Jet City JCA50H buzzing - Sorted!

ecc83

Yeah that’s what the guy I’ve spoken to has said, for £35 plus parts it should either be diagnosed/fixed or I’ll know it’s a gonner!

That's more like it! But, don't take the guy's word for it if he says 'uneconomical to repair' and let him keep the amp  for 'his trouble' . ICBM says they are very good amps and so the power and PT traffs would be worth more than that at least.  Neither of those components have failed.

Dave.

p90fool

Exactly, there isn't a component in it which is expensive enough to write it off. 
They're great amps, and very simple. 

Fez

I agree with @p90fool ; I would very surprised if it couldn't be fixed by any half decent tech

brownovich

Hey everyone,

Just wanted to give you all an update, it LIVES!

The tech I found replaced a couple of pre amp valves that were on the way out (although not yet fully gone) and did a little rewiring. Sorted!

I might do a little video to show it’s ok as I’m still hoping to move this on (I would understand people’s waryness of going anywhere near it after this thread lol)

Thanks so much to everyone for your help and advice!

Chalky

That's great - but what does "a little rewiring" mean?!

ICBM

It puzzles me too. Firstly, there is very little wiring in a Jet City - it's almost all PCB - and secondly it's very unlikely for two preamp valves to have the same fault. So I'm curious as to what was actually done.

Can you get a pic of the insides?

brownovich

To be exact I honestly couldn’t tell you as I’m pretty much useless with electronics (as this post probably suggests!) He mentioned something about the heater wires being a potential cause due to their location on the pcb.