Mike Nye wrote:The 'sizzling hiss' in MOST cases is surface-charge noise from DRIED-OUT FILTER CAPS ! ! !
Case in point . . . They're IMMEDIATELY BEHIND the rectifier IN FRONT OF EVERY CIRCUIT in the amp, so you're also gonna hear 'em in the reverb & trem circuits as well . . .
Mike, you obviously know a lot about electronics. Therefore, I assume you also know you cannot definitively troubleshoot something as non-specific as hiss, crackle, etc over a written forum post. Even if it was a fault you could troubleshoot this way, you'd have to rely on the original author to provide accurate (from a technician's point of view) info.
You might be right about the caps, but amps with brand new caps hiss as well. Regardless, in anything other than a newly-built amp, there is a high likelihood of multiple minor issues.