NFB-free discrete IU

[anli]

...for +/- 2 mA input: schematics and "harmonics' SPL". I have designed it to be used (and it is in use) with PCM63.

[jcx]

sorry but EF are 100% negative feedback circuits - check EE textbooks instead of Audiophile rags ad copy

[anli]

Originally Posted by jcx

sorry but EF are 100% negative feedback circuits - check EE textbooks instead of Audiophile rags ad copy

Thanks for your so deep schematics analysis!

Please, stop terminology war here, OK? And, please, stop speculations about forum members' reading - you don't know me, my education, my reading and so on. Just stop. And be kind. Aha?

[jcx]

"no negative feedback" is a Audiophile marketing construct - doesn't help diy memebers learn how to design, evaluate circuits

few useful electronic circuits can be designed without negative feedback - in your circuit's case there are multiple local negative feedback subcircuits

don't title threads with such loaded terms and you won't have "terminology war" "problems" I wouldn't bother if you accurately used "no Global negative feedback" in the title

[anli]

Unsubscribing..

[Trevor White]

Originally Posted by anli

...for +/- 2 mA input: schematics and "harmonics' SPL". I have designed it to be used (and it is in use) with PCM63.

what is the input impedance of this circuit ?

For an IV converter it needs to be very low but I don't think it is much better than one grounded base circuit.

[tinitus]

whats up guys ?

why do you behave like this, just because of a 'simple' schematic ?

if you have no interest, just walk away

personal posts removed


moderation

[anli]

Originally Posted by Trevor White

what is the input impedance of this circuit ?

Few Ohms - depending on used Q4.

Originally Posted by Trevor White

For an IV converter it needs to be very low

Any schematics is a result of compromises in designer's model of the world (and, in audio, it depends on experience of multi-years music listening and correlation between used schematics topology and subjective opinion) To my taste input impedance is sufficient for the case (DAC output impedance about 670 Ohms - it is simulated with Rdac).

Originally Posted by Trevor White

I don't think it is much better than one grounded base circuit.

It is common base - Q2 just fixes input voltage about zero in thermo-independent way.

[Torchwood421]

Hi anli, How does it sound? I'd be interested in using it with a TDA1541A. Have you tried an AD844 based I/V? Thanks for any comments... Dave

[anli]

Before current one I have used an IU as attached (the schematics isn't my, as a result - fragment only). To my taste, current IU is distinctly better (the difference isn't subtle): "Cu is Cu rather Al" - you see? While technologically it is easy to replace an IU (it is separated from main DAC board), during almost two yeas I haven't any intentions to design something better (but, say new amplifier has appeared ). Mostly I listen to live records (mainstream 50-60 jazz and different classical music).

You see, it is just subjective opinion.