Nomad 55: FX Loop = dead

[Riff Blister]

So, I'm going to sell my Nomad to a guy I work with. We are good friends so I want it to be tip top shape for him.
I just re-tubed it and last night I was making a check list of some of the bad pots I'm going to replace. I found three on the front end.
While I was at it I patched my pedal board into the FX loop and I got nothing but silence.
Another bad pot on the FX mix??? What else could it be?

 

[dr730]

did you put all new preamp tubes in? if not, maybe a bad pre amp tube for the loop?

 

[Riff Blister]

Yeah, all new preamp tubes along with the power tubes.
When I didn't get any sound I disconnected my pedals and hooked the back up to my Stiletto and that worked fine.
I actually went back and forth a few times. Nomad nothing, Stiletto fine. I'm going to order a pot for the mix and start there.
If that does not work I'll have to take to a tech.

 

[nomad100hd]

i modified my loop to series which bypasses the mix knob. There are no tubes in hte FX loop on the nomad.

 

[Koreth]

There is a tube in the FX loop on the Nomad. The 2nd half of V4 drives the FX return per the manual and per the schematic available on the Internet. Since a 12AX7 contains two triode sections, it is possible that the half of V4 that drives the distortion channels is good, but the half that drives the FX loop is weak or dead.

 

[nomad100hd]

your wrong dude the nomad does not have a tube driven FX loop. There is a tube stage after the fx loop as a recovery stage. The signal always goes threw the fx loop just bypasses the jacks and mix knob when nothing is inserted. So if it works without something in the loop it's either a jack or the mix knob.

 

[Dolebludger]

Perhaps when you bypassed the FX control pot, you missed something?

 

[Tommy_G]

Well, if the effects loop isn't tube, then it must be IC. Put a new op amp in.

 

[lerxst88]

either way the signal goes into a 12ax7 immediately after the FX mix pot save for a 470 ohm resistor. Im 100% sure because i just spent my afternoon series-modding my nomad and staring at the schematic.

the problem is when youre plugged into the effects loop? or when its not being used?

if its not being used: the jack for the send has a little contact that is closed when nothing is plugged in and open when you plug a cable in. it may have lost some of its tension. try to bend it back.

if it is being used: ive had effects loop issues where i wouldnt get any sound but just jiggling the cords coming out of the effects loop would fix it.

both are cheaper than taking it to a tech and worked fine for me haha

 

[Riff Blister]

Yeah, so anyway, I replaced the FX Mix pot and that did the trick.
FX loop works fine now.