Help! Weird Noises and No Guitar Output from Sunn Solarus

[bradberry00]

My Sunn Solarus is suddenly making strange static, fizz and clicking noises with no guitar output. Noises do not change with volume or tone controls. Tube problem?? Filter Caps are fairly new. The amp was working fine, I turned it off for a few minutes and now it sounds like the below video.

https://youtu.be/HvrTC8b55p4

please let me know where I should start looking. This is my baby and I don't want to be without it for long.

thanks,
-david

[52 Bill]

There are a hundred different reasons that could cause your problem, but I would start by checking or swapping tubes.

[bradberry00]

There are a hundred different reasons that could cause your problem, but I would start by checking or swapping tubes.

I am assuming that because there is no guitar signal output, the main culprit as far as tubes goes would be the 6550s? And also because the sound doesn't change with the volume or tone controls.

[loudthud]

Does any signal from a guitar input get through at all? Try pulling the 6AN8 phase inverter tube. It is between the 6550s but towards the front of the amp.

[52 Bill]

I am assuming that because there is no guitar signal output, the main culprit as far as tubes goes would be the 6550s? And also because the sound doesn't change with the volume or tone controls.

Agree with Thud here, the problem is probably earlier in the amp, not the output tubes.

Remember that each output tube only works during half the signal. So as far as tube failures go both halves (two tubes) would have to stop which is unlikely. There can be a power supply problem that will kill off both tubes, but for both tubes to stop working at the same time would be odd.

If you have a working push pull circuit amp and you pulled out one output tube, the amp will still pass signal. It may not be pretty, but it won't go silent.

[bradberry00]

Agree with Thud here, the problem is probably earlier in the amp, not the output tubes.

Remember that each output tube only works during half the signal. So as far as tube failures go both halves (two tubes) would have to stop which is unlikely. There can be a power supply problem that will kill off both tubes, but for both tubes to stop working at the same time would be odd.

If you have a working push pull circuit amp and you pulled out one output tube, the amp will still pass signal. It may not be pretty, but it won't go silent.

Ok, I will pull the phase inverter when I get a chance this weekend and report back. I might have an extra one in another Sunn I have (but I don't know if it is good).

thanks,
-david