Bare Knuckle Pickups Forum

Forum Ringside => Tech => Topic started by: TomW on July 01, 2007, 09:15:54 PM

Title: Reduction in volume of amp
Post by: TomW on July 01, 2007, 09:15:54 PM

Every so often I've been noticing that my amp suddenly goes quiet for a couple of seconds and then returns to normal volume. Is this a sign that the tubes need changing or is there something wrong with my amp?

Title: Reduction in volume of amp
Post by: Metal-Assmoney on July 02, 2007, 02:12:01 AM

hmm, it could be a number of things. the only way to really tell these things is to try and isolate the problem. i can give you a few steps to try and find the problem. if you do these in order you may be able to isolate where it is.

1) Check all the wiring in your guitar. jam a different amp for a few hours.
2) Try a different cable.
3) plug the line out of your amp into a computer and play for a bit. if the problem is still there, then the problem is in or before your preamp stages. if its not, the problem is in your power stages.
4) different speaker cable to the cab.

Title: Reduction in volume of amp
Post by: CUBE on July 02, 2007, 03:31:22 AM

try changing your power tubes

Title: Reduction in volume of amp
Post by: Metal-Assmoney on July 02, 2007, 04:36:26 AM

that can be expensive, and its a shot in the dark. he should really try to isolate what the problem is before taking a stab at it.

Title: Reduction in volume of amp
Post by: CUBE on July 02, 2007, 05:44:41 AM

your right.. whats a set of tubes cost like 60 bucks.
its does not sound like cables.
  i bet its a class A/B amp and when the push /pull happens its whats dropping the volume.

Title: Reduction in volume of amp
Post by: Metal-Assmoney on July 02, 2007, 05:56:32 AM

does your amp have a rectifier tube?

Title: Reduction in volume of amp
Post by: indysmith on July 02, 2007, 08:37:50 AM

my minimat does that if you have it on a ridiculously low volume. Try cranking it a bit? lol

Title: Reduction in volume of amp
Post by: HTH AMPS on July 02, 2007, 11:13:12 AM

volume fluctuations are one of the symptoms of output stage valves about to give it up - how long you had those valves in the amp?

one of the more common volume related problems occurs with effects loops - try plugging a patch cable between the send and return jacks when the volume fluctuates and see if that helps.  

lastly, it could be dirty volume pots - just try rotating the pots a dozen or so times around the range you tend to have it set at.

 :twisted:

Title: Reduction in volume of amp
Post by: TomW on July 02, 2007, 02:32:16 PM

I've tested all of the cables etc and they seem to be working fine so I think it probably is the tubes as they have never been changed and I've had the amp about a year now.
Anyone know of a good place to order tubes from? Are www.eurotubes.com any good or is there somewhere better?

Thanks for the help :)

Title: Reduction in volume of amp
Post by: Woogie on July 02, 2007, 03:42:22 PM

Hot rox or Watford valves

Title: Reduction in volume of amp
Post by: Metal-Assmoney on July 02, 2007, 05:36:40 PM

JJs from eurotubes are the best bang for the buck. i run em in my AT-100 and they kick ass, and with 12 tubes the retube only ran me like 150 bucks. from groove tubes it would have cost me $300.