Ampeg SR-212rt Issues

[burbingus]

Hey Guys,

I recently purchased an ampeg superrocket. The guy I bought it from acknowledged some issues and I got it shipped over. I took it to a repair shop and they put in some new tubes and rebiased them.

The problems:
It may just be the nature of the amp, but there is a lot of noise. It seems that there is quite a bit of 60-cycle hum. This may be the cause of the next problem,

when the tremolo is turned on, it creates high volume thumping with each amplitude cycle.

Is this normal, or do I have issues? I'm just not used to tube amps and may just have to adjust.

Thanks!

[Bassman3]

Sr-212rt

Hi this is Dave @ the SLM facility in St Louis. Those amps can thump when the tremolo is turned up to a fast rate. Usually it's the tube driving the tremolo.
The hum problem might be inherent, but let me see what I can find on it.

[burbingus]

Thanks Dave,

The guy who sold it to me had the tubes way overbiased. I'm thinking that he may have burned some caps which may now be leaking. That could cause the noise as well as the excessive thumping which is occuring at all tremolo speeds. I'm not sure, but I'm going to keep looking around to see if I can find the source.