That's right, Howdy ya'll.
Haven't been here in many moons squared.
Hope you'all are doing well and I see we are still
alive and well.
What new has been happening?
What fun has been happening?
I see guys like WaltC and blue are plugging away.
+ 2 What the other's have said.
Including, that power transformer is beyond the end of its useful life.
The enamel coated wire in the transformer may have degraded to
the point where the heaters no longer work.
It may be time for a rewind or buy a new power transformer...
Don't feel bad brother. Sometimes I take years to figure out.
Sometimes you never do. Your just too close to see it and
you don't feel like messing with it.
Read up on the Dumble guy and the Trainwreck guy. Both them
had amps sitting around...Ken I think never messed with one of
I should have realized this sooner.
The replaced pot, the TremVol pot was damaged.
Don't know if the unit came that way or damaged in shipping
who knows. But when I got the amp it was in there and always
was causing problems, unbeknownst to me.
So a little bit of clean and removal along with...
I did the mods on a friends amp. It really made a difference along with a new speakers.
Unfortunately, I also told him I wouldn't keep the crappy output tubes in that amp.
He should get some good new or NOS and just suck it up and pay the money.
I think three to six months later he gave me a...
Here is the AC30 that I've got and gave up on and recently working on it
again. These are pics from the late 80s hand wired LTD edition from
what I can tell.
Interestingly I found some other pics of one on the net and it is slightly different than the with the GZ34.
To note these are the...
Yeah, your memory is pretty good, especially in dealing with
the definitive British amp. The tube numbering scheme would
make even Spock cringe though. I'll post a real treat for you
over on my thread.
I'm thinking the problem may be with the normal volume pot,
Center tab thru 220K connects to the 500pf cap at A17
Right tab connects to .047uf cap on A 26.
Is this a pretty standard issue with the AC30? (CD7 is there for fitting purposes, not soldered in.)
And the right side here...
I'll have to post some pics.
Trying to resurrect an old AC30. Not that old,
is the SS rectifier one.
Horrible hum, and pots/parts replaced prior...
...I'm trying to sort it all out here.
For now, this is where I'm at...
voltages are +-10/20 percent, in spec.
vib/trem vol and brillant vol...
Bias fine with no signal; my bad it has a load.
Also the amp is in spec during idle conditions. Then when a signal applied,
the one side will not balance up. All the componant parts test and
measure out fine. I also replaced the plate load resistors with new
600 ohm instead...
Gotta quick Ampeg Bias problem. The amp is within spec with no load.
.072 v on the power tubes and balances fine. I changed the bias sense resistors to 10 ohms.
So it is all happy until you run your test signal through it and it the bias goes to hell with 1/2 the output tubes...