Test busted Amp

[Sharkfin]

I think my Randall RG75 amp is busted, it doesn't sounds as sweet and as loud as it used to. The owners manual doesn't have much info and there's no resistors to replace, that I know of. Does anyone know of any test you could perform on it?

[DonP]

I think my Randall RG75 amp is busted, it doesn't sounds as sweet and as loud as it used to. The owners manual doesn't have much info and there's no resistors to replace, that I know of. Does anyone know of any test you could perform on it?

Why would there be resistors to replace?

Busting your chops newbie. I think you meant there isn't a fuse to replace?

You've already done the test - play through it - and it doesn't sound right.

If you don't know much about amps I'd say got find a tech.

You can try swapping out preamp tubes, but if it isn't as loud, it sounds like you may need power tubes. Power tubes need to be biased to run properly. And, if it's not the power tubes, you would have spent money for no reason (hence, get a Tech).

Did you do anything to blow the amp? Playing it without a speaker? No letting it warm up before turning on the standby?

Maybe open it up and look for burned components? Watch out for high voltages, however.

[Spivonious]

Depending on the difference in loudness, it sounds like you need new power tubes. It will need rebiasing anyway, so take it to a tech.

[Sharkfin]

Thanks, I did mean fuse. No mention of fuses or anything else on the half page owners manual. I'm clueless to all of this, I do know it's a solid state amp as opposed to a tube amp. Do solid state amp's have power tubes, preamp tubes?

[StukaJU87]

Do solid state amp's have power tubes, preamp tubes?

No, although I had an old Marshall Valvestate that had what looked like one 12ax7 in it.

[DonP]

Thanks, I did mean fuse. No mention of fuses or anything else on the half page owners manual. I'm clueless to all of this, I do know it's a solid state amp as opposed to a tube amp. Do solid state amp's have power tubes, preamp tubes?

If it's not a tube amp, forget everything I said except for finding a tech. The only fix for a blown solid state amp involves tracing down the problem component(s) and replacing them.

Also, instead of killing the amp by playing without speakers, a SS amp is killed by shorting out the load, or using to little resistance. Like if you amp requires 16 ohm speakers and you give it 4 ohms.