I meant that I could not offer a comparison between the supply most are using and my concoction.
There is no question you have not imposed any boundaries on trying other supplies or anything else, for that matter.
Just wanted folks to know (again) that as good as this circuit is as given it is worth the trouble to gild it. The time and money will not be wasted.
I cannot think of an instance where you have discouraged going beyond and your counsel is always given with a complete lack of ego.
No matter what we do, it is the SALAS phono amp at heart and that is one very strong heart.
There is no question you have not imposed any boundaries on trying other supplies or anything else, for that matter.
Just wanted folks to know (again) that as good as this circuit is as given it is worth the trouble to gild it. The time and money will not be wasted.
I cannot think of an instance where you have discouraged going beyond and your counsel is always given with a complete lack of ego.
No matter what we do, it is the SALAS phono amp at heart and that is one very strong heart.
By all means. I wanted to leave some non spec altering creativity area open ended to the final builder (the raw psu, the phono coupling capacitors & resistors types choices) because its a hobby and it must be fun and fulfillment beyond a prescribed X good result. But most found the basic supply good enough and that even led to making a board for it later on so to look complimentary and nice.
Salas is right and it is aditional DC filter. It is K Multiplier filter design by Keantoken. It is about 2v Vdrop and it is exactly what I needed for my Raw DC block. I have 49.2V DC IN to my FSP.
Design is here: The K Multiplier
Discussion is here: http://www.diyaudio.com/forums/power-supplies/177516-keantokens-cfp-cap-multiplier.html
After all that discussion about C8 caps type, may be it is easier to drop BG Standard with 470uF 50V. Is that would be improvement over Nichicon KZ? Nobody knows...I see Soniccraft still sale these. Not sure if $31.16 x 2 will be justification for potential improvement (if any) for that swap. Opinions?
I'd say new vinyl or a spliff would improve your listening pleasure more than the Black Gates.
Must be dry....
In serious note, Soniccraft claims that BG can be good for 30-40 years if stored in control environment, which they actually maintain. To be honest, I got red color 680uF 35v NX form them last year for my headphone amp and no regrets yet. It is working like champ. Let's assume that BG Std is in good shape...does it make sense to upgrade Nichi KZ with it?
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.In serious note, Soniccraft claims that BG can be good for 30-40 years if stored in control environment, which they actually maintain. To be honest, I got red color 680uF 35v NX form them last year for my headphone amp and no regrets yet. It is working like champ. Let's assume that BG Std is in good shape...does it make sense to upgrade Nichi KZ with it?
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Went though both boards to make sure all was correct
all as it should be only one board had the wrong R8 ??
will try the gain lift in the week and will let you know
thanks again
regards
Gary
Went though both boards to make sure all was correct
all as it should be only one board had the wrong R8 ??
will try the gain lift in the week and will let you know
thanks again
regards
Gary
Use good quality low ppm resistors for that if you can. It should give a small but noticeable extra gain. Good to let us know.
Hi Nick, my second FSP with ClarityCaps is sounds amazing. I like it more then my firs unit with Mundorfs. It is more clearer sound and I started to head more little nuances that were hided on my first unit.
However, even after significant time which I spent for parts matching, I have balance issue. One channel is louder and my image moved towards it. I tested system with mono CD and all other components are in perfect balance. It might be cart and I'll test it next weekend.
I just want to be prepared for my FSP test if needed. How to test it correctly for gain all over audio frequency range? I know that R8 plays a balance role, but what might be blind step of resistance change -> 1r/5R/10r? I have TX2575 47R at R8 position now. Thank you.
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However, even after significant time which I spent for parts matching, I have balance issue. One channel is louder and my image moved towards it. I tested system with mono CD and all other components are in perfect balance. It might be cart and I'll test it next weekend.
I just want to be prepared for my FSP test if needed. How to test it correctly for gain all over audio frequency range? I know that R8 plays a balance role, but what might be blind step of resistance change -> 1r/5R/10r? I have TX2575 47R at R8 position now. Thank you.
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Do what Andrew said first to confirm there is a problem. Swap inputs also to see if it comes from the cart. Is anti-skating OK for instance? If there is an electronics problem indeed its because of a possibly wrong resistor value somewhere or because of unusually mismatched transconductance for some key JFET position between channels. Anyway, to measure trustfully if without a steady function gen & scope or a calibrated FFT set up, you can do this:
You have shown once a DER EE LCR meter that you own. We will use it creatively in a different role now. It outputs a very steady 1kHz 650mV RMS sine wave from the moment you turn it on. Make a dimensionally tight 6.8k series & 10 Ohms parallel to GND L pad. That will divide strongly both the signal and noise to phono level input territory.
Feed the LCR's output trough the attenuator to the phono channels one at a time using coax and measure the outputs with a DMM in AC mode. They will receive ~1mV steadily from a 10 Ohm output impedance and will do their gain thing. Now you can compare their absolute outputs in mV AC before and after changes you may try. From 47R to 51R (R8) there will be enough loss for instance. But I would prefer you match via R10 due to its not mismatching THD also when compensating. Better use a same scale value trimmer wired as rheostat to sub a resistor and arrive to conclusions. Convert the output levels in dB and try for them to stay under 0.50dB apart. I never seen higher than 0.20 dB channels imbalance in my various builds by just matching IDSS though.
Good news, I checked the bad channel in accordance with Salas's recommendation and found that I had screwed up and installed D2X in the wrong polarity, everything else checked out, swapped D2X around to proper polarity and everything working, luckily I pulled power before I fried R1X. So now I have 3.5v both channels on Tp1-TP2 with 33.2 vdc on right channel and 32.8 vdc on left channel after 1/2 hr warm up and no more adjustment left on VR2X. Still a bit shy of the TP1-TP2 value in the build guide. Salas had advised that I increase R3X a bit to get more adjustment range on the rails. Currently R3X is 9.1K what does "increasing a bit" mean, going from 9.1K to 9.5 K, or a larger move like moving to 15K ?
Thanks,
Paul
Thanks,
Paul
Hello Andrew and Nick,
All is clear in perspective of full troubleshooting way and following methods with signal generator. I just want to be sure that I got attenuators construction correctly.
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The attenuator is alright but the sine wave source and the coax to the phono input must swap places in your schematic in respect to the attenuator