Peavey nashville 400 question

[Ron Scott]

I have had this amp for many years and just started to get this loud noise coming from it while playing and I can turn down the volume, pull the cord on my guitar and the only way it will stop is reverse the polarity. Now I can leave it where it is at and the next time it does the noise then I put it the other way in Polarity. Any suggestions would be wecome. It does not do it all of the time when I play and my playing is done just at home and in my music room. Thanks Ron

[Curtis Alford]

Ron,
I would think you have either an appliance motor or the polarity in you house crossed. Motor caps/ start/run will some cause polarity problems. Also dimmer swithches and speed controlers for motors will cause this affect.
Get a polarity tester and check all you outlets in the building and your earth ground.
Curtis

[Ron Scott]

I have checked all these and it is a new home only 6 years old and I had it built. I have played my guitar here for 6 years and never had this happen before. It is a large hum and does not happen all the time. I am still trying different things to resolve the problem but it does not do it everytime I play. Thanks for your idea...Ron

[Ron Scott]

I have checked all these and it is a new home only 6 years old and I had it built. I have played my guitar here for 6 years and never had this happen before. It is a large hum and does not happen all the time. I am still trying different things to resolve the problem but it does not do it everytime I play. Thanks for your idea...Ron

[Stephen Cowell]

use a short guitar cord to bypass the effects loop/pwr amp out/pre in loops... these switching jacks get dirty and cause problems. Try banging on it next time it's in failure mode... got the crunchies? There's an intermittent connection somewhere.

[Ron Scott]

Don't use the effects loop and the cord is short. I do use a DD3 for delay and amp reverb. Thanks Ron

[Billy J Barbour]

Turn your reverb all the way off see if you hear it then.My 400 started doing the same thing and i had it checked and it was in the reverb pot where the springs are located in back of amp.

[Ron Scott]

I'll try that but it does it so few times it is hard to know when it happens but I'll leave it on and when it starts then I'll turn it off. Thanks Billy. Ron

[Stephen Cowell]

Sorry I didn't see that you misunderstood my suggestion... Your effects loop jacks may be dirty. Even if you don't use the loop the jacks are important... they make a critical connection between your preamp and power amp even when unplugged.

You can fix this by using a guitar cord as an 'effect'... plug it into the send and the return. This bypasses the switching jacks with a hard connection. This is the most common failure mode for Peavey amps.

[Ron Scott]

Thanks Stephen, I'll also try that. I really appriciate the suggestions guys....Ron

[Tony Prior]

Not to worry..most likely the connectors and jacks are dirty or just have corrosion...we are talking about amps that are in the 20/25 +/- year old range now

Inside the amp the Connectors need to be cleaned, the chassis Reverb connector needs to be cleaned, the Reverb tank connectors need to be cleaned, all the jacks on the chassis need to be cleaned by slightly burnishing them...especially the effects loops...

This is very common on the PV amps...

[Ron Scott]

Thanks Tony and all the guys who answered. I did not know that and I have had this Amp about that long too. I used to have 2 of them and when I lived near Branson Mo I sold one at The steel show there....Thanks Ron

[Ron Scott]

I did turn the reverb off when it did the noise thing again and it went off, so I took the whole electrical Chassis out and used electrontic spray and cleaned it all and the problem went away... thanks Tony,Curtis,Billy and Stephen for your great advice. Ron