sometimes transformer hum can (as Jax2 said) just be the result of loose mounting bolts, sometimes not. Sometimes its just how that particular tranny is. Toroidal trannys are often less susceptible. One other cause sometimes is DC offset, IIRC.
Tube Ampp Almarro low level hum
My Almarro 318B amp has recently developed a low level hum that comes and goes. I have swapped out all 4 tubes at one point or another and that does not change it. Once the hum stopped for a few days while I was breaking in a new paid (NOS) of 6C33C tubes. But it keeps coming and going. It gets a bit louder and then softer. If I tap the base of the amp, the hum stops. If I pick up the amp, it stops. If I knock the table where the amp sits, it stops.
I run the amp about 6-8 hours a day. Once a week I foget and leave it on all night.
Any ideas?
Thanks
Dan
I run the amp about 6-8 hours a day. Once a week I foget and leave it on all night.
Any ideas?
Thanks
Dan