Budda Superdrive schematics / filter cap identification

[aweste]

I recently got in a Budda Superdrive 30 for repair with a low 100 Hz hum. No problems with the tubes so next thing to check was the filter caps. I noticed they were changed to used ones with insufficient voltage rating(!)
Also I suspect the capacitance is wrong (don't remember the actual value, writing this from my work).
I can't find the schematic and Budda haven't responded to my mails, can anyone help me, either with a schematic or information about the correct values?

[Jon Snell]

From what I can gather there are a pair of 100u 350v caps in series as the first tank capacitor and the other three are 22u 500volt. There is about 500v available on the first pair.
100HZ hum is main smoothing so if you start by replacing those first and then evaluate the result.
Not sure about which version you have, there are two. The Combo Series 2 have an extra 22u cap. Hope this helps.

[aweste]

Great, thanks a lot!!!

It's a combo with the purple PCB. The caps are 100 uF/450 Volts, didn't realize they were in series. So at least the values are OK.

Funny thing is when I got it in I was about to register it in my repair database when I noticed I had repaired it for a local music store like five years ago or so. My repair note from that time says I changed these two caps.
Then half a year ago the customer turned it in to another local music store and they handed it over to some local consumer electronics repair guy who doesn't have a clue about how an guitar amp should sound (I used to do repairs for this music store but when I got to busy a couple of years ago they found this clown...). I can tell they've changed the caps once more since there are traces of glue on them and I certainly never put in used parts in an amp.
The customer got it back but was of course not satisfied so the music store called me and here I am...

Looks like it's a pain in the ass to get the PCB out, I have some vague memory of it being quite difficult.

I've tried to hook up another cap in parallell with the existing caps (one at the time) but the hum didn't go away which confuses me. Maybe I should have a look at the three others.

[aweste]

Your schematic doesn't correspond to my amp. The caps are not in series, one cap is connected directly to the rectifier output, the other one is connected after the first B+ power resistor (1 kOhm). The B+ is around 500 Volts which makes the 450 Volt rating insufficient.
Also there's a choke in your drawing, there isn't any in this amp.

[vintagekiki]

I can't find the schematic and Budda ...

https://el34world.com/Forum/index.php?topic=13303.0
Budda Superdrive 45

[aweste]

https://el34world.com/Forum/index.php?topic=13303.0
Budda Superdrive 45

That thread is about Superdrive 45 and 80.

[vintagekiki]

Superdrive 45 is written below the link.
The link is listed as first aid only, until the original schematics are found.

[fewa]

There is some budda schematic in Peavey Revalver 4 software.