Pearl Two

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Can't say about Pearl's particular susceptibility to PSU types, having no direct experience in Pearl, but experimenting is the holly grail of DIY, so good luck. Always use oscilloscope to know that different supplies cooperate OK for clean rail results before comparing.
 
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Voltages across R21, R22, R23, R24 are:

L 69.4mV; 69,3mV; 69.8mV; 70.1mV
R 69.1mV; 69.6mV; 69.2mV; 69.8mV

Other voltages around the circuit are pretty close to Wayne's reference, the drain of Q4 with 20.5 instead of 21 being most "innacurate".

What is the safe margin for 0 DC point setting? While my DMM is set on averaging I manage to set it from 0 to 0.01V. How long I should watch the behaviour?
 
Added 1K to R9 in parallel. Q3 reads:

C 10.8; 10.9V
B 9.4; 9.3V
E 8.75; 8.65V

Looks like more in the ballpark?

Yes, ballpark :D

Voltages across R21, R22, R23, R24 are:

L 69.4mV; 69,3mV; 69.8mV; 70.1mV
R 69.1mV; 69.6mV; 69.2mV; 69.8mV

Other voltages around the circuit are pretty close to Wayne's reference, the drain of Q4 with 20.5 instead of 21 being most "innacurate".

What is the safe margin for 0 DC point setting? While my DMM is set on averaging I manage to set it from 0 to 0.01V. How long I should watch the behaviour?

It always wander a little. Wanders less when in enclosed box. Don't worry, as you have capacitors series with output. It won't cut too high in the output swing either. 50 mV +/- are not a crime :rolleyes:

Nex thing, wire in / out and listen ? :cool:

Best,

nAr
 
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finally

It's up and spinning :hypno2:

Pheew, it took time this build! So, firstly, thanks all for the help provided. I wouldn't be listening to it at the moment without you, guys. Special thanks to Anaël and Salas.

I've spinned about 5 LPs until now. First impression, it sounds better by a notch to my previous RIAA. If it was mechanics, I would say somebody has tightened the screws in the system. And of course it's tomb silent. So in general let's say the state is more solid right now :)

Other benefits may appear after more listening. It could be, that my rig is not helping to hear the full potential at the moment too. But I have to say, at least to myself, that my comercial, "dwarf" in comparison GSP unit wasn't bad at all. It might have some tiny benefits even. But as I said, I should better listen more and compare.

My cartridge loading resistors are 47.5K and my cartridge loading spec. resistance is 47K. Hope there's no mismatch? I've also lowered gain. R16 is set to 47K. I had way too much of it when with 100K. I wonder if I can measure my gain somehow now? Maybe it can even be lower? Chance of oscillation?

I don't have C9 installed. Wonder if it was there for any reason at the beginning.

HFN test record says the system is in phase. I swapped +/- leads on both channels on the cartridge.

Crikey, it's hot down here. About 30 deg. C. inside. So both DCB1 heatsinks and Pearl negative one is sweating around 50C. Closer to the winter, I would love to hear if upping CCS helps.
 

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Hey, Nice setup dude :)
I can see "my" Allen minimalistic replicas running at the outputs ;)

Good to hear no noise at all. Gain setting is also absolutely relevant.
47k5 as cartridge load is perfect, no need to think for a load mismatch compared to 47k value ;)

Best,

nAr
 
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Added 1K to R9 in parallel. Q3 reads:

C 10.8; 10.9V
B 9.4; 9.3V
E 8.75; 8.65V

Looks like more in the ballpark?

Changing R9 is a bad idea. It is part of the RIAA equalization network, as Wayne gently pointed out to me earlier in this thread. You should leave its value alone.

To adjust your bias you may instead lower R10. See my post #1180.

THEN report on the sound :)

By the way, congrats for a beautiful build.
Pierre
 
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