#1
I searchbard, found nothing.
My Marshall is making this odd noise when I have the volume on my guitar rolled back slightly, or my overdrive pedal is off. The best way I can describe it is when I hit a powerchord the amp sounds like its dying, the distortion sounds weak, and the chord quickly fades away. If I have the volume on my guitar all the way up, however, I don't have this problem and I'm 100% sure it's not the guitar.
I realize this is an extremely hard thing to describe, but I figured it was worth a shot to ask.
I AGREE
#2
Have you checked the tubes?
Guitars: Fender FSR Standard Strat, Squire Affinity Strat, Epiphone Nighthawk
Amps: Vox AC15C1, Roland Cube 15x, Peavey KB-1
Pedals: Digitech RP355, HD500, Joyo AC-Tone, EHX Soul Food
#3
I would have 0 idea how to check the tubes, is there any safe way to do so?
I AGREE
#5
It's a 2003 model, being the re-issue. And I'm not sure on the amps history or its upkeep prior to me owning it.
I AGREE
#6
How long have you had it?
Guitars: Fender FSR Standard Strat, Squire Affinity Strat, Epiphone Nighthawk
Amps: Vox AC15C1, Roland Cube 15x, Peavey KB-1
Pedals: Digitech RP355, HD500, Joyo AC-Tone, EHX Soul Food
#8
Were the tubes replaced any time recently? That makes me think it's a preamp tube.
Current Gear:
LTD MH-400 with Gotoh GE1996T (EMG 85/60)
PRS SE Custom 24 (Suhr SSH+/SSV)
Ibanez RG3120 Prestige (Dimarzio Titans)
Squier Vintage Modified 70s Jazz V
Audient iD22 interface
Peavey Revalver 4, UAD Friedman BE100/DS40
Adam S3A monitors
Quote by Anonden
You CAN play anything with anything....but some guitars sound right for some things, and not for others. Single coils sound retarded for metal, though those who are apeshit about harpsichord probably beg to differ.
#9
That same thing happened to me once. not with that amp, but it was a wire not set right in the pickup switch. a djustments to that and i was all good. You try your guitar on other amps and messing with the switch as well?
~~~...:::My Gear:::...~~~
~.:.ESP LTD H-1001FM.:.~
~.:.Peavey Vypyr 15W.:.~
~.:.DigiTech RP355.:.~
~.:.Roland MicroCube.:.~
#10
I couldn't tell ya the last time anything was replaced, but I'd imagine everything is stock. Preamp? I'll definitely look into that then, arent those cheaper then the EL34s?
And yes, I've tried various guitars through the head.
I AGREE
#11
Yeah, preamp tubes are usually 12 ax7's, but I'm not sure what they put in jcm's.
Guitars: Fender FSR Standard Strat, Squire Affinity Strat, Epiphone Nighthawk
Amps: Vox AC15C1, Roland Cube 15x, Peavey KB-1
Pedals: Digitech RP355, HD500, Joyo AC-Tone, EHX Soul Food
#12
Quote by kutless999
Yeah, preamp tubes are usually 12 ax7's, but I'm not sure what they put in jcm's.

12AX7's.
Current Gear:
LTD MH-400 with Gotoh GE1996T (EMG 85/60)
PRS SE Custom 24 (Suhr SSH+/SSV)
Ibanez RG3120 Prestige (Dimarzio Titans)
Squier Vintage Modified 70s Jazz V
Audient iD22 interface
Peavey Revalver 4, UAD Friedman BE100/DS40
Adam S3A monitors
Quote by Anonden
You CAN play anything with anything....but some guitars sound right for some things, and not for others. Single coils sound retarded for metal, though those who are apeshit about harpsichord probably beg to differ.
#13
Buy a single JJ 12AX7 (ECC83S) and try it in each position in turn until the fault disappears. If it doesn't it isn't the preamp tubes. You should always have at least one spare anyway so it's money well spent.
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