There was a discussion about a very similar sch, where it was agreed that the NFB should tap into the Signal Return and NOT into the Power Ground.
That sch is now out of date following that agreement.
And that makes the post9735 sch wrong as well.
Maybe most of the designers are don't know Your calculation, because mamy commercial amplifier let the very low frequencies into the amplifier.
The location is OK for the R54, if You use it in integrated amplifier. It works against the local ground loop between the ground of the input stage, and the output stage. I did many fighting against it. And I got the solution from Marantz PM11s1, which use this resistor too.
I use this amp in dual mono configuration, so I don't need the common resistor to separate the signal ground from the power ground.
Sajti
The problem mentinoed by Andrew is not exist, as this amplifier has no DC blocking capacitor in the feedback route. The LF limit is 0.15Hz in the DC servo.
Sajti
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I don't think Ostripper changed the Kypton-ND Servo grounding. He did change the Kypton-V and Symasui. Those were the versions Thimios was seeing the strange servo behavior in. Here's a quote from Pete.
"I updated the servo schemes in those. Going with a much lower servo FB
impedance solves any slower settling times.
5.6K from TLxxx output to the NFB node gives <50mS settling and just
boosts global gain by a couple DB.
All the servo'ed creations ... (even my present leach/spooky) clone use
that 5.6k (DC) 22-27K (AC) feedback "mix". Nearly instant DC settling.
Edit - I have the V/symasui/spook - all reference the TLxxx (servo) to the signal ground
(lifted -4.7R). You might have the prototype versions - the PCB house versions are
the same (lifted servo reference).
OS"
I'm not sure about the schematic but the screen layout looks the same as the one that Thimios used and his Kapton nd worked fine as far as I know.
Thanks guy's,
one last question. I have measured the 10uf poly cap and the esr is 0.02R. A normal electrolytic of 4.7uf is 2.6R. I suppose the lower the esr the better ?😕
one last question. I have measured the 10uf poly cap and the esr is 0.02R. A normal electrolytic of 4.7uf is 2.6R. I suppose the lower the esr the better ?😕
