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CRC Power Supply (Class A amplifier)

fab

Member
Joined 2004
Paid Member
Too much unobtanium? or is there a way around that?
I read the first few pages and last 8 pages.

Only the Mosfet drivers are not production active parts. You can still find them and already matched from good reputation members here (ex. liubincalvin, nicmac) or else. Lateral double die Mosfet output from Exicon are easily available and shipped quickly from Profusion official Exicon distributor.
You can find more info here:

USSA-5 PCB GB

In general this is an apparent simple circuit but based on best audio transistors available. The topology is similar in principle to Pass F5 but adapted for lateral Mosfet output instead of vertical Mosfet. Pass is using positive feedback in F5 topology in order to use lateral Mosfet (see F7 thread). However, positive feedback can be quite tricky and only some members have disclosed their own implementation since Pass is not disclosing its design since still an active selling amp on the market...

Fab
 
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Hi, could you PM me about price for 2-4 inc delivery to Finland, thanks!

I would like to purchase two boards.
A couple of years ago I purchased 4 United Chemicon EKMH350VQT563MB80T on a whim.
Despite whatever Mouser's website says, they have 5 leads and I can't find the specs in the data sheet (35V models stop at 22,000uf on the data sheet)- but am holding one in my hand - they do exist.
Spec's listed on the Mouser website are

56,000uf
35V
ESR 8 mOhms
Ripple Current 8.29 A
40mmx80mm

If you have any suggestions for building with these (or reason to NOT build with them:confused:).
Maybe something more robust than a CL-60 for mitigating power on thump.
If that's obscene for the capacitance, maybe dual mono PSU's with two transformers? When building dual mono would one half the transformer size - instead of a single 400VA, 2x 200VA?

Not sure what amp I'm going to build next, probably an M2, or F6,

Sorry guys i dont know if responded earlier,
let me know if you are still interested, i shall send you the quote.
regards
prasi
 
Hi Project16 and Prasi,

I was looking for a psu for my Cordell Super Gainclone project and was unsure which way to go until I stumbled across your designs (schematic and PCB). Seeing so much attention and confidence being given to the design, I thought I'd try a home brew PCB.

I went for the model with caps on the diodes and left out the other options for the sake of simplicity. Its on a 6"x4" 3oz Cu board. I only had 10,000uF caps and 0.1 Ohm 10W resistors so that's what I used. Definitely works!

Thanks for all the effort.
Regards
Mike
 

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Hey Prasi, a while back you mentioned a CRCRC PCB.
https://www.diyaudio.com/forums/gro...wer-supply-class-amplifier-4.html#post4953822

Did this ever materialize and are any available?

Best,
Silas

Hello Silas,
It uses a CT and single bridge.
How about making it into a dual bridge and dual secondary design? been wanting design something for a break. Tarkus speaker building took too much of my energy and time and no where near finished:irked:.

Lets take this CRC to the next level:smash:.

regards
Prasi
 
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Now we're talking! Although i have to acknowledge early on that talk is cheap and I am a babe when it comes to electronics, so the majority of the heavy lifting (ie. designing) will be on you...

I just was playing around with PSUD2 trying to compare modeled ripple values for the standard FirstWatt PSU design using different total capacitances/rail (CRC), and comparing them with a CRCRC setup. I know i cannot necessarily expect psud2 to accurately estimate ripple, but the comparison was interesting (see attachment). DISCLAIMER: This is simulated data only for single rail PSU ripple into 8R load and has no experimental verification/follow up.

I know this comes as no surprise to people who actually know something about electronics, and i've seen the sentiment several times here on DIYaudio that a CRCRC will net you lower ripple for the same C. But since i have a stock of 15 and 33 mF caps i would like to use for a future FW build, and it seems (according to PSUD2) that 33mF caps used in a CRCRC will give performance similar to a CRC using very large (>>35mm snap in) caps, i thought why not look at this route also.

Now, i am sure there are several counterarguments, one important one being "the firstwatt PSU is proven and definitely good enough for purpose", but since this is DIY we are free to pursue our own screwed up overwrought ideas :cool: And who knows, for some this might actually be really useful (i don't see a lot of CRCRC PCBs available out there)!

So here is a wish list that you are free to discount as you see fit since you are the designer (not to mention the more knowledgeable of us on this matter).

- as you mentioned yourself, dual bridge/dual secondary (just like the standard FW)
- Possibility of mounting discrete diode bridges, or a snap-off diode section (i guess the latter makes more sense, as the discrete diode bridges are probably better off mounted to the case)
- Room for 35mm caps (or bigger) at least 33mF (and also a few sizes larger) seem to be available, which gives close to 200 mF/rail.
- Small enough to fit into modushop 4U/300mm chassis :Pirate: I know this is a tough one...

Feel free to add more.
 

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