#1
It's a really weird one, sounds like a low bit depth fire and it can only be heard when the standby swicth is off (so the guitar can be heard through it).
It doesn't get any louder or quieter when I turn any of the controls and it is still there when the guitar lead is plugged into the front.

Could it be a problem with the biasing?

Cheers
Main Gear:

Santiago S3 Spanish Classical
PRS CE22 Mahogany
Mesa/Boogie F-50 combo w/ G12K-100
Teese RMC Wizard Wah
Rothwell Switchblade
Ibanez FL-9
Visual Sound Liquid Chorus V2
EHX SMMwH
#2
Quote by guitaristclass
It's a really weird one, sounds like a low bit depth fire and it can only be heard when the standby swicth is off (so the guitar can be heard through it).
It doesn't get any louder or quieter when I turn any of the controls and it is still there when the guitar lead is plugged into the front.

Could it be a problem with the biasing?

Cheers


Sounds more like your output tubes have reached their best before date.
The fact the sound can only by heard with standby off (playing position) backs this up as the tube only makes the sound when B+ is applied. With stand-by on only filament (heater) voltage flows.
Try a new set, bias up and see if solves your problem.
#3
Hmm i only just bought all the tubes... Like literrally febuary and i've not used it that much.

I just swapped out the preamp tubes with the old ones and the same problem is there so it's deffinatly something to do with the harmas.
I'll give the company I bought them off a ring.

I didn't have it re-baised when i bought it cos there is noone around me who is qualified to do it.

EDIT: I just swapped out the Harmas with the old set of ENGL 6L6s (one of which has a fault) and it was glowing orange and sparking when I turned the amp on so i only had it on long enough for a check, but from the heat coming off it i can tell why i was having the problems before hand. AND the hum had gone completetly with the old knackered 6L6s... I shall be returning these Harmas I think, see what they have to say.
Main Gear:

Santiago S3 Spanish Classical
PRS CE22 Mahogany
Mesa/Boogie F-50 combo w/ G12K-100
Teese RMC Wizard Wah
Rothwell Switchblade
Ibanez FL-9
Visual Sound Liquid Chorus V2
EHX SMMwH
Last edited by guitaristclass at Jun 20, 2008,