Discrete Opamp Open Design

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Some of us like to also confine currents to loops as local to a given circuit section as possible

This is very important Brad, thank you.
If all amplification stages are connected in series (think board level) to the PSU, local RC decoupling alone, does not.
Parallel connection to the PSU plus local decoupling does.


hmmm... more tiny ants to herd.

Ah, now I see bear. I overlooked your true nature


George
 

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Part of what I was thinking is if there are consequences to designing for high PSRR or not.

Does making the circuit "do work" to cancel PS "stuff" effect the desired operation, or not.

_-_-bear

I think yes. IMO the good audio circuit design should have

- very high speed, both wide bandwidth and very high slew rate
- very high immunity to RFI/HF demodulation and detection
- high High Frequency PSRR
- low distortion with no (or maximally suppressed) higher harmonics
- low noise
 
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This is very important Brad, thank you.
If all amplification stages are connected in series (think board level) to the PSU, local RC decoupling alone, does not.
Parallel connection to the PSU plus local decoupling does.




Ah, now I see bear. I overlooked your true nature


George

Since you cvan't have all your loads directly at the psu (unless you give each stage its own psu) a good way is to determine the stage with lowest PSRR and put the psu closest to that. And, if you're serious, use remote sensing for the regulator at that stage.

jan
 
Low crosstalk up to high frequencies is on my list too. Even a good potentiometer has enough parasitics to screw that up in the treble.

Electronically speaking, everybody shall agree that crosstalk at high frequencies is an undesirable thing as it looks as a parasitic signal.
But for a good stereo rendition, it may not. Who does remember Edeko's articles in Electronics World ?
 
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More details intack with high isolation beteen channels-

In some old timey circuits there was a "blend" control to have you cover that "hole in the middle' with some mono. That helped when speakers were too far apart.
Short version -- If you mix/blend left and right towards mono you will find a lot of info gets cancelled out in the process. That is the effect of reducing channel seperation or isolation -- if you want all the details in tack, you design circuits with as little 'blend' as possible. - RNMarsh
 
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I think that this processors i mentioned inverse the channels and then blend them into the other, some with frequency dependent EQ. The argument is that this cancels the acoustic bleeding of right and left ear getting information from the opposite channels too.
Anyway, as much as i tried this it never satisfied me. One was that i could only hear the effect when my head was clamped like in a vice and the other was the rather poor QUALITY of the sound i got so maybe the processors had mediocre electronics. Also the artificial echo generators i bought at the end of the 70th in full rave got switched off after a while. Even multichannel SACD never satisfied me. I can not really describe the feeling but i got disturbed and that disconnected me from the music. Mono is not for me ether, i am definitely a two channel vinyl guy. Maybe because i was raided that way and it feels familiar.
 
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Here is a comparison of measurements. One is the Kleos that has both coils wound on the same square former in 90° and the Atlas that has a cross with 4 arms. 2 coils for each channel.
The improvement in crosstalk is obvious. Still this would be very poor for an amp. Yes, i know, Vinyl has no right to sound as good as it does.
 

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This cartridges are voiced with a special STAX headphone with extremely low mass.
Mostly critical choir music. There is a cutting and plating loss in the treble and measured more towards the inner side of the grove there is around 3dB loss in the treble too.
I can only tell you that they do not sound spitty at all and yes, extended overtone spectrum differentiates vinyl from CD also i know that vinyl is not very accurate over 10kHz. It may be the simple PRESSENCE of overtones and not the EXACT amount.
 
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