Tube amplifier bad caps

Hmm...now I'm second guessing. A lot of uncertainty as I've been told it's definitely the filter caps. However, the amp is not even 10 years old and I've been suspicious of this assessment. I've seen what cap leakage looks like and they definitely look fine.

I'll try and explain the problem in more detail. Upon startup, the "bacon frying" sound gradually builds and becomes constant once the tubes are lit. The power tubes flicker with every pop and crack. This symptom used to be only in the right channel and now it's in both. As indicated, I've swapped all of the tubes with new ones. I'm afraid I've probably ruined the new tubes because of this.

I purchased this amp used from a local hifi company that is out of business now. I live in a small city so finding a tech that specializes in tube amps will be difficult. Are there any fellow Canucks out there that know of a tech near Regina? As a last resort, I may end up contacting the UK manufacturer and seeing what can be done.

Thanks guys for your help.

You have probably NOT ruined the tubes because of this, unless one of the conditions below occurs. If your tubes are driven into oscillation over an extended period, then I would worry. Also, if your tube bias circuit goes bad somewhere and the tubes glow red-hot for an extended period, I would worry then, too. I am not sure if this is comprehensive, perhaps someone else may add to this. As far as my experience and my father's advice to me on a problem with my amp goes, this about covers it. He is a retired EE professor by the way.
Are your tubes glowing red-hot, or noticeably brighter than usual? If so, and you let them run this way for a while, get them tested. Otherwise, see how they sound after you have fixed the crackling problem. They should be fine.
Good luck with your amp!

Just a quick observation that bad caps don't necessarily have a visible external leak. I've seen plenty of way out-of-spec ones that appear physically fine.

Do you have a voltage meter? Do you have a schematic that indicates voltages at various test points? (Keep in mind that voltages in a tube amp are often in the 400 to 500 volt range, or even more.) The key is to start a logical testing process to run down the problem.

Cleaning switches is a good idea (and won't hurt anything) but there are a number of possible causes for the noise. A bad solder joint, a resistor damaged from overheating, a mechanical foil trace failure, a smaller signal cap - any of these or others could be the culprit.

Man, this one sure sounds like a bad power switch to me! It **does not** sound like bad filter caps! It *could* be a bad tube, but the flicker really suggests that the contacts on the power switch are arcing and permanently damaged. I would fire the tech that gave you the bad filter cap assessment, and get the power switch replaced.

Atmasphere I like your style ..no BS