Nomad 45 Channel 2 gone - help?

[jared]

My friend's Nomad 45 pretty much lost function of Channel 2. We're pretty sure it's not the volume or gain pot, which is entirely possible.

Could the loss of just one of the three channels be attributed to a tube problem? Or can we rule that out and say it may be more internal?

Thoughts appreciated.

 

[nomad100hd]

my channel 1 went out and it was a relay!

 

[Koreth]

If you've lost channel 2, but channel 3 works fine, I doubt it's a bad tube (though it doesn't hurt to check), as channels 2 and 3 share the same preamp tubes (V3 & V4). What do you mean by "pretty much lost function of Chanel 2"? Do you get no sound at all? do you get a thin, weak, useless sound, as if something somewhere was barely connected?

 

[nomad100hd]

the treble pot going bad could probably kill your sound i'd check all the tone controls as well. yes be more discriptive

 

[jared]

Channel 3 works fine so I'm thinking it's a pot or some pots. We've had them changed on his amp before so I had a feeling it might be along those lines.

I was trying to rule out a tube problem and it seems I've done so.

I do want to go back to the amp, though probably not until this weekend, and get a better idea of what's going on. Sound comes out but there's basically nothing there. Thin, weak, super low volume. I'll give each pot a check.

Thanks for the advice so far everyone.

 

[nomad100hd]

similar to my relay problem. it's ether a relay or one of the tone controls. probably treble control

 

[Koreth]

Sounds like possibly a busted pot. When I first got my Nomad, the pots were damaged and turning them could cause the whole channel to cut out. I'd find a good tech in your area, especially one recommended by Mesa/Boogie on their webpage if possible, and have said tech check things out.

 

[dodger916]

Sounds like possibly a busted pot. When I first got my Nomad, the pots were damaged and turning them could cause the whole channel to cut out. I'd find a good tech in your area, especially one recommended by Mesa/Boogie on their webpage if possible, and have said tech check things out.

I had a Nomad pot go bad on me too. I've heard it's a problem with these amps.

 

[nomad100hd]

does turning the amp on and off standby do anything to the problem?

 

[jared]

Well, he's using the amp in gig situations (alongside me) so on and off standby doesn't impact the channel. He just avoids the use of Channel 2 altogether and we wing it with Channels 1 and 3. Almost positive it's a pot or two, based on the prior replacement of pots and other's accounts. We'll need a stretch where he can sacrifice the amp for the sake of repair, which with some techs I've noticed, can take a while.

 

[MrMason]

Never rule out a bad tube; even if 2 channels share a tube, it's always possible for half of a tube to go bad (since tubes are dual triodes afterall). It's possible that one channel uses one side of a tube, and one uses the other.

 

[nomad100hd]

or you could order the Pots and replace them yourself its' not hard at all.

 

[Koreth]

Never rule out a bad tube; even if 2 channels share a tube, it's always possible for half of a tube to go bad (since tubes are dual triodes afterall). It's possible that one channel uses one side of a tube, and one uses the other.

While this is good advice in general, in the Nomad, the the exact same tube sections on the exact same tubes are used in the exact for same order for both channels 2 & 3. V1A&V1B (in parallel, gain stage 1)-> Gain pot -> V4A (gain stage 2) -> V3B (gain stage 3) -> V3A (Gain stage 4) -> Tone stack/controls is the signal path for both channels 2 and 3. The difference in flavors between channels 2 and 3 comes from the different component values before the gain controls and the different component values in the tone stacks. So if a bad tube or tube section was causing channel 2 to be weak or mute, the same behavior would be seen in channel 3 as well.

 

[jared]

This is all great stuff. Thanks guys.

Actually our drummer just replaced the pots last time when the solo pot went, and a few others I think were pretty shady so we did those too. He's a sound guy and really good with all that stuff. The amp is long since warranty, so we just get better repair time when it's one of our own! And the pots are inexpensive.

Now I wanna dig in and get the full story on what's going on with the channel.

 

[jared]

Was poking around and found my 2 month old thread here. Usual suspect for a Nomad. It was the Channel 2 treble pot. We have it working temporarily by wedging something in between the body and the knob so it has the effect of holding the knob as if it were pulled out. Until we have time to replace it, this will do. So, anyone having channel issues on the Nomads, it's probably a bum pot!

Replaced the tubes as well with JJ EL84 and the Doug's Tubes tone kit. Sounds like buttah.

 

[nomad100hd]

probably don't need to replace the pot just push the housing back together!

 

[pinata301]

I registered to this forum just so I could say thanks to you guys for the information. My Nomad 45 had the same problem with channel 2 and it turned out to be the treble pot.

 

[bgh]

I registered to this forum just so I could say thanks to you guys for the information. My Nomad 45 had the same problem with channel 2 and it turned out to be the treble pot.

How are you liking your Nomad? I have a Nomad 45 1x12 combo and love it! I bought it dirt-cheap at a Guitar Center (via telephone). It had some serious issues, but, GC address every single issue on their dime - including shipping. (Karl at the GC in University Park in Chicago was a super help in doing this).

Since then, I use this amp a lot and love it. The Nomad doesn't get a lot of love, but mine sure sounds good to me. It is a good amp to complement my Mark IV.

PS: Thanks for sharing the good news of how the Boogie Board helped you out!

Thanks for reading.