JCM600 212 Combo, No Overdrive Sound

[Dega500]

When I switch (panel or footswitch) to the overdrive channel I get no sound. Clean works great with Green Light. Overdrive has no sound and the red light does come on.

Live with coverband I run my Digitech RP500 mep into the parallel effects loop and everything there works fine. I like to jam straight JCM600 sometimes and miss my overdrive channel.

Any tips or pointers on what I might look for inside? Could it simply be a pin or pins on one of the preamp tubes assigned to the OD channel? Relay? Power Supply?

Thanks,

Dega

 

[duffhuff]

Hi.

Is there absolutely no sound at all, regardless of whether the gain and volume pots are turned up or down?
How old are the pre-amp tubes? V1 is split between the clean and o/d channel, V2 is only used for o/d, so you might want to look at swapping those out.

 

[Strateuphoria]

Those models were prone to cold solder joints and component failure.
Have it looked over by a good tech.

 

[Dega500]

Hi.

Is there absolutely no sound at all, regardless of whether the gain and volume pots are turned up or down?
How old are the pre-amp tubes? V1 is split between the clean and o/d channel, V2 is only used for o/d, so you might want to look at swapping those out.

There is no sound at all regardless of pot adjustment. The pre-amp tubes (JJ's) are a couple of years old and probablt have less than 40 hours on them. Actually, by going straight into the parallel effects loop with my multi-effects pedal when we play live they have alot less than that.

I'll swap those around and see if that helps.

Thanks,

Dega

 

[Dega500]

I never updated this, sorry:

It was a bad preamp tube in V2.

Thanks for the advice.

Dega