diyAudio Power Supply Circuit Board v3 illustrated build guide

Thanks Jim, I really appreciate your help. I see the current drops off a table after the temperature hits 100C according to the forward current derating curve. I didn't notice anything about the forward voltage drop though. But there's a lot I miss . . .

And thank you, Mark, but it looks like I can use what I have after all.
 
Hi,
this just to report success in building a v3 universal PSU - MUR3020W rectifiers, 8x22000µF capacity, 24V rails. Easy build, works like charm. I was just surprised how hot (still touchable) the heat sinks get...working duty on an 0.95A-biased stereo F6 with ventilated cover plate.

The only "problematic" point I had was that the space between the rectifier heat sinks are quite tight for the transformer snubbers - so some of that went under the PCB. Otherwise, no issues. Thanks everyone who worked on the design of this!
 

Attachments

  • IMG_9394.jpg
    IMG_9394.jpg
    264.2 KB · Views: 439
  • DSC_5158.jpg
    DSC_5158.jpg
    151.9 KB · Views: 448
  • IMG_9040.jpg
    IMG_9040.jpg
    267.1 KB · Views: 427
  • IMG_9026.jpg
    IMG_9026.jpg
    199.3 KB · Views: 459
Hi,
this just to report success in building a v3 universal PSU - MUR3020W rectifiers, 8x22000µF capacity, 24V rails. Easy build, works like charm. I was just surprised how hot (still touchable) the heat sinks get...working duty on an 0.95A-biased stereo F6 with ventilated cover plate.

The only "problematic" point I had was that the space between the rectifier heat sinks are quite tight for the transformer snubbers - so some of that went under the PCB. Otherwise, no issues. Thanks everyone who worked on the design of this!


Might want to insulate those bare legs on the LED, it'd be pretty easy to bend them into a short. Just sayn. :wave:
 
Member
Joined 2012
Paid Member
Forgive me if this has been asked- are there recommendations for connectors so that one can swap out different amp boards at a later time, using the same PSU? I just ordered the PCB and this is my first time building a PSU. Thanks!

Another option is to use Molex bullet plug connectors on the wires.

Snap Plugs and Receptacles - Molex

Colour code them so no mistakes in hookup. The advantage of connection in the wire over connection on the board is that there is not excess force exerted on the board during connection or disconnection.
 
Another option is to use Molex bullet plug connectors on the wires.

Snap Plugs and Receptacles - Molex

Colour code them so no mistakes in hookup. The advantage of connection in the wire over connection on the board is that there is not excess force exerted on the board during connection or disconnection.

Ha! Those connectors conjure up suppressed nightmares of ‘good old’ Lucas electrics on vintage cars. I have a knee jerk aversion to them for this reason but I’m sure they will work in this context. Good point re the stress relief on the board.

If only there was an alternative that didn’t remind of fiddling blind behind an Elan dashboard with those things :)
 
Member
Joined 2010
Paid Member
Confused about wiring wall power to transformer

Screen Shot 2020-06-01 at 10.28.19 AM.png
This picture is from the F4 Build thread. I am confused about the wiring of the AC power to the transformer. I am US 110V power.

I would expect:
AC Line >> CL-60 >> 2 Red Transformer inputs
AC Neutral >> CL-60 >> 2 Black Transformer Inputs
Small Capacitor linking AC Line and AC Neutral

1) This picture appears to show one red wire linked to the mains thru an inrush CL-60 and the other linked directly (in the same hole). Similar for the two black wires. Why aren’t the two reds and two blacks wired identically?

2) Inside the transformer are there two separate red/black >> blue/green paths, or are they linked?

3) On the other end of the transformer am I correct in thinking that one blue and green pair goes to Left Rectifier Bridge, and the other pair goes to Right Rectifier Bridge?

Thanks,

-Tom-
 
Member
Joined 2010
Paid Member
Thanks Mark,

That appears to be exactly what the picture shows. I will wire it that way even though I don't understand it.

Is it a good idea to fire up the power supply before the F6 boards are attached to verify +&- 25 volts and a lack of magic smoke?


Thanks Ben,

Indeed it is an Antek 4218.

-Tom-
 
Last edited:
I just built a PSU for the F4. I've got everything wired up and tested and the amp is putting out fantastic music. I have noticed, however, that the PSU LEDs dim at very different rates. One goes dark immediately (the V- side), the other (V+) stays lit for a little while as the caps drain. Why would that be? Does it have to do with how the F4 boards draw power? On my Aleph J, the LEDs both dim at the same rate which is why I'm wondering...
 
Hi All,

I'm building an Aleph J, got lucky and pre-ordered the last round :). I have the UPS boards as well and an Antek AN-5218 Transformer.
I'm trying to decide on the bridges. Any opinions pro or con for the monolithic bridge vs. discrete? I want to use the boards and build discrete, if only for experience sake, but i'm lost on these values for the snubber resistor, is it essential to build the quasimodo to have a correct value?

I've read and searched a bunch here and on the Quasimodo thread, but haven't found any confirmed values or much talk about this model transformer, seems strange. There's a reference from 2013 for a 170R resistor but that's all i've been able to find so far. If anyone used an AN-5218 in this power supply and knows the value i would greatly appreciate.

Thanks in advance for any knowledge here
 
Member
Joined 2019
Paid Member

I have a basic question for anyone. Re board diodes vs Graetz bridges. If you are looking for the ultimate in sound quality does it make any difference if you use the board with diodes or use Graetz bridges. Its all diodes. And, there are a large variety of each so are there subjectively "best" choices. Same might be said for the caps. It's my understanding this is basically the default Pass Amp PS.
Thanks,
Don

PS, I know what the BOM says.