound.com/people/human-league-dont-you-want-me

Pleiades Cassette Format

2 track stereo across the whole magnetic tape width of the compact cassette which is more than half of 1/4in.


7.5ips tape speed?! This will give a C60 cassette a playing time of 7.5 minutes (one direction possible only since full track). Enough for producing a 1 song master.


No Dolby needed.

Excellent papers on tape recording equalization from Magnetic Reference Lab

Such as this:


http://www.mrltapes.com/equaliz.html

Soft starting transistor circuits that have not been used for a long time

At your own risk.


Would the trick of supplying power trough a high series resistor help electrolytic capacitors to reform slowly? Same idea as is done on high voltage electron tube circuits, when a voltage is supplied to the power supply electrolytic capacitors to be reformed through a 1 Megohm resistor and (taking all safety precautions).

Tascam Porta 03 running at turbo speed?

This should be a great machine. In can be read in a forum how good it sounds.


No EQ, bass treble etc like high end amplifiers.


This may be one explanation for its good sound quality, simple signal path, fewer components between source and end product.


How about running it at high speed?


The transport looks very nice. Push buttons operate mechanically. This is an advantage if the motor is supplied by a higher voltage to get higher tape speed without breaking the mechanism! At your own risk. It seems the power connector supplies to the motor before the regulator for the other circuits. So if one is very very careful with little modification the machine could be able to run at very fast speeds.


Then playback and recording characteristics would have to be changed or realigned which means even less hiss.


The 4 separate output from the head are balanced! Like moving coil microphones!


And there is a small connector that disconnects them all.



If 2 pairs are made by connecting for each pair 4 wires to make 2 wires, one could make a good approximation of 2 track cassette. 2 tracks covering most of the width of the tape.


Would it make a great mastering deck?


How would the heads sound with Pleiades electron tube battery preamplifiers. Input transformers could be connected to the heads as is done on EMI BTR2, Ferrograph series 6 and of course moving coil microphones.


Post emphasis would be needed to cut treble. Would 70μs be a suitable time constant for stopping cutting high frequencies?


How about recording with electron tubes at 7.5 ips.


7.5 ips on cassette should correspond to 15 to 30ips on 1/4 reel to reel since the air gap specification on cassette heads is just 2 microns. So at 7.5 ips cassette should go beyond 20KHz without treble boost needed tricks. If a time constant of 35μs is used on cassette?! Just like reel to reel at 15ips. The fact that 2 tracks are used for one channel and the 2 other tracks for the other channel (when using a standard Tascam 4 tack head) may be beneficial for low frequencies because of adjacent leak of tracks carying the same information. The other 2 tracks for the other channel are further away as seen in the Philips reference.


References:


http://www.extra.research.philips.com/hera/people/aarts/_Philips%20Bound%20Archive/PTechReview/PTechReview-31-1970-077.pdf


http://www.mrltapes.com/equaliz.html

While duplicating a cassette magnetic tape records up to 500KHz?

Space science.


The cassette tape during dublication runs at 32 times normal speed?


At more than 1.5 meters per second?


On the amazing paper by the developers.


Reference:


Audio Tape Cassettes - Lely, Missriegler - Philips Technical Review - 1970 - No. 3
http://www.extra.research.philips.com/hera/people/aarts/_Philips%20Bound%20Archive/PTechReview/PTechReview-31-1970-077.pdf

A very interesting inflation (dollar power) calculator

https://www.dollartimes.com/inflation/inflation.php?amount=250&year=1983

The Pleiades CV

It is a normal CV written as a music score a conductor would read and interpret.


The conductor in this case is the HR excecutive.


The elementary idea is on the following euroelectron post.

A way to write a CV with arrow of time Ένας τρόπος να γραφτεί βιογραφικό με το βέλος του χρόνου

At your own risk.


Beware of a contract or anything that has no undo.


Can a CV be written like a quartet score?


For example the 4 part (4 simultaneous musical melody lines) score of Air on G string - Bach
https://m.youtube.com/watch?v=E2j-frfK-yg


Musical scores are brilliant ways to depict events in time (pause is an event to) and of course simultaneous events too.


The arrow of time is from left to right. And in the above example we read four lines at a time!


Our life starts from the left, the date we were born.


Every measure separated by a bar can be every year of our life and anything important that has taken place.


3 sets of four lines may fit to an A4 page so that the CV could be normally read in as few pages as possible.


The set of four lines can be defined for example as follows.


The bass line can be important things in life.


The viola line could be input to our mind. Ie education, influences, seminars etc.


The violin 2 line can be output from our brain. Ie publications, work, ideas etc.


What would be the violin 1 top line?


Advantages of this way of writing a CV is that there is a continuous time axis from left to right. As on any mathematical graph that has the X axis defined as time. The Y axis is what takes place at a particular moment in time.


Duration of events can be shown.


Simultaneous events are very easy to show. They are just one below the other.


You may develop it yourself as your life develops.


The Pleiades CV.


It can be improved by your self.

Είσαι ο άνθρωπος που μ' έμαθε να γελώ

Another interesting property of magnetic tape recording

Print-through.


The spin of electrons containing the recorded information magnetize adjacent layers of tape wound on the spool. In fact it is jealous electrons on the adjacent layer imitating and remembering.


As music is played back it creates a pre echo.


This is something that does not happen nessasarily in nature and the brain keeps very interested.


In a way it is predicting the future. One hears what will happen a fraction of the second before it does.


Our brain likes to be prepared too especially in more complex bass to melody intervals such as 9ths and 7ths, see reference.


Does this property make more difficult music more listenable?


Print through creates a very subtle artificial double tracking effect, low in level and more distant in time.


And as for predicting the future, if memory is correct there is this effect on the Abracadabra - Steve Miller Band. Is the reverb of the electric guitar in time reverse, aparently by reversing the velocity of tape when recording it? Even if not there should be a tape delay to send to reverb according to the book Good Vibrations - Cunningham.


Reference:


http://normanschmidt.net/scores/bachjs-general_bass_rules.pdf

No matter how inexpensive cassette players are, they sound great

Fisher Price kid's toy cassette players...


Very simple circuits, no external EQ, just volume control.

Γιατι οι φωνές τραγουδιών του 60 ακούγονται τοςο φυσικά;

Στο διπλανό euroelectron post στα αγγλικά.

Why do the 60's recordings vocals sound so natural?

There may be many reasons.


The closer we are to the begining of the signal path chain the more important the element is.


So by begining from artist's brain to listener's brain...


1. Artists must have had good mind and physical condition.


2. Songs were well orchestrated to leave frequency space (gap) for the voice. Also the use of non ordinary musical intervals from bass to melody enhances melody. Intervals different from the ordinary 1,3,5 which define major or minor as explained in the Bach - Neidt figured bass code were often used. For example California Girls - Beach Boys using B bass with A major ie B(2,4,7). The song written in the key of B major progresses from B(1,3,5) to B(2,4,7).


3. Rooms had great acoustics. We can see for example at the back cover of Pet Sounds acoustic panels, membranes. They were designed by Bill Putnam. A guess is that they should have had an elastomer material to deflect by vibration as sound strikes. So bass is converted to beat and therefore absorbed. Poly cylindrical diffusers were used for bass absorption and diffusion of sound. Real echo chambers and steel plates were used for reverb. Tape recording reproduction was used for echo.

4. Great microphones of every type were used. For example U47 condenser, RE-15 moving coil, 77DX ribbon. Proximity bass was cut by an internal inductor (coil) connected across the output (Pleiades filter). These inductors were also electromagnetically damping the membrane for plosives and air blasts, (Lens's law in physics).


5. Backing track acoustic intensity input to singer's ears must have been low, helping them to sing in tune. (Pitch perception depends on acoustic intensity of stimulus (Sound and Hearing - S.S. Stevens).


6. Voices were often double tracked.


7. Preamplifiers were made of vacuum electron tubes which have unique overload characteristics and extreme linearity at small signals.


8. Engineers were thinking flat frequency response from singer's vocal chords to listener's brain. Not just from microphine to loudspeaker. They were using passive EQs like the Pultec for this purpose that contain inductors, (coils wound on magnetic ring cores). The material that must had been used is moly permalloy (moly from Molybdenium to get the right amplification factor or quality factor or Q.


9. The signal path was minimal containing a few electron tubes and impedance matching was done with (magnetic material again) signal transformers which have unique overload characteristics.


10. Analogue recorded magnetic tape was used which has unique overload saturation properties.


So we come to 2017 and all those gradual (like nature's non linearity) saturation properties help fit something so tremendous to something so small as is the tiny speaker of our smart phone when our brain enjoys listening to Aquarious - The 5th dimension, You've lost that loving feeling - The Righteous Brothers, or California Dreaming - The Mamas and the Papas on YouTube.


References:


http://normanschmidt.net/scores/bachjs-general_bass_rules.pdf


Sound Picture Recording and Reproducing Characteristics - Loye, Morgan - Journal of the Motion Picture Sound Engineers


Tubes vs Transistors, is there an audible difference? - Russell O. Hamm - JAES


http://vintagewindings.com/products/TransDesign1.html

Photos on microphones and 60's recording sessions can be found by searching Wrecking Crew on google images

An interesting documentary on the Wrecking Crew

https://m.youtube.com/watch?v=GkMDcuA_qTg

Telefunken V72, Pleiades V0, V(-1), Electro-Voice 635a, Sony F-96

This is about finding out how the V72 sounds when generously driven.


The V72 was used ungrounded, it should have been grounded.


The capacitors were softly started to be reformed by sliding the V72 open and connecting 12V in series with 1.7MΩ to a positive power supply capacitor terminal. The voltage across the capacitor did not increase beyond 500mV indicating that either a bleeding shock protecting resistor exists in the circuit or capacitors are bad. Possibly the first is true. The reforming circuit had been left overnight. When mains was supplied it was only for split seconds and then waiting for minutes before re switching on. This gave opportunity to the electrolytic capacitors to reform. After a few hours of repeating the procedure with increasing turning on times and greater turn off periods the V72 was ready for audition.


What an amplifier!


Firstly it was directly connected to 635a.


Signal path, setup:


635a at 1-2in - V72 - Sennheiser HD580


The sound was very clean, beautiful sound, low volume since the V72 was under driven. There were some buzzing problems. Grounding has to be redone as the V72 is used with 2 external XLRs for input and output and perhaps pin 1 is not connected to the metal part of the connector as should be done on chassis XLRs, (see Jensen papers on pin 1 problem).


Next setup:


635a - Pleiades (-1) prepreamp - V72 - 20dB pad - Sennheiser HD580


Sound much louder. Very bright. No s problems. More buzzing problems.


By touching some metal part buzzing disappeared and it was possible to judge the interesting sound quality. The sound was very good quality but very bright.


Next setup:


635a - Canford step up transformer with 400mH primary inductance - Pleiades V0 prepreamp - V72 - 10dB pad - Sennheiser HD580


More full sound, a little bass heavy. Still buzzing . Excellent quality. No s problems. It seems the V72 can be driven more without problem. It's limits may be tried at a later experiment.


Next the Sony F-96 high Z version microphone was connected.


Setup, signal path:


Sony F-96 High at 1 inch - Plaides V0 - V72 - 10dB pad or no pad - Sennheiser HD580


The sound was very clear. Of less volume than 635a. More suitable for high pitched male vocals due to less bass heavy sound. No s problems. No buzzing problems at all.


Then the pad was removed.


Beautiful sound.


More experiments would be useful to find out how the V72 sounds when overdriven.


It is interesting that world class amplifiers do not exhibit any (s) sibilant problem.

Why do electron tubes are instantaneous limiters?

It is not only that electron tubes gently and progressively clip the large parts of the signal while leaving the magic of the average part intact. Much of this can be predicted by examining the characteristic curves of triodes, load resistor lines as the signal peaks approach the anode supply rail etc.


Electron tubes also change their gain acting as compressors or limiters (automatic gain control).


For example the Neumann U47 VF14 circuit.


This was observed by chance around 2000.


By carefully unplugging the capsule assembly it was surprising that there was almost no hiss or noise coming from the VF14 prepreamp output. Low noise and of good quality, of not very high frequency content. This can possibly be explained by the reduction of secondary emission effects by the low anode voltage and also by similar and other effects because of the underheated VF14 cathode. It was also understood that a high grid resistor can contribute very low noise. Many of these principles influenced and inspired many of the Pleiades V series electron tube battery prepreamps.


Coming back to the large signals topic, once the capsule assembly was removed it was time for more experiments.


How does the VF14 prepreamp inside the U47 overload if a high enough sinewave voltage is applied at the capsule input terminals?


A top quality Wein bridge Hewlett Packard 205AG electron tube sinewave generator was used. It's output stage is a pair of 6L6 tubes! And after the output transformer is are 2 brilliant rotary switch constant impedance attenuators in steps of 10 or 1 dB.


Once the VF14 output was connected to a similar quality HP 120B electron tube oscilloscope and input levels adjusted it was time to start increasing the input level to see what will happen to the beautiful crystal clear sinewave at the screen.


As the input was increased to perhaps no matter how high levels the sinewave was there undistorted.


If suddenly the signal was attenuated by 10dB, the sinewave would reduce in amplitude but after a few seconds it would have grown again to the full size of the screen!


This is gain control and if memory is correct the X Y connection mode was also used on the oscilloscope. On the X axis the input signal and on the Y axis the output signal. As the signal was increased the brilliant straight line did I not curve but only its slope was reduced. The more the signal input (after a thresshold) the less the slope.


An explanation of the brilliant effect is the following.


As the signal is increased beyond a threshold voltage the grid starts to be driven positive and draws a tiny current. At the negative part of the input signal current is not drawn. This is a diode effect between cathode and grid.


The rectification of the large input signal (we may now call it the side chain signal) has the effect of charging the grid more negative. When electron tubes operate with more negative bias, anode current drops, transconductance drops and therefore voltage gain drops.


This lasts for a few seconds. If the input is reduced the grid is charged back again to its normal bias. Discharge takes place for those few seconds which is the release time. Thid may be governed by the bias resistor, the grid capacitance etc.


The grid resistor is many megohms.


Would circuits with smaller grid resistor still exhibit this effect but at a much quicker attack and release time? Is this another factor involved in explaining the electron tube transient overload characteristics?


How would a JFET behave if a diode is connected between source and gate to simulate this effect?


The rectification effect of electron tubes is brilliantly explained on how the envelope of the signal changes. In fact in radio engineering the signal is the RF signsl. And the slowly varying side chain signal is the audio signal itself derived from the modulated radio transmiter carrier.


Possibly the most important and clear paper ever written on how electron tubes operste is by the inventor of FM, Edwin Armstrong himself.


This brilliant paper played an important part in explaining how electron tubes are negatively biased internaly by nature. Even before any outside source is applied.


The Pleiades V series preamplifiers can operate at anode voltage of only 3 volts by leaving out any outside negative bias. And by supplying a positive bias high enough to counteract the by nature internal bias while still keeping the grid negative. Still negative but less so with respect to the cathode.


References:


Neumann U47 schematic


The use of multi grid tubes as electrometers - J.R. Prescott - The review of scientific instruments


Open-grid tubes in Low-Level Amplifiers - Robert J. Meyer - Electronics magazine oct. 1944 - Electronics for Engineers - Markus and Zeluff


Operating features of the Audion - Edwin Armstrong


On preserving the transconuctance of electron tubes at anode potential as low as 3 volts - euroelectron blog spot


Tubes vs Transistors, is there an audible difference? - Russel O. Hamm - JAES

In this week additional euroelectron viewers from Iceland. Chile, India

Another way to apply high cut de emphasis

It can be seen on the Italian FBT electron tube Pereonal 1002, 2002 and the transistor mixer Pro.64.


These are fabulous PA systems with tape delay echo running at a non slow speed. The speed can be increased to 7.5ips if a little yellow neoprene cable sleeve tube such as those from Canford is inserted to the capstan.


To the playback heads just after each tape head is a series resistor and then a capacitor (shunt) to ground.


This apparently is the way the rising slope is compensated by reduction at 6dB per octave.


It may prove useful for the analog simulation of analog tape recording Pleiades experiments.


It may also be useful to use directly after a MM record cartridge to de emphasise the high part of the RIAA curve. It may be useful cutting treble from a moving magnet cartridge as soon as possible before they may be clipped by the following amplifying stages. (There is also a schematic on the Altec 1566A electron tube microphone preamplifier. It is included in the operating instructions. It is a passive plug in circuit to do full RIAA de emphasis to get the signal response to flat so that it can be supplied to the front end stage grid. It studied more carefully it may be using feedback too from the output of the first stage.)


A low noise battery powered electron tube Pleiades V series stage with the EF183 may be used in the
above situations.

A way to EQ vocals without EQ

Recording for example a chorus with Beyer M55 HN.


Then double tracking with Sony F-96 high impedance.


By adjusting the volume of the F-96 presence can be added.


The double tracking effect makes the voice sounding much more deep too.


Signal path, setup:


Mic at high Z - Pleiades K117 prepreamp cable (prepreamp inside the connector) - mic 3pin, headphone 3 pin to 4 pin iPad Y adaptor - iPad (GarageBand)


The high impedance has the advantage of making the mic behave like a condenser with high output, the K117 JFET stage then brings the impedance down and is powered directly by iPad just like connecting an electret condenser mic. The quality of sound is phenomenal. These great omni moving coil mics have a step up transformer inside them which damps the membrane for pops and may cut some bass so that the mic sounds correct to our brain. The iPad does this further with its low cut.

Would using a Mu-metal core produce a better bass guitar sound?

Connecting for example a 5H inductor to the bass pickup, (in parallel or shunt).


See also Pleiades V5 on electric bass.


Would Mu-metal produce a great bass sound but with less excessive high frequency content?


Mumetal has the property that after a frequency, it's inductance is decreasing so that the inductive reactance (in ohms) remains content [1].


Reference:


[1] Coil construction and design manual - B.B. Babani

Γιατι η φωνή στις μουςικες παραγωγές του εξωτερικού ακουγεται τοςο πιο γεμάτα, δυνατά, αβίαστα;

Στοιχεια στο διπλανό παραμύθι με την Κανελινα.

Η Κσνελινα ξσνακλαιει

Όλο και πιο πολυ ανακαλύπτουν με την υπομονετική χελώνα οτι το μυστικό για ν'ακουστεί απίστευτη η φωνή πρεπει να ειναι η μεταλλουργία.


Στο εξωτερικό όλοι οι μεγάλοι τραγουδιστές η παραγωγοί χρησιμοποιούν το φίλτρο συχνοτήτων η EQ με το όνομα Pultec (pulse technologies). Τα πηνια απο οτι φαινεται περιεχουν και Μολυβδενιο στα ring magnetic cores.


Επισεις για παραδειγμα οι Beatles, Shirley Bassey, Καζαντζίδης κτλ. χρησιμοποιούσαν κονσόλα EMI η οποία είχε προενισχυτες Telefunken. Aπο οτι φενεται οι προενισχυτες έχουν μετασχηματιστές σήματος φτιαγμένους απο την Haufe στη Γερμανία.


Ολα αυτα οπως και οι σωλήνες ηλεκρονιων η διακριτά τρανζίστορ (ενα ραδιόφωνο αποτελείται απο πολλά τρανζίστορ) κανουν τον ήχο απίστευτα πλούσιο καθώς στα μεγάλα σήματα παράγουν σταδιακά overtones, αρμονικές.


Low order harmonics. 2η που ειναι σχεδόν οκτάβα κσι 3η που ειναι σχεδόν οκτάβα και 5η κτλ.


Ειναι αυτός ο λόγος που οταν ήρθε το Γερμανικό συνεργείο να αντικαταστήσει με ψηφιακές κονσόλες στη ΕΡΤ ήθελαν οπωσδήποτε να πάρουν την αναλογική κονσόλα πιςω;! Μάλλον θα ήταν της Siemens; Αυτη η κονσόλα πρεπει να βρίσκεται ακομη στο studio των θεατρικών εκπομπών.


Πρεπει να ειναι γεμάτη με τέτοιους μετασχηματιστές σήματος.


Ευτυχώς ο τότε διευθυντής ραδιοφωνίας αρνήθηκε να την δώσει.


(Γι' αυτο οι ξένες παραγωγές ακούγονται με τόσες φορες περιςςοτερο όγκο στις φωνές ενώ οι τραγουδιστές τραγουδανε τελείως αβίαστα και σιγα;. Τι κανουν; Χρησιμοποιούν ενα χαμηλού θορύβου προ προενισχυτη για να οδηγούν γεναιοδωρα τα επόμενα στάδια ενίσχυσης; Το μικρόφωνο U47 εμπεριέχει προ προενισχυτη. Τον σωληνα ηλεκρονιων VF14.


Ο σταδιακός τρόπος (καθώς το σημα εισόδου μεγαλώνει) με τον οποιο παράγουν αρμονικές κανουν τον εγκεφαλο να αντιλαμβάνεται ένταση και όγκο. Οπως οταν μια τρομπέτα που παίζεται πιο δυνατά παράγει σταδιακά περισσότερες αρμονικές.


Και ταυτοχρονα επιτυγχάνεται (το ίδιο φαινόμενο) στιγμιαίος ψαλιδισμος κορυφών της κυματομορφης.


Ετςι μπορεί μετά να γίνει ψηφιοποίηση (digital conversion) η ψηφιακή εγγραφή χωρις να τα παίξουν οι A to D converters, μετατροπείς απο αναλογικό σε ψηφιακό σημα.


Ειναι λοιπόν και αυτός ένας σημαντικός λόγος που full αναλογικά ηχογραφημένα κοματια οπως το This girl's in love - Warwick ακούγονται μετά απο μισό αιώνα απίστευτα στο YouTube?


Καθώς οι μαγνητικοί πυρήνες (magnetic cores) γυρω απο τους οποίους ειναι τυλιγμένα τα πηνια των μετασχηματιστών σήματος και φίλτρων υπέρ οδηγούνται με σημα φτάνουν σταδιακά σε μαγνητικό κορεσμό. Οπως η αναλογικα ηχογραφημένη μαγνητοταινία. Οπως οταν ένας σωλήνας ηλεκτρονίων ψαλιδίζει ενα μεγάλο σημα.


Ετςι ο εγκεφαλος αντιλαμβάνεται κατι δυνατό ενώ στην πραγματικότητα η αντικειμενική ενέργεια ειναι σχετικά λίγη.


Η Κανελινα σκούπισε τα δάκρυα της.


Πήγε στην παραλια με την υπομονετική χελώνα. Ήρθε κσι ο γάτος με την πραςινη κορδελα. Η Κανελινα πετάχτηκε απο τη χαρά της.


Και όλοι μαζι με τους σοφούς γλάρους, τους κορμοράνους, τα θαλαςςια ζωάκια μεςα στα κοχύλια τραγουδηςαν κσι χόρεψαν, This girl's in love.


Kάτω απο το φως του Ηλιου που δεν αφηνει καμια σκια στη φωτεινή αλήθεια.


Πηγη:


Tubes vs Transistors, Is there an audible difference? - Russel O. Hamm - JAES

The secret of the music industry?

Is it?


The low distortion near the zero crossing point (around the average of the signal).


Gradual controlled distortion at high level signals.


Both requirements are achieved by analog discrete electron tube or transistor circuits in class A (electrons flowing all the time) or signal transformers,


Reference:


Tube vs transistors, is there an audible deference - Russel O. Hamm - JAES


Applied Electronics - T.S. Gray - MIT
(General amazing reference)

Is the game on metallurgy?

Just like piano steel (with chromium?) strings.


The magnetic material defines how the signs, transformer will overload. Gently or not? So with high overtones or not?

Transformers are Great

Magneticaly Recording and Reproducing in real time.

2 very important teachers at high school

Babis Pantazatos - Mathematics
He could teach Aristotelian logic like no other.


Alekos Soupianos - Physics
He could teach electricity and magnetism like no other.

Pleiades filters simulating recording and reproducing in real time

This may be the simplest simulation.


Just any inductor connected in parallel with the signal.


The signal voltage causes current to flow through the inductor.


Current (electron flow) creates a surrounding magnetic field.


So the varying signal current creates a varying magnetic field. (same as a recording head).


Varying magnetic fields can produce a corresponding voltage in nearby coils or inductors.


So voltage is created on the same inductor, like a reproducing head does.


Since the same inductor is the cause and result, it is called self inductance.


This miracle is done by the magnetic flux flowing inside the magnetic core to which the winding is wound.


If another inductor is wound around this core this is called mutual inductance and we have a transformer.


The core material plays a very important role at it defines how the system behaves at very low signals and how gradual the desired in audio engineering saturation is.


A most important thing to remember, perhaps all electromagnetism in 3 sentences is the following:


Stationary charges create an electric field.


Moving charges create a magnetic field.


Accelerating charges create an electromagnetic wave.


References:


Electromagnetism - Grant, Phillips


The Feynman lectures in physics - Volume II


Engineering Electromagnetics - Hayt


Applied Electromagnetics - Plonus


Electricity and Magnetism - Purcell - Berkely Physics Course


A treatease on Electricity and Magnetism - Maxwell - Dover


Tubes vs Transistors, is there an audible difference - Russel O. Hamm, JAES


Alekos Soupianos Lectures

Ποσο μου αρέσει ο τρόπος που με κανεις να γελώ

Πως φεύγει η Ελλάδα απο την κρίση

Με δικη σας ευθύνη. Δεν αποτελει ιατρική συμβουλή.


Βήμα πρώτο:


Σταματάμε να τρώμε οτι περιεχει φυνικελαιο που εχει τη φήμη οτι βουλώνει τις αρτηριες. Υπάρχει στο φθηνό κέικ, κρουασάν, φρυγανιά, ψωμι του τοστ, φουντουκοπαστα, φυστικοβουτυρο, χωνάκι παγωτού, παγωτό. Για παραδειγμα πολυ υγειηνο ψωμι μπορούμε να αγοράσουμε η να φτιάξουμε με αλεύρι ολικής, Ζέας (που εχει λιγότερη γλουτένη που ειναι λιγο σαν κολα για το μυαλό και το σώμα)  προζύμι και νερό. Μετά βάζουμε αγνό παρθένο ελαιόλαδο, ρίγανη κτλ.


Το φθηνό δεν ειναι καθόλου φθηνό. Το πληρώνει κανεις πολλαπλάσια για ιατρική περίθαλψη.


Και η ψυχική οδύνη ειναι ξανα πολλαπλάσια.


Υγιείς πολίτες μπορούν να κανουν τη διαφορα.


Πηγές:


Εγχειρίδιο - Επικτητος - απαντα εκδόσεις Κάκτος


http://www.brainybetty.com/2007Motivation/Epictetus%20-%20Manual.pdf


Fringe knowledge for beginers - Montalk
https://montalk.net/files/fringeknowledgeWEB.pdf

Συνομωσία της συνωμοσίας, Conspiracy of conspiracy

Με δικη σας ευθύνη.


Υπάρχει η συζήτηση για τα αεροπλάνα που ψεκάζουν για να κρύβονται πολυ πιο καθημερινά πράγματα; Why should we care if airplanes spray or not when most of commercial food contains palm oil which has a reputation of cloging arteries. And our toothpaste contains fluoride which has a reputation of interfering with brain function.


Πχ οτι σχεδόν όλες οι ζύμες στην Ελλάδα φτιάχνονται με φυνικελαιο που εχει τη φήμη οτι βουλώνει τις αρτηριες;


Αναγράφεται το φυνικελαιο και φυτικά λιπαρά στα συςτατικα σχεδόν καθε συσκευασίας (και πολυ σε αυτες που προορίζονται για παιδιά) οπως και κουλουράκια, κέικ, άλειμματα για ψωμι μαργαρίνη κτλ, φουντουκοπαστα, ψωμι του τοστ, τυρόπιτα.


Απο οτι φαινεται για να φτιάξουμε top σφολιάτα πρεπει να την φτιάξουμε μόνοι μας βάζοντας σε για καθένα δίπλωμα φύλου καλής ποιότητας αγελαδινό βούτυρο.


Προσοχή επισεις στο φθόριο κτλ στην οδοντόκρεμα.


Γιατι να ψεκάζουν τα αεροπλάνα οταν υπάρχουν πολυ πιο εύκολοι τρόποι;

Analog simulation of analog tape recording reproduction part 7

It won't be easy.


If something truly portable is to be made...


An omnidirectional microphine such as Beyer M55 or Sony F-96 could be used.


Inside the mic could be the stepping up transformer producing correct frequency responce from artist's brain to listener's brain.


Then a JFET preamplifier stage(s).


Then an interstage transformer made from a very thin magnetic material (small cross sectional area so it can easily saturate while producing the rising 6dB per octave recording characteristic slope).


The secondary of the interstage transformer feeding a few JFET stages. Then frequency selective negative feedback (for example with a capacitor resistor circuit) from the last stage to the first to low cut at 6dB per octave to restore the frequency response to flat while rounding limited peaks. This should hopefully give a nice simulation of very fast running reel to reel tape recording in real time.


Metallurgy seems very important for the transformer ring core.


If all these can fit inside the mic including a buffer JFET stage, then everything can be directly connected to an iPad or mobile phone mic input. Could the mic input power not only the buffer stage but everything else?


Would this be a great solution for an artist wanting to have top natural, loud and alive studio quality by just connecting a mic to a device?





l

Magnetic Tape playback de emphasis is usually done by frequency selective feedback

The signal at the reproducing head should be a very bright signal 6dB per octave rising with frequency.


The playback preamplifier just have a very high gain at low frequencies and low gain at high frequencies.


This is usually done by a frequency selective negative feedback circuit using resistance, capacitance.


For the example on the EMI BTR2 tape recorder the head is connected to an input transformer by a balanced connection. Exactly how moving coil microphones are connected.


The signal is connected to the control grid of a high voltage gain pentode EF37A.


A 0.01 capacitor is connected to the anode.


A 150KΩ resistor is connected in series to the capacitor and its other end to grid. This as explained in the service manual provided the basis -6dB per octave high cut.


Similar feedback ideas from the second electron tube to the first's cathode can be seen on Ferrograph series 6.


Also such feedback circuits are used on RIAA, record playback preamplifiers.


Would it be possible to connect 3 low gain battery powered EF183, anodes operating with 6-12V as on Pleiades V series and feeding from the anode of the last tube to the grid of the first?


Also JFETs could be used.


References:


EMI BTR2 manual


Ferrograph series 6 manual


VTL vacuum tube logic handbook


Tube preamp cookbook - Allen Wright

Wikipedia has interesting articles on Mu-metal, Silicon steel, Permalloy etc

An interesting article on tape heads

http://www.jrfmagnetics.com/tapeheadintro.html

Mumetal has a peculiar property of inductance index starting decreasing after bass frequencies

See also analog simulation of tape recording experiments part 2.


Reference:


Coil Design and Construction Manual - B. B. Babani - page 79 (input and inter valve transformers)

Analog simulation of tape recording part 7 Overloading badly with a modified Jensen Transformer

Around 2008? a Jensen mic input transformer was opened with a thin saw.


The primary turns were reduced to only 69? if memory is correct.


Most laminations were removed to further reduce the primary inductance.


It was in an attempt to create a Sleeping Satelite - Tasmine Archer bright vocal sound with an MD421 black type.


The inductance after the operation is 3.5 - 4mH only giving a very high frequency low cut (Pleiades filter) turnover point.


Then the secondary was connecte through a capacitor to the gate of a K117 JFET in source follower configuration.


Everything in one box with a 2 AA battery holder. This is the Pleiades T1.


Today it was revisited again. Gain was not as high as expected (sometimes the gate is statically charged). Nevertheless the line output of the Sony CD Walkman was connected to the XLR input and a test sinewave tone CD played.


When the female announcer was stating the frequency it was real distortion, but interesting one reminding of cassette overdriven badly.


Interesting sound.


It was of course extremely bright as the frequency rising 6dB per octave slope was not de emphasized by a corresponding high cut filter.


The Jensen transformer as modified is now a very high turn ratio transformer 1:70?. This means it also has a high cut roll off. This may be interesting as it may also simulate the high frequency reduction due the tape loss head gap wavelength - speed effects.


It is uncertain though were was the clipping taking place. The transformer?, the JFET? Or the following preamp? This experiment may be repeated much more slowly with an oscilloscope or signal tracer with adequate headphone pad for ear protection.


Setup, signal path:


Sony CD Walkman line out, Z=370Ω - (Pleiades T1 ie modified Jensen transformer - K117) - Realistic disco mixer at line in input - Sennheiser HD580


Other experiments may include 2 or 3 E laminations from a Canford bought BBC transformer inserted in a small bobbin wound for somewhat greater inductance. It is hoped that a few laminations would simulate the saturation of tape at a small H field or magnetic excitation level.

Overloading Haufe transformers

There is some information here:


https://groupdiy.com/index.php?topic=28563.0


https://groupdiy.com/index.php?topic=17260.0

Sounding to our brain the way the producer's brain intended it is High Fidelity

Analog simulation of analog magnetic tape music recording experiments part 6, reducing magnetic material

Magnetic tape is thin and the material touching the air gap is little,


A useful experiment to get a transformer core to saturate at small levels is to get an ordinary E I or interleaved E lamination signal transformer and start subtracting laminations?



Do Sowter or Jensen transformers use silicon stell laminations? How about BBC specified transformers?


Is Haufe in Germany possibly the best source of cores? Do Telefunken V72s use Haufe cores?


It is a joy staring with a wound bobbin and beginning insetting the E laminations observing the inductsnce increasing when an L meter is connected to the winding terminals.


Hopefully these notes may inspire those interested to do their own exoeriments and discoveries.

Analog simulation of magnetic tape analog recording part 5 DC current in signal transformers

Does feeding a signal transformer with DC current produce an asymmetric saturation waveform ie even harmonics too?


Must it be a low current as DC overdoing the core may create too must distortion.


The production of even harmonics may make the magneticaly saturated sound even nicer,


Is this another reason why Neve preamplifier class A (electrons flowing all the time) output stages (single ended transistor) passing DC current through the output transformer primary sound great? Or for the same reason electron tube single ended class A power amplifiers with no negative feedback?! DC carrying transformers have an air gap in their design to avoid magnetically clipping the core.


The word air gap is also used on magnetic tsoe recording heads. Dies it make performance even more linear at small signal levels?


An interstage transformer may be suitable for analog simulation exoeriments. The DC current passing at the primary and non existent at the secondary will do the coupling without the need of a capacitor. Voltage can be stepped up. And the interstage transformer when constant current fed with respect to frequency can simulate tape recording, reproduction. Constant current can be made by feeding it through a high resistor. The voltage drop at the resistor will give the rising frequency emphasis slope.


The secondary stepping up the signal, may make it high enough to feed the de emphasis (high cut) instateneous playback preamplifier.


Will this sound as good as very very high reel to reel magnetic ape speeds with excellent high frequencies and in general excellent signal conditioning saturating characteristics? Will it increase the average signal without affecting the quality of the music as the best reel recorder or FM Optimod (Orban) processor?

Why analog tape recording has thick bass?

Big bass even when reproduced on a tiny speaker.


Is it the well known psychoacoustic phenomenon of the brain creating the missing fundamental?


The brain creates it if the harmonics are present.


In the past this property was used in electron tube record players, 1960's? The harmonic distortion or production was used to create the missing bass frequencies from relatively small speakers. Emerson E501 record player for example.


The E501 has the preamp electron tube cathode connected to ground. A 10 or 20? Megohm resistor in parallel with a 0.01 capacitor feeds the grid. This may be called grid leak biasing. At peaks a voltage is generated by the rectifying action of the grid. This increased negative bias reduces gain as it is really a side chain compressor voltage. Distortion artifacts must be creating useful clues for the brain to recreate a missing bass from the relatively small full range speaker. Attention when using these players. The mains voltage is used with no isolating transformer?!!! Smokey or potentially smokey resistors should be replaced and the operating unit when should not be left unattended.


Repeating:
Even when the fundamental bass is missing the brain creates from the existence of the harmonics.


Audio transformers and cassette (reel to reel players too?) gently and progressively overload at low frequencies too. This creates harmonics for every harmonic. Intermodulation is apparently less because of the rising in frequency recording characteristic?


If the fundamental and second harmonic is missing can the brain complete the picture?


Ie is it possible missing fundamentals that form a harmonic series to synthesize their missing fundamental in our brain? Ie can a missing fundamental (overtone) when created by our brain create in turn its missing fundamental?


Phycho-acoustics owes so much to S.S. Stevens!

Analog simulation of analog magnetic tape recording using transformers

In fact signal transformers can be considered to be instantaneous magnetic recording playback devices.


The signal is converted to varying magnetic field. The varying magnetic field linking the secondary produces the reproduction signal to the secondary.


Signal transformers are usually constant voltage driven with respect to frequency.


The Pleiades idea is feeding with constant current wrt frequency as is done on reel to reel magnetic recording heads.


And then de emphasise the rising output slope by a low cut filter. It will round off as usual peak limited waveform peaks. As is done on playback head preamplifiers?


Lefteris, long time ago, before 2000? was bringing to attention the fact that transformers playback in real time. Instantaneously. They recreate music.


So naturally fresh.

Is it "distortion" that creates real sound?

Anything that has subtle no linearity at its output as input level is increased creates harmonic "distortion".


Is it this "distortion" that makes something sound so real?


It is created at the same instant the sound is reproduced in analog systems.


And it is distortion no more as...


The goal of recording production, reproduction is not what happens from microphine to loudspeaker but from artist's, producer's brain to listener's brain.


Reference:


Flat frequency responce from vocal chords of actor, singer to listener's brain, Sound picture recording and reproducing characteristics - Loye, Morgan - JSMPE