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.
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...
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...
I've looked around and I'm trying to get some Hot Rod deluxe
amps for kids at my school. I've gotten grants from people,
little kids rock, Quincy Jones Musiq Consortium, and The
Dallas Foundation. You can check out the projects here:
Checking out the mods for the SVT some of the following questions
From the Tube Amp Book (4.1 ed, p. 278) and (Deluxe Revised ed, p132)
Discuss changing the the resistor values of R6 to 220K, R7 220K,
for use with a 12AX7 tube. However, both books show a change to
Wondering if a couple of y'all could help out some kids.
This is for a great cause, turn inner city kids to music,
not drugs or gamgs. : ).
Best of all, Quincy Jone Musiq Consortium matches your gift!
Check it out from the following NEW link...
I've got this Ampeg B-25 that is giving me fits.
Anyone have an old service manual for this amp?
I've got the schematic, pasted in the amp....
just about everything checks out on it
from the voltage perspective.
Pre amp isn't functioning properly
I think in the PI and right before it.
Anyone have any dealings directly with Jim Bergantino about
I've had some speaker and crossover issues with a product
of his. The original Bergantino speakers in the cabinet were
defective. Mr. Bergantino refused to warranty the original
speaker because I was not the original...
Lucky me, I've got one of these.
It is a late 60s, thin wire, silver face twin reverb.
It is a real HUM dinger. argh!
Been through caps, all electro's all around,
that helped, some.
Isolated to the power supply, with only the
PI tube, and the PI feeder cap removed.
Heater voltage is...
..... Third amp this month.
The vaunted blue mallory hot dog caps, taking
a slow death and ruining your tone.
Final couplings...eating your tubes and output trannies.
Pre amp, giving you that weak, thin, chit tone
with the virtual absense of bass in the amp.
Early fender black face amps...
I'm curious y'all...
As to why the checkered history of these amps?
Ones that I've encountered typically have three
types of caps...
Some with the following types of signal caps:
Vaunted yellow mustard caps
Medium yellow box caps
Crappy green thin caps
These amps are consided one...
You've seen the pics...nothing worse for a little guy to get stung
first by product that had to be removed from amps, but also to
suck up about $170 in defective product of what CE Dist refuses
to stand behind.
You think beta testing is bad, try having to pay for "production"
parts that have...
The mystery amp thing got me thinking....
Couple of weeks wiring an amp, covering it with goo... $ 6,000
Couple of months of pain staking, hand built detail... $ 4,000
No, that is not a mirror top, that is hand rubbed aluminum!
Sorry folks it took me longer than I had hoped.
Here are the pics of the leaky CE Caps, never installed.
They are physically leaking the electrolyte all except
the one on the right, which does not work, i.e., open.
If you buy these you are stuck. AES does not stand by their products...
I finally got around to taking some pics of that Hiwatt I've been
telling you about. It is a DR504.
Here was the "First" sign...
Then there was this "Other" sign...
Now take a deep breath and hear,
...it's only just begun:
Born under a bad sign:
More of the really...
In keeping with the spirit of TGP and knowing how some of you have
a fit about gutting an amp and rebuilding it.
We can do this a cap at a time!
You make the call!
The amp is a 1966 Ampeg Model J-12D Jet.
The amp hums like crazy and the tremolo doesn't work.
So far I've done the...
Well for some reason my logic has failed me.
I'm in the middle of moding the bias circuit on a
100 watt sound city amp. But now I can't recall
after I add another cap and another diode,
where those should all be wired to.
I know I'll have two caps in series where the
existing cap is...
I've been tracking this down for the last couple of weeks.
An intermittant sh*it sound coming from this vintage amp.
You'd play then after awhile it would get all weak and distorted.
After taking my time and undoing all kinds of mods done to the amp
it still did this...intermittantly.
Which would be the best candidate for implementing power scaling?
Kevin you hang out here, which would you choose?
None of these are prestine nor collectable per say.
I'm thinking the Twin Reverb or the Dual Showman Reverb
because they have more power to begin with and could