nashville 400 intermittent volume drops

Charles Bell · Post by **Charles Bell** » 21 Sep 2018 7:22 pm

anybody have this issue: playing at stage volume, the sound will suddenly drop way down in volume,while sort of crackling a bit. sometimes i'll even instinctually give some more volume with the pedal, only to have the signal come back full volume but now super loud with the pedal wide open. happens with the molex reverb connector connected or disconnected, happens with the steel plugged directly into the amp (no volume pedal). it's been through peavey's shop and a local fender liscensed amp repairman. both tickets say tested and working fine...anybody had this problem and beat it? how?

admin · Post by **b0b** » 21 Sep 2018 8:05 pm

This is a long shot but ... check your phone plug connections. I was having a similar problem a few weeks ago and finally traced it to a 1/4" plug that was manufactured too short. It didn't fully snap into the jack. Could happen anywhere in the signal chain.

Donny Hinson · Post by **Donny Hinson** » 22 Sep 2018 4:55 am

Probably just a bad/dirty jack. Spray ALL the jacks, front and back, and then insert/remove a plug quickly from each about a dozen times. If that has no effect, then it could be a dirty volume or tone control. Howevever, spraying the controls requires removing the amp chassis, so be sure you're aware of the issues involved with that.

Note that the "dirty jack" issue isn't just an amp thing, it can also extend to EFX and volume pedals. Try different cables, too, whenever you're having intermittent problems.

Ronald Sikes · Post by **Ronald Sikes** » 22 Sep 2018 8:01 am

I have a NV400 thatâ€™s been losing volume also. I think I figured out itâ€™s a dirty volume pot.

ajm · Post by **ajm** » 22 Sep 2018 9:29 am

As Donny said, bad/dirty jack.
But it could be any jack, not just the input.
I'd clean them all.
- Input (all)
- Effects loop
- Speaker
- Any others

Also, as was said, the volume pot.
And once again, I'd do them all.

For someone with no electronics experience this may seem like rocket science.
It's really not.
If you have someone that knows how to do it, and will show you how, then you can do it yourself from now on.
And as a benefit, you can also do anything with a pot or a jack as well.
Guitars, effects pedals, etc....

As a matter of fact, there's probably only about a bazillion Youtube videos showing how to do it.
All we need is one good and hopefully short and to the point example.

Michael Brebes · Post by **Michael Brebes** » 22 Sep 2018 11:59 am

If you are not using the Effects In/Out for your volume pedal, it could very well be the switch on the connector when there is no plug present. An easy way to check it when the problem is occurring is to plug a cable from the Out to the In, which will bypass the switched connection.

Bill Terry · Post by **Bill Terry** » 24 Sep 2018 8:44 am

Agree with ajm..

The molex connectors (which includes the speaker if I remember correctly) are notorious for requiring cleaning periodically. Sometimes just unplugging and plugging in again a few times will take care of it.

Norm Fletcher · Post by **Norm Fletcher** » 29 Sep 2018 12:43 am

Had an interesting fix of a similar problem. As a solid state amp with large power transistors heats, old solderjoints also expand and have semi-open connections around the power transistors. We were able to treat what was a similarly frustrating change of output power by simple reflowing the solder on the main power transistors. Not for the faint of heart, but it cured our problem.

Charles Bell · Post by **Charles Bell** » 29 Sep 2018 6:38 am

as if there weren't enough points of failure to check, i'll add another to the list: in this case, it seems to have been the speaker causing the problems. at the repair shop on the bench connected to a tone generator, if we lightly tapped the speaker cone (simulating excursion) the volume would drop just like i described earlier, tap lightly again signal came back strong. i put an eminence double t 15 in last night and so far zero problems..i have two rehearsals and a show this week, lots of opportunity to field test and be sure..i love the sound of these amps- of the 4 (or 5) i've had, this is the first with any issues.

chuck abend · Post by **chuck abend** » 2 Oct 2018 7:34 pm

I have serviced lots of peavey amps.The power amp in contact in the rear chassis jack can cause the problem.
exercise it and clean with contact spray .
Chuck

Bob Hoffnar · Post by **Bob Hoffnar** » 2 Oct 2018 7:53 pm

Michael Brebes wrote:If you are not using the Effects In/Out for your volume pedal, it could very well be the switch on the connector when there is no plug present. An easy way to check it when the problem is occurring is to plug a cable from the Out to the In, which will bypass the switched connection.

This fixed the problem for me when I tried it.

Mitchell Smithey · Post by **Mitchell Smithey** » 2 Oct 2018 9:34 pm

I would try putting a jumper between the pre amp out and power amp in jacks as suggested above. I leave one in all the time. Those switches are hard to adjust even after you clean them.

Mike Brown · Post by **Mike Brown** » 3 Oct 2018 8:58 am

Order from your authorized Peavey dealer or direct from Peavey by calling toll free in the U.S. at 1-877-732-8391, ext. 816.
https://peavey.com/products/index.cfm/item/904/72029

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nashville 400 intermittent volume drops

nashville 400 intermittent volume drops

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