Is something wrong with my amp?

Discussion in 'Amps and Cabs [BG]' started by Beefbass, Mar 26, 2001.

  1. Beefbass

    Beefbass Guest

    Feb 4, 2001
    Hello, this is my first post on talkbass. I have a question about my Peavey Combo 115. I thought maybe someone might be able to help me.
    The amp sounds really nice. I use passive basses, and I noticed on Saturday night, at the beginning of the second set, the sound seemed to fluctuate up and down momentarily. The master volume was up to ten, gain was at about one and a half, bass volume maxed. I bumped the gain up a little to two, and the problem went away-it never fluctuated after that.
    A friend who knows more than I do, thinks it may not be broken, because it never fluctuated while playing the set. He suggested lowering the master, and bumping up the gain a bit. He said that this amp might have a sensitive gain; setting it too low could cause this. When I tried his suggestion, it worked perfectly.
    Could he be right? I hope somebody might have an answer. I don't feel like hauling it back to the store if it's not broken.
    Thank you all very much, this is a great site.
  2. yawnsie


    Apr 11, 2000
    First of all, welcome to Talkbass, Beefbase.

    About your amp, I don't think that there's anything wrong with it - I'm no expert, but I know that it's very unusual to have the gain so low, and the volume so high. As far as I know, (though there's a very good chance I may be wrong...) gain controls the amount of signal being allowed through the rest of the amp, while volume controls the speaker. Maybe there's not enough signal to keep the tone consistent at that volume - the fact that the amp worked properly once you'd turned the gain up and the volume down seems to confirm this.

    As I say, I'm not especially knowledgable, but I'm sure someone will be able to confirm or deny this. But I don't think there's any need to haul your amp back quite yet.
  3. LowRanger


    Dec 24, 2000
    Your friend sounds like he may have pinpointed it. I had the same experience with a preamp/poweramp rig, I guess I was just running the master somewhere in its "grey zone," or perhaps the pot itself is bad. In the pot travel, there's a somewhat amorphous point between where there is some output, and where there is none.

    Good luck!
  4. embellisher

    embellisher Holy Ghost filled Bass Player Staff Member Supporting Member

    Welcome to Talkbass!:)

    I have a 20+ year old Peavey TNT 130, and the manual for it recommends setting the gain pretty high for maximum sustain, and then controlling the volume by adjusting the master volume control.

    Back when I used the amp all of the time, I would set the gain at about 7.5, and then the master volume would be anywhere from 2 - 7, depending on how loud I needed to be.
  5. Hey Beefbass, good to see you made it over here.
    Isn't this palce wild? So much bigger than the other place.

    Anyway the answer I was gonna give is just what
    Embellisher said; more gain, then just adjust the volume to the level you need. If we're talking about posting at this forum, you've got some catching up to do; I just passed my 100th post.

    If we're talking about hamburgers, you've got some ketchup to do!

    Sorry for that one!

    Welcome aboard!

    Mike J.( a.k.a ) The Mickster

    P.S. Question for anyone: I just took some photos of my basses, I have them on a Kodak disc --- How do I get them into the forum? I'm *NOT* a computer whiz. Thanks.
  6. I agree with all ov the above. The fluctuating may have been the noise gate (don't really know if there's one in that particular amp) kicking in. With a low gain setting, the preamp section may getting a very weak signal, but overall volume may be ok with the master volume cranked up. But with a low signal level in the preamp, it's built-in noise gate may kick in way too soon.

    Mike J.-- Put your pictures on the net and link to them from You could use Photopoint picture hosting ( I believe) to do this, or your own web page or whatever what's online. You CANNOT upload from your harddrive to! Talkbass doesn't have room for hundreds of posted pictures.
  7. Beefbass

    Beefbass Guest

    Feb 4, 2001
    Thank you so much everybody, for all your help. Believe me, I'm breathing a lot easier! You know what I did? I'm so used to the way Fender reccommends setting an amp(master cranked-use gain to control overall volume), I didn't realize that it might be different with the Peavey. Everybody who owns a Combo 115 says they're very reliable-the main reason for buying it(besides financial situation.)
    Peace everyone, I gotta go wipe the sweat off my forehead now!
  8. See that Beef, everything's O.K. You had nothing to lose, and everything to GAIN!

    Hey Joris, thanks for the advice on the photos.

    Mike J.
  9. You mean Fender tells you to set up your amp like that? That's just the worst advice you can give. No wonder why I dislike everything that is Fender. No offence to anyone personal...

    Mike, You're welcome. How's things going?
  10. Beefbass

    Beefbass Guest

    Feb 4, 2001
    I had a Fender BXR 400 head once, and thats exactly what their owners manual said to do if you want a clean sound. I never thought about it at the time, but the gain knob on that was always a bit touchy too.
    I noticed that Peavey prints it's specifications based on the gain being halfway up, master all the way up.
    Will be bumping up the gain quite a bit from now on.
    Thank you very much everybody for all your help. You guys helped me take a load off my mind.