Analogue Electronics-"Iron in the Soul"

[zoekav]

Attractive colouration for audio processing.

Vintage pro-audio recording and processing equipment is much sought after and can command very high prices in the second hand pro-audio marketplace. One reason for this is that such equipment is said to produce attractive coloration/distortion of audio signals due to components such as transformers and valves present in the signal path and the magnetic tape recording medium. These all introduce small amounts of nonlinear distortion sometimes considered to be attractive for audio signal processing. An example of this being that vintage equipment is sometimes said to give the added quality of ‘warmth’ to an audio signal passing through the unit.

This project will involve an investigation into the nature of distortion and coloration produced by audio transformers, the valve processing units in the studios and magnetic tape. The project will also involve the design and analysis of some simple audio circuits using audio transformers which will aim to emulate some of the audio properties of vintage units. Circuits will be designed and assessed using SPICE simulation and constructed and tested in the lab for distortion. Audio signals processed by the test circuits will be subjectively evaluated by a panel of trained listeners.

I have been looking at designing a simple phono pre amp similar to the Nagra VPS phono pre-amp kind of. any ideas and where i can get free licence circuitry will be appreciated.

Many thanks

 

[cowboybob]

Welcome to ETO, zoekav!

Here's a bunch of them (PREAMPS, AMPS, ETC.). Take your pick... https://diyaudioprojects.com/Schematics/

Tube type anything (especially with transformers) is expensive to build these days. But, I will say, well worth the effort.

Here's some amp kits (stereo and mono. Tubes NOT included): https://www.dynakitparts.com/?gclid=CIXF7siRycYCFQEcaQod9ZcD_w.

 

[audioguru]

I disagree that coloration and distortion are attractive. I like to hear the music, not awful old fashioned circuitry.
Oh, are you talking about Acid Rock or RAP? They are noises, not music. Colored and distorted noise still sounds like noise.

 

[zoekav]

audioguru Thanks for your input, this topic is subjective and I respect your opinion, however I am looking for circuits that have audio transformers, valves and make use of magnetic tapes (with free licence) to give the distortion and coloration not necessarily opinions on the matter. thanks

 

[zoekav]

cowboybob thank you so much for your help, i will browse through and decide which one could be the best one for me.

 

[AnalogKid]

I searched for <phono preamp tube schematic> (without the brackets) and got dozens of schematics.

ak

 

[JimB]

zoekav,
Welcome to the forum.

audioguru Thanks for your input, this topic is subjective and I respect your opinion,

Don't worry about AG, he is a pussy cat really!
But if you want to really wind him up, you need to start a discussion about Single Sideband radio transmitters/receivers.

JimB

 

[audioguru]

The single sideband radio communications that I have heard sound awful.
The head office of a new bank wanted encryption on their new wireless boardroom telephone conference system so I designed and built it with a single sideband suppressed carrier system using Motorola balanced modulator ICs. The voices received on a normal receiver were completely unintelligible but the decoded sounds were exactly the same as the originals. I wondered what "secrets" the bank wanted hidden.

 

[Musicmanager]

I wondered what "secrets" the bank wanted hidden.

Probably something to do with the size of my overdraft !!

are you talking about Acid Rock or RAP? They are noises, not music.

I'd have to differ with this .. .. .. Music is correctly defined as 'Noise arranged in a rhythmic pattern' which is exactly and precisely what Acid Rock and RAP are, but then so are the creations of Beethoven and Mozart and much else between !

It is also true that the only musical instruments that do not produce varying degrees of 'distortion or coloration' via harmonic sympathies are electronic ones that are specifically designed not to do so and as such are actually distorting reality

S

 

[zoekav]

.. .. Music is correctly defined as 'Noise arranged in a rhythmic pattern' which is exactly and precisely what Acid Rock and RAP are, but then so are the creations of Beethoven and Mozart and much else between !

It is also true that the only musical instruments that do not produce varying degrees of 'distortion or coloration' via harmonic sympathies are electronic ones that are specifically designed not to do so and as such are actually distorting reality

Musicmanager Thank you, but i suspect we have opened up a war field here.

 

[AnalogKid]

Hindemith - don't get ME started...

ak

 

[Musicmanager]

i suspect we have opened up a war field here

Nah, we're all firends in here

 

[audioguru]

I attended an audio demonstration where large speakers produced very clear, wideband, uncolored and low distortion sound, sometimes loudly. Excellent deep and well-damped lows (good damping factor because there were no output transformers in the amplifiers) and smooth highs (because the solid state devices had good high frequency response). Then a pretty young lady removed the fake covers on the speakers revealing fairly small speakers producing all that excellent sound. I looked around for the live orchestra or sub-woofer but there was not any there. It made my hair stand up and gave me goose bumps. That was audio reproduction at its best.

 

[atferrari]

It is also true that the only musical instruments that do not produce varying degrees of 'distortion or coloration' via harmonic sympathies are electronic ones that are specifically designed not to do so and as such are actually distorting reality

From Wikipedia I get this: Distortion is the alteration of the original shape (or other characteristic) of something, such as an object, image, sound or waveform.

Hola MM; hope you somewhat agree on the definition above. If so, could you elaborate? Not clear for me.

 

[crutschow]

...................
I'd have to differ with this .. .. .. Music is correctly defined as 'Noise arranged in a rhythmic pattern' which is exactly and precisely what Acid Rock and RAP are, but then so are the creations of Beethoven and Mozart and much else between !
...................

I have to seriously disagree with that.
Noise, no matter what rhythmic pattern is applied to it, is still noise, not music.
To borrow a phrase, music and noise are like pornography, I may not be able to precisely define it, but I know it when I encounter it.

 

[Musicmanager]

Hola AT

You need to be careful with the definition here .. .. .. In the context of my sentence quoted you could just as easily use the word change .. .. ..

.. .. ... .. and as such are changing the reality.

What I was alluding to is the fact that naturally produced sound, that is, sound that occurs as a result of vibration produces sympathetic harmonics from the environment of the instrument, and often from the instrument itself. These days the concept of digital recording and the presence of a sound mixing desk with an over zealous sound engineer have removed much of harmonic colour and as such have changed the reality. This is a huge debate that has been rumbling on for years and will continue for many more and as such too much debate would be out of place in this forum.

However, in music there is a recognised term of 'distortion' which was born in the days of vacuum tube amplifiers when saturation produced unwanted sound effects. These days 'distortion' is deemed desirable and is produced electronically particularly for guitar players, but there are others. If you google 'audio effects' in particular - flange; chorus; and delay - you'll get an idea of what I mean.

Good to hear from you

S

 

[Musicmanager]

Hi Cruts

Noise, no matter what rhythmic pattern is applied to it, is still noise, not music.

So how do you define ' Noise ' then ?

S

 

[Ian Rogers]

Its obviously a point of debate...

I like MY music.. I really don't care if anyone else doesn't....

I know folk that "miss" the old ceramic 78's and the hiss and crackle that came with it... Personally! I don't..

I prefer a CD or a FLAC recording where you can hear just about everything... Every guitar strum every piano key!! ... The thought of a whining inductor from a poor performing PSU coming through the speaker that ISN'T part of the performance, this isn't what I want to hear.

When a rock star scratches the strings of an electric guitar.. That's part of the recording... When the audio signal is deformed by the amp... Well that isn't...

Personal preference....

 

[Musicmanager]

Good Morning Ian

I couldn't agree more .. .. however, there is a world of difference between the effects of a whining inductor and the natural acoustic properties of the environment and the instrument itself.

For example, I trained many years ago as a classical organist and the desire to perform my favourite piece of Bach, Widor or Durefle in an acoustically rich environment such as one of the big cathedrals is huge because of the quality of the acoustic enrichment such a venue offers to the overall performance. But I have provided organ accompaniment for a choir performing for a recording in such a venue, when the sound engineer was intent on 'weeding out' the acoustic resonance of the building we were in because he believed it was not 'pure or clean' sound and as such not part of the performance.

A misguided sound engineer ? Maybe .. .. but for everyone you find who would agree you'll find another who does not .. .. and the jury's still out !

S

 

[audioguru]

It isn't distortion but it is not reality when a lone singer also sings the entire background chorus as the song is recorded over and over for each "member" of the chorus.
I notice that many pop singers today have very faint voices and "kiss" the microphone when they sing. Then every subtle breath is heard loudly and I have come around to like hearing it. The breath sounds are even in the electronic echoes.
Did you notice that many singers today can't sing worth a damn in a live concert because in the recording studio their pitch errors are fixed electronically. The live singers sound good when they lip sync to the recording that is playing.