Volume fluctuates in Nomad when using FX loop. Help?

[oliass]

I searched all over the board and couldn't find an answer to this question.

When I'm using the FX loop in my Nomad 45, the volume will drop waayyyy down and later come back up, then go down again, etc. When I don't have anything plugged in to the FX loop, it's fine. I tested the cables and they seem to be fine. Can anyone suggest a do-it-yourself fix for this? Any help would be greatly appreciated.

 

[Koreth]

Does it do this whenever you run any kind of effect in the FX loop, or just a certain effect or set of effects?

 

[nomad100hd]

it could only be ur FX, the jacks or the fx mix pot.

 

[Dolebludger]

I second Koreth's question here concerning checking out the individual effects as the first diagnostic step. A problem with one effect can cause just this problem. For example, I had the same problem on my Nomad 55, and discovered that my power supply cord on my Graphic EQ had become detached. The fix was to merely get the power back to the EQ. And if you have any battery powered effects in your lop, a dead, weak, of poorly connected battery is a likely cause.

 

[nomad100hd]

the fx loop circuit is always in the signal path on the nomad amp. the only mechanical parts are the jacks and the mix pot. so more than likely it's not the amp.

 

[R_ADKINS80]

My 5150II and my triple rectifier did exactly the same thing only when something was plugged in the loop. Turned out to be a bad fx loop preamp tube.

 

[nomad100hd]

Well on the nomad there is a solid state buffer sending the signal to the fx loop and a tube recovery stage. However also on the nomad the fx loop circuit is always in the signal path. The loop uses a switching jack on the send.

 

[oliass]

Thanks for the replies.

I haven't actually tried different FX in the loop. I've been using a TC G Major. I'll try something else and see what it does.

I'm not sure if it could be a tube because it was doing it with my old set of tubes and also now with the new ones.

 

[oliass]

Well on the nomad there is a solid state buffer sending the signal to the fx loop and a tube recovery stage. However also on the nomad the fx loop circuit is always in the signal path. The loop uses a switching jack on the send.

I'm sorry. I'm pretty clueless about the electronics. Does this mean it could be the amp?

 

[nomad100hd]

if it's the amp it's a bad jack, or mix pot, IMO.