hey john,
sorry for the pain with the pics, 40 some photos, didn't know
a better way to share them. I have made progress again today,
I redid the grounds on the 2 volume pots, and also reflowed
the solder on the center tap connection. This time I fixed
something and the hum was cut in half. I think there is gonna
be little improvement from here considering the PT itself is
humming! I put a screw driver on it and could feel the vib
through the plastic handle! I have seen this before, maybe I
can balance the secondary high voltage winding, perhaps?
ever heard of this? Seems like you could measure the voltage off
each leg of the mains and see if they are balanced.....
I hate to take my amps to techs, I have spent the last 5 years
learning bout tube amps and building probably 2 dozen, 20 of
those from scratch. Old vintage stuff is a totally different
animal, I have no problem trouble shooting my scratch builts,
they are basically new. big diff compared to the insides of
a 50 year old tube amp, all the dust and goo and corrosion,
no wonder the thing was humming! ;^)
Anyways;
It is much better now, not perfect but MUCH better. If I get
a hair up my ass someday I may try to rewire the heaters,
but at this point I have done lots of work and the amp is
cranking. I retentioned and cleaned power tube and recto
sockets, have touched every section of the amp at least
once. I will live with it for a while, now I can mic it without
introducing a ton of hum into our PA at church. I totally
isolate my guitar amp, face it up against a heavy stage curtain
and there are sound absorbing materials sort of behind it that
keep the sound from front of house. I usually use close back
cabs, but I am digging this amp right now. I put lots of my
guitar in a dedicated monitor at my feet, I can really hear my
guit without blowing teh vocalists faces off.
thanks for your help it was appreciated.
peace,
chris dansdill