June 28 2003 amp clinic
|This clinic was held on June 28th 2003.
This was the first clinic that was not held at a music store. This was something of an
experiment holding the clinic at my home. There were a few reasons to try this, the
biggest of which was to keep the clinic smaller, having all the folks show up at the same
time, so they could all see different amp types and interact with each other, and have a
less formal and rushed environment.
This worked out very nicely.
The mix of amps at this clinic was a nice mix with some really terrific examples of a few amps. There
were amps that performed really nicely, some that needed a bit of work, and others that were in
pretty sad shape.
First up to bat was Darren Stroud. Darren has Marshall DSL 100, and this was a very strong amp, but
running at 53.2 milliamps, about 81% idle dissapation. Darren likes the way it sounds, and did not
want to rebias, so a shorter bit of tube life and a bit more heat will be tolerated in the quest for his
John O'Donovan was up next, with a Marshall Super Lead 100. I don't know if he actually plays this
amp often, as upon opening the back, there were a number of modifications done, and one of the
four output tubes had no getter flash, was white with loss of vacuum. The amp would not even
power up. Due to the amps waiting, this was not a good time to start repairs, and repairs are not
really a part of the clinics, so I gave him some tech references and suggested that John have a
good tech give the amp a good going over.
Darren and John were the first two to arrive at the clinic, so while things were quiet, they were able
to play the Victoria Sovereign and were the only folks that got the "upstairs" tour where some of the
more interesting amps are located. The 1/2 kilowatt 200+ pound, 8 rack space Rivera monster lives
up stairs ... not too many folks have seen a tube setup this large.
Steve Pettit - this guy was the reason I had to break out the camera, and even with my bad photo
skills, this is a bit of proof that there are great deals out there. Steve had three amps. The first one
that caught my attention was a Groove Tubes S-75 that he bought at Guitar Center at some sort of
blow out for $299.00. The amp had original USA GEs in it, and cowhide covering. The cowhide
option alone was about a $300.00 DEALER COST upgrade! He asked me about the history of the amp,
and I did not know, but told Steve to call GT Monday and talk to Rick Benson, as Rick knows all this
sort of stuff. This was not the only surprise from Steve. A 1996 Matchless Brave in Turquoise Tolex
in amazing shape was another of Steve's amps. (Checking with Phil at matchless today, he said the
transformer may be from 1993, but the amp was most probably made in 1996). This was another
"steal" at a GC blowout. This amp was played by a lot, and I used it as an example to illustrate just
how terrific a simple front end design can do so much for tone and articulation. Steve also had a
Bogner 101 that we did not have tome to get to .... next time Steve.
I have a few photos below of Steve's S75, and some of a few of the group.
Andy Jackson - 1963 Vox AC-30 Top Boost in 9.9+ condition, all original. Why not "10"? One of the
original three vent grills is missing. I gave Andy some ideas on where to get a replacement. The
amp tested out great, played great, and looked great. It's a winner!
Paul Peterson - Okay .... no repairs are to be done at the clinic, bit when you have a sad Marshall
1987 sitting there, only putting out 7 watts max, and the owner sad as to it's sound, sometimes you
just HAVE to pull the chassis and not just the back, to see why this is happening, especially when th
amp is so clean in every other aspect. No sceen voltage on V5 .... and voila, the screen resistor
had come loose from one of the pins. There was no mechanical connection on the screen resistors,
just tack soldered and hopefully left to hold. Cold solder joint here, and a bit of age, and this is what
can happen. Maybe this amp was built on a Friday afternoon in it's day, although everything else
looked great. In any case, the problem was fixed, and we were lucky as Ludovic Pierson had a set
new GT E34LS #6 tubes around, and gave Paul a great deal ... I biased the amp up and there was no
charge for that or the repair, so Paul ended up with a super amp at the end of the day just because I
am a sucker for non master volume small box Marshalls! Happy Playing Paul!
I did not get a sheet on the PERFECT Fender Super Reverb. There was nothing to do - this amp had
been kept up, biased right, blew everybody away with it's tone and feel. I guess we all got wrapped
up into what a classic amp can do, and the magic it has with any guitar type. I ended up pulling out
Strats, Teles, PRS, we had Les Pauls and all sorts of things to play with, and this amp was one of the
hits of the clinic. .... maybe THE hit of the clinic. Sure, the AC-30 was pretty amazing, it would be a
tough call. .... maybe we all need one of each of these! I am pretty sure this was Andy Jackson's
amp, but may be mistaken. If I am correct, then he does not have to make the choice between the
AC-30 or the Super Reverb, as they are BOTH his!
Oh .......... did I mention the Gold Top Les Paul with P90s? Some of the guitars that were
brought by their owner's were every bit as cool as the amps!
Steve's GT S75 in cowhide above and below. This picture is mostly here for Aspen and
Rick back home at Groove Tubes, as they may know a bit of this amps history. Not a lot
of these went out in cowhide.
I gave a bit of a talk on some of the design aspects of this amp, and some bit of
background on it's designer, Red Rhodes. I went into how this amp is a true class A/B or
true cathode biased amp in Class A Narly or Class A Normal. Amps today with a switch
for pentode/triode mode do nothing more than turn off the screen voltage, and some
folks confuse this with Class A or cathode biased amps. The way this is done on the
S-75 was very costly, and not just a simple switch.
I also talked a bit on how Red invented so many of the things we take for granted today,
or designs that others take credit for in a few cases. Red was a humble man, and was
not the sort of fellow that had any sort of ego or anything to prove to anybody. You
have all heard him play, no matter what your age. Red was on countless recordings as
one of the finest steel players of all time.
Common items that Red created were things like the channel switching amp, parallel
effects loop, Velvet Hammer pickups, and what GT calls their PR928, also known as the
Ruby Tone Bone, or THD Yellow Jacket to name a few things. Check with folks like Paul
Rivera or Randall Smith on what they have to say about Red. He taught a lot of folks a
lot of things, and we all miss him very much.
By the way, Rick Benson at GT has all the info on this amp - it was known as "Norman 2"
one of three made special order with Brazilian Imported Cowhide for these three amps.
In closing, I'd like to thank all of the folks at the clinic. I will be doing this again in the
future, and I think a half a dozen folks was just right. I am sorry to the folks that I had to
put off until down the road, but I wanted to keep this smaller, and it turned out to be a
good call on my part if I do say so myself. This gave us all time to experiment and
interact, meet new folks, and have a great time for what turned out to be about 5 hours
in the end.
In the future I will be doing a clinic at True Tone Music that will be by invitation by ken
Daniels, and also another clinic at my own home again.
Thanks to all of the folks that attended.