Certainly, I would expect C2 to need a tweak for stability, and/or preserving the ~200k pole.
A value substitution which would be more faithful to Wayne's original gain structure would be (just as a starting point... this is not verified in simulation or on the bench - expect to iterate):
C1 = 4.4 µF or 4.7 µF (if you can find a suitable cap that fits)
R10 = 5 kΩ
R11 = 250 kΩ
C10 ≈ 20 pF
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I did account for the square root in the resistor noise calculation ... sqrt( 4 • k • T • R), where k is Boltzmann's constant, and T is absolute temperature in Kelvin. I used 300°K for simplicity (close enough to room temp).
22 kΩ => 19 nV/rt(Hz)
5 kΩ => 9.1 nV/rt(Hz)
It's actually a bit less than half.
But I readily concede this is all a bit academic - this resistor is inside of a feedback loop, so the noise of R10 is already reduced by something like ~17 dB NFB on the MC setting, even more if you put in J2.
22 kΩ => 19 nV/rt(Hz)
5 kΩ => 9.1 nV/rt(Hz)
It's actually a bit less than half.
But I readily concede this is all a bit academic - this resistor is inside of a feedback loop, so the noise of R10 is already reduced by something like ~17 dB NFB on the MC setting, even more if you put in J2.
If someone can report less hiss-noise when volumen set to max (MJ-method) by changing a resistor to another brand or value I will be happy to know.
I am also happy that I only hear a bit of hiss-noise when volumen set to max (no hum).
I got my first "aha-experience" when playing a brand new record (Sony music). No groove-noise and not a single "pop". A friend I had for the listening test was also surprised. I have written to the company to know more about the pressing and vinyl composition. Only records of such high quality (or close) can justify all the effort that is put into a high end phono stage like the P3 (my own subjective viewpoint).
I am also happy that I only hear a bit of hiss-noise when volumen set to max (no hum).
I got my first "aha-experience" when playing a brand new record (Sony music). No groove-noise and not a single "pop". A friend I had for the listening test was also surprised. I have written to the company to know more about the pressing and vinyl composition. Only records of such high quality (or close) can justify all the effort that is put into a high end phono stage like the P3 (my own subjective viewpoint).
Just to set some expectations - the point of scrutinizing R10 and so on is really just for the enjoyment of thinking through and analyzing what it would take to squeeze a tiny bit better noise performance out of the circuit. And maybe some of us can collectively share our knowledge and learn a bit more about noise along the way. I don't realistically think it's going to translate into a difference that would be noticeable in listening tests. Wayne has already designed an excellent circuit with the P3, better than a majority of other phono stages out there I'd wager, and the reports so far certainly bear that out.
So if you just want a great phono stage to enjoy, then don't hesitate to build it as designed and get down to the real business of listening to music. I'm sure you won't be missing a thing.
For me, this is about nerding out and playing "what if?" with the circuit for the fun of it. A good excuse to dust off some old engineering skills and perhaps make some interesting measurements if I find time. I've had a phono stage on my back burner project list for a long time, but never got round to it. Wayne has graciously spared me the effort of designing something from scratch (I think it would be hard to do better), and the kit availability has made it a no-brainer that I couldn't ignore.
So, huge gratitude to Wayne, 6L6 and the whole crew for getting me over the "one day" hurdle to actually firing up the soldering iron - that's what I love about this place!
Of course, I still feel compelled to change something to "make it my own".
So if you just want a great phono stage to enjoy, then don't hesitate to build it as designed and get down to the real business of listening to music. I'm sure you won't be missing a thing.
For me, this is about nerding out and playing "what if?" with the circuit for the fun of it. A good excuse to dust off some old engineering skills and perhaps make some interesting measurements if I find time. I've had a phono stage on my back burner project list for a long time, but never got round to it. Wayne has graciously spared me the effort of designing something from scratch (I think it would be hard to do better), and the kit availability has made it a no-brainer that I couldn't ignore.
So, huge gratitude to Wayne, 6L6 and the whole crew for getting me over the "one day" hurdle to actually firing up the soldering iron - that's what I love about this place!
Of course, I still feel compelled to change something to "make it my own".
I made it my own by using MJ's UDP3 PSU and using 47k Z-foil as MM input resistors and also doing the "ground lift" in P3 chassis instead of PSU chassis. All probably do small tweaks to make it "unique" so we all think we have the best version of it. I am probably also the only one that soldered in ADA4898 opamps and the only one who know how those sounds
For those of you who snagged kits - if want to get in on a round #2 of PSU parts kit group buy go to this thread and add your name:
https://www.diyaudio.com/community/...no-crcrc-power-supply-parts-kit.406461/page-5
I understand more kits are being prepared, and there will be enough to go around. Be patient.
@6L6 can share more info on that topic.
https://www.diyaudio.com/community/...no-crcrc-power-supply-parts-kit.406461/page-5
I understand more kits are being prepared, and there will be enough to go around. Be patient.
@6L6 can share more info on that topic.