Power supply layout for Expresso

erigm · Post by **erigm** » Wed Feb 23, 2005 5:57 pm

I was looking in the "files" section and couldn't find any layouts for the power supply board. The chassis layout file shows all the mounting points for everthing but the power supply board. Is there any information on this? Also, how would changing the orientation of the transformers affect the amp (both of them 90degrees ... so they are still 90degrees different to reject noise)? Most amps have the power tranny orientated the opposite way I think (the bells front to back). Thanks! This site is awesome!

snide · Post by **snide** » Wed Feb 23, 2005 10:36 pm

Hi,

I don't know if you can open visio files so I put a possible layout in a word document (zipped). I made this layout for my build and it worked great. This also has a corrected bias circuit for the A1a version. Let me know if you want the visio version. This is totally my take on the circuit, so feel free to change to suit your needs!

Eric

Mark · Post by **Mark** » Thu Feb 24, 2005 8:45 am

You both are quite correct about the power supply layout.

I have looked at the power supply layout of the amp "Ginger" which I didn't like at all. I also have looked at various clone amps, and the thing which is instantly noticeable is that everyone copies the board layout, but no one copies the power supply layout.

The Komet has a nice layout, and something like that would be good.

I dare say in the future I shall come up with a power supply layout that I'm happy with, but until then............

erigm · Post by **erigm** » Thu Feb 24, 2005 5:18 pm

Thank you snide for that nice layout ... looks good, and I downloaded and opened it no problem. One thing though, isn't there supposed to be an 80uF cap there somewhere for the plates? Or did you put it somewhere else? Thanks!

erigm · Post by **erigm** » Thu Feb 24, 2005 5:19 pm

Thank you Mark! Let us know what kind of layout you settle on.

erigm · Post by **erigm** » Thu Feb 24, 2005 5:22 pm

Oh, I see Snide. You used two 160uF caps in series (with the 220k in parallel with each cap). One quick look and I thought they were part of the bias supply ... but then I saw the bias supply. Anyway, thanks again! What is the manufacturer of the 160uF caps you use ... and what is there voltage rating? Thanks!

snide · Post by **snide** » Fri Feb 25, 2005 1:23 am

Hi erigm,

The caps are made by UCC and have a tolerance of -10/+20%. They have a conservative voltage rating of 330vdc. They are available from Mouser under P/N 661-PH330 The cost is $2.23 per cap.

Eric

Mark · Post by **Mark** » Sat Feb 26, 2005 3:07 am

I shall come up with a power supply layout that I'm happy with this year. I do know that Matt Taylor has a layout for the power supply that he has been working on.

One of the reasons that I haven't come up with a layout yet is that the caps of preference in a Trainwreck are Mallorys. I'm also against using two 160uF caps in series if I can as they use up too much real estate. I should point out that I have no idea at all if the Mallory caps work any better than any other brand of caps in the amp. I purely working my way through it all and try to come up with a layout that can accommodate many brands of capacitor.

I shall be coming up with a layout sometime this year, at my usual past no doubt!

The Amp Garage

Power supply layout for Expresso

Power supply layout for Expresso

PS

The unfinished work.

80uF cap?

Re: Power supply layout for Expresso

Snide, I found the "80"uF cap!

caps

Trainwrecks and Mallory caps.