finding/replacing filter capacitors....

[gonzoamerican]

hey! im new to opening my gear and pedals, and think i am in need of replacing a filter/power capacitor? judging by the other posts that i could gather information from, this is my probem. i just don't know where i would start looking, for there alot of caps in my amp [sunn beta lead]. all the caps are 3kuf 50V, i just don't know which one to switch out...

the symptom is that the amp works, just doesn't feed full power in the output. the power is there, just not getting through to the speakers [or even the speaker outs on the amp]... kinda like a power warble of some sort.

if anyone can gimme some advice thatd be great.

reason being i want to do this myself is my acoustic 220 just had the same thing happen to it, and is still in the shop, and i no longer want to have to bring my gear to someone for such a simple fix. and if anyone would know why this happens to my amps, that would also be helpful... like maybe having something to do with ohmage or is it just the fact i drive my old amps like a frikken monstertruck?

any help?

[gbono]

The two caps you mentioned - 3000uF/50V - located on the power amp PCB are the power supply filter caps. They might be difficult to find since they are axial leaded aluminium electrolytics - checking Digikey & Mouser they didn't have stock. You might try some radial packages.

[trem]

The two caps you mentioned - 3000uF/50V - located on the power amp PCB are the power supply filter caps. They might be difficult to find since they are axial leaded aluminium electrolytics - checking Digikey & Mouser they didn't have stock. You might try some radial packages.

I do not know anythig about Sunn Amps, but are you sure they are axial and not radial? Seems like a lot of stuff on a PCB are radial. Whatever, you guys know what you're doing. You might try the link below and see if they can help you.
Just wondering, how do you know it is caps and not some of the power/output transistors? I do not have much experience with SS amps, so I am just curious.
Good Luck

3000uF Capacitors

[Enzo]

The secret is not to look for old non-standard values. No one has 3000uf 50v caps, but Mouser does have 3300uf 50v axial caps. That is a standard value.

647-TVX1H332MDD In stock, $5.18 each

If you wanted screw terminal caps, they also have them in stock at $15-20 each.

But I would not be so confident in the diagnosis.

The Acoustic amp is a single supply power amp with an output cap to the speakers, while the Sunn is a conventional split supply with no output cap. These two amps are quite different. SUggesting that whatever was wrong with one was the problem with the other is a pretty shaky proposition in my mind. it might be totally correct, but I have my doubts.

And saying you heard somewhere it might be a cap problem, which one should I change is an impossible question to answer.

Plug your guitar into the powr amp in jack. (The master accessory return jack) Does that sound OK?

[Enzo]

The Sunn Beta main filters are axials, right on the powr amp board.