@UV101 Which caps are you referring to exactly when you say I need to invest in decent output caps? Do you mean the ones that Ray lists on his site as 25v 100uF Black Gate FK? If so, I have those as my op-amp caps right now.
I was planning to further upgrade my PSU caps and do the HDAM bypass next. I've got a nice CMC OFC RCA on its way (man, these posts are heavy on the acronyms). I was definitely planning to hit up Brent up for some SPowers shortly after that and ultimately a C2, most likely. I hope it's OK to do HDAM bypass before regs...
As for the DOS, I think I'd like to have a go at building one at some point. I have a lot of work ahead of me rebuilding my amplifier first. I'll be sure to put the Black Gates for the DOS to one side though.
Hey Ray, how set in stone are those cap values? Are there any that would be OK in larger values?
I was planning to further upgrade my PSU caps and do the HDAM bypass next. I've got a nice CMC OFC RCA on its way (man, these posts are heavy on the acronyms). I was definitely planning to hit up Brent up for some SPowers shortly after that and ultimately a C2, most likely. I hope it's OK to do HDAM bypass before regs...
As for the DOS, I think I'd like to have a go at building one at some point. I have a lot of work ahead of me rebuilding my amplifier first. I'll be sure to put the Black Gates for the DOS to one side though.
Hey Ray, how set in stone are those cap values? Are there any that would be OK in larger values?
No, those values are not carved in stone
It largely depends on the regulators you use. Some don't even like big caps because they can start to oscillate when the ESR get's too low (like some newer 78xx types). If you use a decent discrete (shunt) regulator, they mostly need very little output capacitance. Adding more doesn't improve anything in this case, and only leads to a 'slow' power supply at start-up. Second, the currents in the DOS are constant and not large. It's a class-A circuit, so bigger caps don't add anything there. All in all I think the value can be anywhere between 10 and 470uF I guess.
The output cap has a minimum value of 2.2uF. This will prevent low frequency roll-off. A larger value will make sure the phase-shift at the low end is kept to a minimum. The question is if this can be heard, but who am I to decide that?
Regards,
Ray
These are the DC blockers on the output. I think you said you were using BG FK's that you removed.
With the DOS, you need to use DC blocking. I use Mundorf Supreme. Brent uses Mundorf Silver oil. These type of boutique caps are critical here. Ampohm were exceptional value for money but unfortunately are no more ;-(
Alan, spot on!!!! Where are you going to put them?
Thanks for the replies, guys. I'll almost certainly look at building a DOS at some point, but probably not right now because I've just installed nice new op-amps and 1% silver micas, and as you say, I should probably make regulators and a clock my priority. Anyway, it sounds as though I'll be able to rustle up the Black Gates I need when the time comes without having to take my chances on eBay.
Regarding the blocking caps for DOS, I'm thinking of hitting the pcX sale for some silver/oils to use for input caps when I rebuild my poor amplifier. We talked about this before - I really shouldn't need two pairs, should I? If I'm investing in silver/oils, I'd rather put them where my turntable can also benefit.
Cheers,
Ben
Regarding the blocking caps for DOS, I'm thinking of hitting the pcX sale for some silver/oils to use for input caps when I rebuild my poor amplifier. We talked about this before - I really shouldn't need two pairs, should I? If I'm investing in silver/oils, I'd rather put them where my turntable can also benefit.
Cheers,
Ben
1 on servo 2x dac/analogue /digital 1x decoder then a lot of sepc and za s round the board @ critical locations.
alan
Gonna use a c2 clock can i do dac /servo off 1 clock?
or best use 2,
alan
ps thats the first 500of my 1000 budget gone lol
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No simon this a competely new player im building at the mo,
keeping my main player as a reference.
alan