Session Rockette 30 humming/crackling

[gojirajesus]

Hi, I have a Session Rockette 30, a British solid state amp from a couple decades ago. In the last few months, I have noticed a consistent humming/crackling noise when I play through it. It's not 60 cycle hum, I've checked my guitar through other amps. There's a consistent buzz/hum, and sometimes a crackling sound on louder notes when I play. Since it's a british amp, there's a switch that allows you to change the power voltage. I wonder if the problem results from this? the switch seems kind of loose or broken. If anybody has any ideas about what this could be, I'd appreciate it! It's only like a 200 dollar amp, so I'm trying to decide whether to just buy a new amp or try to get this one repaired.

[nickb]

The crackling suggests a bad connection but could be almost anywhere so no reason to suspect the voltage selector. What happens if you give it a good rap on the top? On these particular amps bad pots is a common problem.

Hum again could any number of things, bad ground connections and / or filter caps feature higher in the list of probable things.

[J M Fahey]

Start tapping every single component and wire (not kidding) or pots/jacks/switches with a chopstick or plastic BIC pen or similar, nothing metallic, one or more will produce the crack or thump or pop.
And yes, even the voltage switch, why not?

Look at the PCB, maybe the component itself is not bad but solder is cracked, or a nearby track.
It just takes some patience, investment will be very low since amp actually works.

resolder suspect pads adding a little fresh solder, donīt overdo it.

Post results, one way or the other.

Price is not the main point here, rather than a Sessionette is a fine sounding British made amp ... will you replace it by a cheap Chinese or Vietnamese amp?

Itīs really worth some effort.

[Jon Snell]

I have had to replace the power module on more than one occasion for this issue.
They used the HY200 module from ILP Electronics. Unfortunately they ceased trading in the early 90s.
I would fit a class D power amplifier for added reliability.