JVM410HJS - FX Loop issue

[George Wilby]

Hi everyone,

I have an issue with my jvm410hjs. I've been playing through my jvm for a number of years now with and without the fx loop on, however recently when turning the fx button on the volume dips dramatically.

This hasn't happened at all for the time I've owned it.

If i leave the amp off for a few days and come back there is no issue until about 20 mins of playing and then it dips again?

This volume dips on any channel and only when the fx loop is enabled.

Anyone have any ideas on what the problem could be? I was thinking maybe one of the valves have perished?

Thanks!

 

[ampmadscientist]

Hi everyone,

I have an issue with my jvm410hjs. I've been playing through my jvm for a number of years now with and without the fx loop on, however recently when turning the fx button on the volume dips dramatically.

This hasn't happened at all for the time I've owned it.

If i leave the amp off for a few days and come back there is no issue until about 20 mins of playing and then it dips again?

This volume dips on any channel and only when the fx loop is enabled.

Anyone have any ideas on what the problem could be? I was thinking maybe one of the valves have perished?

Thanks!

You might be describing a bad effects pedal.

Plug a guitar cable between send and return of the loop (no effects in loop).
Turn on the loop, does the volume drop now / after 20 minutes??

 

[mickeydg5]

It could be relay RL102 acting up.

Tube V104 has the effects loop recovery. Didyou try different known good tubes there?