Needing help with AMP noise

[Charles Tilley]

l have a Session 400 with 15"BW that has hissing noise when the volume is turned up very loud. I know there are many that know what needs top be done to correct this and l would appreciate your comments. l am capable of installing my a modification if needed if l just know what to install.
A friend of mine has a Session 400 same as me and has no problem. In fact, when he plugs his steel in my Amp, the output volume decreases by about 30%.

Your comments will be appreciated

[patrick donovan]

If it does this without the guitar plugged in, I would suggest you replace the filter capacitors in the power section. If is is a 60 cycle hum this should correct it. Clean all the connectors with electronic cleaner and excersize them with a phone plug also make sure all ground connections are tight and solid.
If it does this only with the guitar plugged in, it's not the amp.

Hope this helps.

Regards, Pat
Donovan Electronics

[Jack Stoner]

Pat, from his description that sounds more like typical amp "white noise".

Depending on the model of Session 400, it could be several things. The older ones had discrete components in the preamp. The later ones had op-amps, etc.

It may be a voltage problem, but I'd look at the preamp first.

b0b - move this to electronics.

[Donny Hinson]

Right on, Jack! Either a bad op-amp, or maybe (in an older amp) a leaky transistor in the preamp stage.

[Mike Brown]

Charles,
I can assist with this, but turning the amp up "very loud" is not a valid test without an input. You would never use it this way. The amp "will" be noisy if the EQ controls and gain controls are turned up.

Please provide your settings and I will try this here in the Service Department at the factory. A mod kit will not repair the problem, but it may actually "enhance" the problem. The purpose of the Peavey kit is improve the overall voicing of the amp.

I invite you to call me toll free at the factory. I am here Monday through Friday after 8am CST. Let's discuss and take care of any doubts that you may have about your Peavey amp.

By the way, the Session mod kit can be viewed at "www.peavey.com" My number is 1-877-732-8391.

[Charles Tilley]

First of all,,,, thanks for the nice response which l really expected from the great guys that play and help.

Maybe l did'nt provide enough information about the problem and it's parameters but when l get back home from a funeral of my sister, l will post as much info. as l can.

Mike Brown, l very well may take you up on a direct contact on the problem Friday.

Thanks to all of you who have responded.

And they tell me that RVer's are the closest knit group. They have never met STEELERS have they?

[Charles Tilley]

l got home and started eliminating everything l could and may have found a problem. It may be my Alesis Quadraverb that is emmitting the noise. l went directly to the amp and got more volume plus less noise.

Anyone out there ever had an Alesis create noises? I'm still checking out the problem as l write this.

[Chick Donner]

I have two of the Quadraverbs, and they are EXTREMELY noisy boxes . . . they work well, and for bar and show gigs are usually acceptable . . . generally can't record with it, unless the studio has one hell of a noise gate . . . usually go straight to the board and use the studio effects . . . no way to get rid of the noise that I've ever heard of. Best suggestion(s) seems to be to go to a Lexicon MPX 100 or a Digitec box.

[Donny Hinson]

Charles, you HAVE to remember that when you have "stuff" between the steel and the amp, that that's the FIRST place you look when something goes wrong. Simple fact is, the more stuff...the more possibility for noise and problems.

[Charles Tilley]

Thanks for all the help. I have determined it to be 2 things.

1. The Alesis Quadraverb
2 A higher than needed setting of the Reverb on the Session 400 Amp.

Please close this topic as l believe the problem has been solved.