I've had a HD147 head for 15+ years and in that time it's given faultless service.
Obviously with a lot of time on my hands at the moment I've been using it nearly everyday for the last month with no problems and it's powered up around 2-4 hours at a time.
This morning I turn it on and there's a crackling and sort of quiet popping coming from inside the head. I immediately turned everything off, unplugged and removed the two wooden ends of the amp so I could see inside.
It transpires that I can only get it to make this noise maybe once in every four power cycles.
There's nothing obvious, no blackened components or melted wire and the amp stays powered up the whole time and the main power light stays constant. I think the noise maybe coming from the main power switch. It's situated very close to one end so I can get my head next to it and listen as I power up. The switch itself looks in perfect condition but there does seem to be quite a lot of side-to-side play in the toggle switch on the front of the amp...not sure if that's usual for this type of switch.
I know these things are near impossible to diagnose remotely but could a faulty power switch cause the noise I'm hearing ?
It's so easy to get to I'm of a mind to replace it anyway, which leads me onto my next question...I assume I need a SPST toggle switch ? Do I need to be mindful of voltage/ampere rating when replacing ?
Many thanks for your time.