Kelley Amp Repair (CC: AGA) long
Travis Bickle
The following is a copy of what I sent to Jim Kelley this AM. It
represents an example of what can happen when you take a rare vintage
amp to a tech for repair. The 4 techs discussed here all felt that they
were "right", and everyone is was "wrong". What do you think?
Paul
*******
Subject: Kelley Amp Transformer Repair
Date: Wed, 06 Dec 2000 10:34:20 -0500
From: Paul <XXXX.XXX>
To: Jim KelleyXXX.XXX
Hello:
Jim, please pardon the intrusion, I emailed you previously regarding one
of your amplifiers. I am the guy with a 30/60 Reverb Combo that was
having problems. I outlined what was happening at that time, since then
much has transpired. Permit me to share with you a thumbnail (a long
thumbnail). I think that you could offer assistance at the point where
we are now (December 6, 2000).
Here's the litany of what I have gone through with this amp since July
1998:
Playing amp, sounds flat, lifeless. One day, amp goes "poof", blows
fuse and is dead. Tech # 1 ("Larry") replaced one of the Sprague cans
with 4 photo-caps wired together. Ears say tone not right, tech #2
("Tim") replaces tubes and re-biases. Fuses blowing, tubes not matched
closely, and ears still say tone not right. Enter tech #3 ("Jim"), who
goes over the entire amp and declares it "OK". He installs (without my
permission) 4 individual screen grid resistors, saying it would
"stabilize the output tubes, and not affect the tone". Now it sounds
downright BAD. I contact you, you offer some suggestions, I find
another tech, #4, Joe Barden, the noted pickup maker who is also an amp
tech. He says he "knows" the Kelley amps, keep in mind, all of the
previous techs have never seen one, except of course for mine.
Here's where it all starts to get crazy. Joe goes over it, and really
takes it to town. Rebuilds the power supply with "better components",
removes the 5 (yes, that's right) screen grid resistors, apparently
Tech #3 didn't remove the original from the circuit , he puts it back
to stock. He lowers the value of the output coupling cap calling it
"The Ken Fischer mod" to clean up "unnecessary sub harmonics". Then he
tells me that the Output Transformer is "arcing and blown" and needs to
be replaced. He says that he has a part from new sensor, a center
tapped unit that "matches the original very closely". After installing
this new OT, the amp will no longer take 6V6s. Or, to phrase it more
appropriately, 6V6s cannot take the amp! He measures 520 volts on the
plates, it smoke balls a couple quads, so rather than burn up tubes, he
says "forget it, let's set the amp up for either a pair of 6L6s or
better yet, EL34s". I say what the hell, go for the EL34s. In the
process, he changes the bias supply to "to accept any kind of tube" and
the bias control "to be less hair trigger".
I get the amp back, it sounds pretty good, not like a Kelley, more like
a big loud clean amp. I could live with that, having been told that the
amp was "dead" by Barden, but now, with the new OT, I CAN'T GET THE
CHASSIS BACK IN THE CABINET!!. Exasperated, I call Barden (this was
just last week), and he is very matter of fact and disavows any
responsibility for it. I measure the new OT, it's 1/2" taller (hanging
upside down), no way it will fit. He basically said I was on my own. At
this point, I don't know what to do, but I can tell you, I won't be
doing any more
business with Mr. Barden.
On Monday December 4th, I emailed Andy Marshall of THD, a nice guy who
is forthcoming with information. He said that the original OT on the
Kelley had a different primary impedance, and that the circuit as
configured would put that much (520) on the plates but that the
impedances in the OT keep the 6V6s from frying. He suggested that I have
the original, which Joe returned to me, repaired or re-wound. I called
Plexi-palace at his suggestion, they specialize in vintage restorations,
and are FANATIC about "un-modifying" amps, putting them back to stock
and as they were originally intended. They will work on the amp, tech's
name (#5!!) is Craig. Although he has never seen a Kelley, he does have
a schematic that he will strictly adhere to. He said that they send the
transformers out to Mercury Magnetics for blueprinting and re-winding,
that they specialize in custom, unique jobs...
So...That's where I am with it. This thing is packed up to go, I was
wondering if you had the right specs on the transformer I could pass
along. Also, if there was a better schematic than the one in Aspen
Pittman's book (4.1 ed.) that would help too. This amp is serial number
203. Even better would be another original Output Transformer, but I
would imagine that they are hard to find at this point...
Thanks for listening Jim. Any assistance you could offer would be
greatly appreciated.
Paul
--
Remove "No Spam" when replying
Bob Sweet
transformers for him. Email me and I'll try and find it. The last time I had
talked to him (89-90) they where charging $120.00 for that tranny.
If all else fails try calling that number given in the Pitman books for
Kelly amps because he's the guy who gave me their number (if he's still in
business).
--
Bob Sweet
Sweet Sound Electronics, Inc.
Coral Springs, Florida
http://www.sweetsound.com
biasbros
"Travis Bickle" <unawrt...@yahoo.com> wrote in message
news:3A2E7532...@yahoo.com...
> Hello:
<Major snippage>
> Thanks for listening Jim. Any assistance you could offer would be
> greatly appreciated.
>
> Paul
>
Wow, man, you have been through the mill on that one. Well, I hear a lot of
positive stuff about Plexi Palace's work and Sergio at Mercury Magnetics is
the MAN.
Good luck, I hope it all comes together. Let us know the outcome.
Roy