PSU for ACA

Hi folks


I need to build a PSU for the pair of ACA boards I have, which I intend to use to make a pair of monoblocs.


So I was looking at the diyAudio PSU board v3, but building it as a point to point version.

This is the original schematic minus the rectifier section as I plan to just use a monolithic rectifier as I already have several of those.

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For powering an ACA board, I believe I can simplify that to this:


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To build it point to point in the way I was envisaging, can I do it like this?

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C1-C8 would be Dubilier 6700uF 35v caps I already have, but I'm not clear on what values for the other parts, assuming I want a 24V output.
 

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R7 is about 2.2K. It depends on LED and brightness you want but the calculation is the following (Ohm's law): R = 24 - Vled / 10mA (10mA is the standard current in a LED, but you can have a range of 1-15mA, 1mA it is for very efficiency led, see datasheet of the LED). So 24 - 2.2 / 10mA = 2.2k -> assuming that a LED has a Vf of ~2.2V. See datasheet to be sure (range is about 1.4V-2.5V, depends on LED used).
 
Ian, go over to the Pass forum and check the F5 PSU schematic... it uses 24VDC rails.

Some good info there on building exactly what your after. I'm about to build an F5 and still contemplating an external PSU for it, so I can run my ACA from it too!
 
Ian:

You're on the right path. In an unregulated circuit like the one you're contemplating, the rail (i.e., DC) voltage is largely dictated by the voltage on your transformer's secondaries. Use a transformer with 18V secondaries to get about 24VDC after your rectifiers. I built an integrated amp (BOZ preamp and bridged ACA) for my daughter a few years ago which included two power supply boards for the amp -- one board for each channel. Here are a few photos.

Regards,
Scott
 

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Ian, did you ever read Rod Elliotts article concerning a "CapMultiplier - PSU" as the ACA's PSU?
Capacitance Multiplier Power Supply Filter

I did! And I have built one, connected it to my ACA and have been absolutely astonished about
how much superior the sound has been compared to a wall-market PSU, to a SMPS, the forum's
proposal, ...

It is your decision, it is your ears - Rudi

P.S.: Find attached a PCB look-through of the CAPMx PSU that I am using to power my ACA!
 

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stepdown regulator 24v to 18v scematic psu single rail psu for L 18v & R 18v set bias 8v or 24v lenier psu set bias 12v to suplay both chanel L&R chanel ?

#KEFF coda 70 bookself 2 way speaker
 

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