Class-A amps have all the power running all the time and release it to the speakers. Class-AB have to modulate the power from the PSU.
It's the same for Shunt regs vs. series regs.
(Yes, the descriptions of operation are paraphrase, but you get the idea...)
Sounds like you need to build a Pearl.
Yeah, I've been looking at the pearl and the phonoclone. Right now I am running a Le Pacific (BHL audio) phono stage off batteries. Sounds pretty good. I'll probably decide on a new cartridge an build a compatible phono stage after that...Probably go w/a Denon 301 II or a dynavector 10x5. Right now I have a Denon 110 and a Ortofon OM20 on a Thorens TD-145. But that's a different thread...
Also, any interest/comments on a UNREGULATED power supply for the BA-3 FE? I am thinking like 20,000uf per rail, maybe CLC, 100V transformer. I don't listen loud, I could deal with the noise of the unregulated supply, maybe. What I am looking for is increased dynamics and drive. Bad idea?
Build the Pearl 2. It's completely awesome.
If you were to do an unregulated supply, I would suggest CRCRC at the minimum, but that will still do nothing to address variation in the mains voltage. Is it worth a try? Absolutely!
Start with 10,000uF caps and 10R resistors, or whatever you happen to have on hand in that general ballpark.
If you were to do an unregulated supply, I would suggest CRCRC at the minimum, but that will still do nothing to address variation in the mains voltage. Is it worth a try? Absolutely!
Start with 10,000uF caps and 10R resistors, or whatever you happen to have on hand in that general ballpark.
Thanks
Did you use Fairchild FQP3N30 and FQP3P20 parts?
Would there be subtle sound differences between the Fairchild
vs. Toshiba or this would be significant? Any complaints with
buying from ebay for the Toshiba pairs?
You matched parts for Left and Right Channel, since there is only one
comp. pair?
I did not care for the sound of the B1 either IMHO.
JFET BOZ was nice.
Nice.
What am I missing? BOM says 1000uF 25V and supply rails are 24V
why not use 35V caps to derate? No need because it's regulated?
35V caps too big to fit PCB?
Good 35v caps wont fit. I have 35v nichicon kz and they are mounted above the board because they are too big. But iam running 30v rails.
Iam not sure the 1000uf electrolytics see full rail voltage...they might get less. I think i remember zen mod saying they only see 10ish volts but dont quote me on that...
Iam not sure the 1000uf electrolytics see full rail voltage...they might get less. I think i remember zen mod saying they only see 10ish volts but dont quote me on that...
Do you know what the lead spacing is for the 1000uF 25V,
is it 5mm or 7.5mm?
Just want to confirm before I order parts:
10dB Gain:
R5,R6 200R
R10,R11 65R
R13 170R (330 2W||330 2W)
Do you have Avvid or Mouser PN# for correct size Heatsinks?
Which coupling caps did you go for? How does your sound?
I think I will try obbligato premiums. lowest price of something decent,
anything with 10uF for high end is killer on the pocket
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http://www.diyaudio.com/forums/pass-labs/195303-burning-amp-ba-3-a-75.html#post2997934
If the voltage at the G-S of the output FET reaches >20V the FET will be toast. The Cap obviously dosen't need to be a higher breakdown than that
I used a 16V 680uF.
If the voltage at the G-S of the output FET reaches >20V the FET will be toast. The Cap obviously dosen't need to be a higher breakdown than that
I used a 16V 680uF.
Last edited:
http://www.diyaudio.com/forums/pass-labs/195303-burning-amp-ba-3-a-75.html#post2997934
If the voltage at the G-S of the output FET reaches >20V the FET will be toast. The Cap obviously dosen't need to be a higher breakdown than that
I used a 16V 680uF.
Yes, you are all correct. I first thought it was just power filter cap across the rails till I looked at the schematic again.
Thanks for pointing that out.