Most cheap combo amps don't have any headroom built into them. I have a Laney 30w bass combo; never use it anymore but I still have it. It blew very soon after buying it years ago & I found that it had a speaker rated at 30w in it I switched it for a Celestion 10" 60w & it's been good as new ever since.
Is it safe to assume when you say it rattles that you've picked it up & given it a shake to check there's nothing loose in it that louder vols. are rattling about in the cabinet?
Also that you don't get it with headphones plugged in, or through the headphone? Also assuming here that it has a headphone jack?
Nope. No headphone jack. Good idea though.
I also don't hear anything rattling around inside when I shake it. This thing weighs a ton, so actually picking it up and shaking it is out of the question.
I don't ever want to mess with the guy who can pick this up and shake it, that's for sure.
The following observations might aid someone helping me isolate the problem:
I earlier described the problem as "rattling" - I probably should have used the word "buzzing". At times, it's a more accurate description of the problem.
- The Amp has 2 Inputs (Low Gain & High Gain) - the buzzing is more prevalent when using the High Gain Input
- If I activate the Post PreGain (Punch), even at 30% volume, I start to hear the buzzing. The Pre PreGain (Bright) doesn't ever seem to affect the sound.
- Equalization - the Low Frequencies seem to activate the buzzing.
- I always use an MXR M80 DI prior to the amp - I've removed it on occasions just to ensure that the problem still persists. It does.
THIS MIGHT HELP SOME:
- This amp has a Crossover section with 1/4" "High Out" and "Low Out" jacks, which should allow me to bi-amp
- This amp also has a Patch section with 1/4" "PreAmp Out" & "PowerAmp In" jacks (probably useless in this test)
Honestly, I don't know enough about this bi-amp stuff, but I'd imagine that I can use the Crossover outputs to connect another cabinet (or another combo amp).
I would never do this without being reassured that I'm not going to blow up more equipment. I've read the specs on my amp, and the description of the Crossover Section does not give me enough confidence to try this myself.
I have a few smaller combo amps available (SWR LA12-60W & a Behringer 180W combo) to test with. I'd hate to damage the SWR.
I also have a 300W powered monitor that I could use.
I do not have a cabinet at home.
Any suggestions before I disassemble the amp?
Thanks,
Steve