Intermittent Hum

S

Sacha

New member
I noticed that I have a hum with my Herbert now, more then before. It seems to start out fine and then once the amp warms up a bit the hum gets way louder.

I just changed the power tubes, they seem good and are biasing fine but could they cause this? I swapped preamp tubes as well and it didn't seem to make any difference.

Thanks for any suggestions! :rock:
 
Pull one pair after the other (1,6 - 2,5 - 3,4) and listen if its caused by a pair. If your cab is 16 Ohm, use the 8 Ohm out instead (with one pair pulled). If your cab is 8 Ohm, use the 4 Ohm speaker out.
 
i'm getting a very similar problem with my einstein .
after the amp has been on for a while , theres a "click" and then it starts humming .

at first i thought that it was something in the studio where we rehearse that was turning itself on/off ( like a fridge ) that the amp was picking up .
however , today i noticed that it also does it in my home studio , and there is nothing in there that the amp could pick up .

how can this be remedied ? :confused:
 
duesentrieb":2e3d3 said:
Pull one pair after the other (1,6 - 2,5 - 3,4) and listen if its caused by a pair. If your cab is 16 Ohm, use the 8 Ohm out instead (with one pair pulled). If your cab is 8 Ohm, use the 4 Ohm speaker out.
Click to expand...

Well thanks again Olaf, the new power tubes where the problem! :doh:

I put a new set of Winged C EL-34 in there and it's all nice and quiet again.

The tone is a little different but very nice, I liked the Rubys as well but the performance on the last set sucked. The new ones are a little more slender on the low end and a bit more smooth, but I tweaked my settings and it sounds KILLER.

:rock:
 
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