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Gerald Weber Signature Amp
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Quantity in Basket: none
Code: KEN0103-GWSA
Price:
$7,995.00
Shipping Weight: 0.00 units
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The first part of my career, during the 80's and the 90's, I built classic Western Electric circuits and refined them. I also serviced and overhauled virtually every amp ever made (about 12,000 of them). I manufactured my own line of amps, speakers and guitars; and even built another world-class amp design, created by an eccentric New Jersey amp designer. During those times, I had always fantasized about designing and building an amp that was a breakthrough in amp design - something that was beyond what had ever been achieved. - Gerald Weber
INCLUDES ATA FLIGHTCASE!
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Introducing
a breakthrough in amp design and construction: The Gerald Weber Signature
Amplifier. No guitar amp has ever been made with such attention to
detail and attention to tone. It features the best sounding circuits (all unique
to this amp), the best sounding components, the best sounding transformers,
the best sounding cabinet style, the best sounding cabinet wood, and the best
sounding speakers.
While the looks of this amp might make you weak in the knees, a peek at the
innards will definitely take your breath away. The construction goes beyond
what has ever been done in guitar amplifier construction. The black epoxy laminated
glass component board (Garolite) is so thick, there are not turrets sold that
are long enough to be used; therefore, I had to have custom-made turrets. You
may have seen this type of turret construction technique as it was done on high
quality Altec Lansing mixers and Altec Lansing amps in the late 50's. That type
of construction is also used on military electronic equipment. The turrets are
staked into the board and the components are mounted to the turrets. The layout
on the component board is meticulous, with short jumper wires connecting one
turret to another, completing the circuitry.
Layout is critical. Bad layout hurts tone and almost every classic amp design
has glaring mistakes in the layout - too much wire, too long of grid circuits,
bad choices in placement of components. The layout in the Gerald Weber Signature
Amp is a work of art. There is almost no wire in this amp! The layout was carefully
designed and redesigned so that all grid circuits are extremely short (this
makes the amp sound even better). Also, different brands of components are used
for particular circuits - depending on which brand or type sounds best in each
particular part of the circuit. Every component has been tweaked to the max.
All non-polarized capacitors are installed in proper polarity to prevent hum
(this is an important process that has been ignored by virtually all amp builders).
All grounds are in the correct places and a brass grounding buss is used.
The Gerald Weber Signature Amplifier ( hereafter called GWSA), has the best
sounding and most functional reverb that has ever been designed into an amp.
The reverb circuit design started many years ago when I designed a unique, transformer-driven,
three-knob reverb circuit to be used as an add-on to the fabled Kendrick 2410
amp. This circuit was refined over the years. Everyone loved this reverb circuit.
It was unique to Kendrick and voiced completely by ear. Later, another triode
section was added and it was refined further. The reverb circuit, unlike stand-alone
reverbs, is not in front of the preamp. It is "along side" the preamp
and is injected back into the circuit at the output stage. This allows for dreamy
and spatial reverb, independent of preamp distortion. The"reverb drive"
control simulates the room SIZE. The "reverb tone" control, completely
independent of the dry-signal tone, can change the reverb tone from Pacific
Ocean drench to Texas Barn Stomp mellow. And the "reverb mix" control
allows you to add any amount of reverb to the final mix.
There are two channels to the amp, yet three inputs. There is a clean channel
input, a lead channel input and an input that connects to both channels. The
"Both" input allows you to use the volume control of each channel
and blend a clean tone *on top of* a lead tone for that "Stevie sound"
- think multi-amp tone, but from a single amp! There is a treble, middle, bass
and presence control that is common to both channels.
Although it is generally agreed that the blackface tone of the mid sixties is
the definitive clean tone, that thought prevailed only because I had not designed
the GWSA before now. Unlike the thin (by comparison) clean sound of the 60's
blackface amps, the clean channel of the GWSA has breadth and fullness. It seems
to come from everywhere in the room at once. Although it has maximum width,
the mids are scooped just enough to keep the notes from competing for space
with each other. Every note is discernable and clear - like a long scale grand
piano. The notes sustain as if compressed, yet have the dynamics and punchiness
that compression otherwise loses. The volume does not have to be turned up for
this channel to sound full and rich - it sounds great at any volume. When the
channel volume is turned beyond 1/2 way up, the output tubes overdrive smoothly
and evenly but without any "out of tune" sub-harmonics characteristic
of Fender, Vox and Marshall.
The "out of tuneness" in classic tube amps is caused by inadequate
filtering in the power supply.When more current is used, you need more filtering.
Turn up your classic Fender (or Fender copy, reissue,etc.), Marshall or Vox
and notice the ugly "out of tune" sub-harmonics - especially when
playing a "B" or "B flat". Maybe I shouldn't have told you
about those "out of tune" sub-harmonics found in other classic amps.
Ignorance is bliss. If you haven't noticed them before, you most certainly will
now. The GWSA tone is pure and "in tune" at any volume - thanks to
a superior design in the power supply and highest quality American-made filter
capacitors.
Some classic amps are raspy when overdriven but not the GWSA. The lead channel
of the GWSA overdrives so smoothly that if it weren't for the percussiveness
of the attack, you wouldn't be sure if you were hearing a guitar or a very loud
cello. No kidding, it is such a musical tone, that you don't really need to
play a lot of notes. You will find yourself playing slower and enjoying each
note more. But if you are a speed demon, the amp is very fast - so fast that
it seems as if the amp knows which note you are going to play before you play
it. There will be times that you will be sure that the amp beat you to the punch.
Speaking of punch. Most classic amps are made from pine. Pine sounds very good.
If you listen to a pine cabinet by itself, you will be impressed. Compared to
Brazilian Canarywood, the pine loses. When you A/B compare pine and Canarywood,
the pine (that sounded very good by itself) seems garbled and out of focus.
The Canarywood sounds as if it is pin-point focused. Maybe this focus accounts
for the superior punchiness found in Canarywood. Even though the GWSA is open
back design, this type of extreme physical punchiness is uncommon and usually
only found in closed back designs.
Also, the Canarywood has uncommon clarity. Take a vintage amp design and play
a closely voiced interval (such as a C and B, 1/2 step apart - like in a C major
7th). Notice how the notes compete for space and blur each other. Do this same
test with the Canarywood and the notes will be clear, focused and discernable.
Each note will have its own space and not try to blur the other one out. Sure,
a closely voiced chord will be dissonant, but the clarity and space of the notes
are like the difference between a spinet upright piano (pine) and a long scale
Steinway Grand piano( Canarywood), tonally.
Kendrick custom-made transformers are not copies of any other transformers.
Beginning in 1994, we had our transformer specialist make transformers out of
every known type of core material. I had heard legends about how certain amps
sounded so good because they used a particular type of steel laminate in the
output transformers. Some people claimed M-26 steel was the best. Some collectors
swear by the Mo-tauk 50 found in early Marshall 100 watt amps. Still others
favor M-27, M-36 or M-22. And there are die-hards claiming the M-18 found in
early Fender amps was best. Also, there are different ways to design the windings
and interleaves. We did the research and we know what is best for guitar tone.
This stuff has all been sorted out. The output transformer on the GWSA is the
result of eight years of research and it sounds like it. Oddly enough, there
are only a few classic amps that used the same core material that is used in
our output transformer, and there are no other companies with transformers wound
like ours. Also, the power transformer in this 50 watt amp is larger than the
power transformer in most other 100 watt amps!
The Kendrick GWSA features two 12" FANE (British) speakers. These are probably
the most expensive guitar speakers on the market, but they are the best in my
opinion. These speakers have a huge AlNiCo magnet. (The Hiwatt amps of the 60's
used FANE AlNiCo speakers). If you are not familiar with FANE, they are the
oldest speaker manufacturer in the world. They also own speaker patent technology
that they invented, and no one else can use. One of these patents is the fiberglass
voice-coil former, which is found on their 12" AlNiCo speaker. The fiberglass
voice-coil former can take the heat without burning up and has tonal qualities
not found with other voice-coils. The speakers are loud and very efficient,
which translates into punchiness, with lots of response to picking dynamics.
When played clean, they have plenty of bottom-end clarity with a smooth midrange
and chimey top-end. When they are overdriven, the top-end compresses slightly
(which smoothes the highs), while keeping the punchiness and focus of the bottom-end.
These speakers are the ultimate for clean or overdriven guitar tone.
"The Gerald Weber Signature Amplifier", Here are the answers
for everyone's questions.
Tubes - The amp uses a GZ34 rectifier tube configured as an "Invincible
Rectifier", a pair of E34L output tubes (these are military spec EL34 tubes.
In Europe, the "34" is put between the "E" and the "L"
to designate military specification), five 12AX7's and a 12AT7 (reverb driver
tube).
Internal wiring - The image (below) shows the pots and how they are wired. Notice
how the components on the board are cleverly laid out so that the wire connecting
them to the controls is about 1 1/2 inches long. In fact, the connection is
directly beneath the potentiometer lead it gets connected to. All ground connections
are laid out exactly in the best place for them.
On
the component board picture (right), notice how the components are elevated
slightly off the board and short jumper wires connect the turrets to one another
to complete the circuit. Also, notice the placement of the three big blue filter
caps on the right end of the board. Filter caps are made from an aluminum can,
which is grounded. These three caps provide a barrier, or shielding, for the
first gain stage components of both channels. Also, by having them on the board,
I can run the grounds exactly where they need to be. (There are five more filter
caps in a cap pan on the other side of the chassis and their grounds are run
separately to where they need to be.)
On
the sockets picture (left), you will notice that the phase inverter has been
rethought. It is actually flipped over from the standard configuration that
is seen on all early Marshall and 60's Fenders. I never could figure out why
Fender and Marshall configured the phase inverter components which resulted
in extra long grid wires. Fender did it as a mistake and Marshall copied Fender!
Have you ever noticed how all Plexiglass Marshall amplifiers have a parasitic
oscillation if the volume, presence and treble are turned up? It is because
the output tube grid wires are too long. If you look at my board, THERE IS NO
GRID WIRE! That is right, the components are configured where the coupling caps
coming from the phase inverter end up 1/2" away from the grids of the output
tubes. This allows me to use the lead from the output tube's grid resistor to
make the connection back to the coupling cap.The plate load resistors are at
the top to make the plate wires from the phase inverter tube slightly longer,
but the grid wires non-existent.
Notice the three input jacks. One is "Clean", One is "Lead"
and the other is "Both". That is right; you can run both channels
simultaneously and blend the volumes to get "Lead" on top of "Clean".
Look at the wires going from the input jack to the board. These are special
double shielded wires. They have shielding over the shielding! Church mouse
quiet. You might also notice how the sockets and the components feeding them
line up, so there is almost no lead length, (except for the two yellow plate
wires coming from the inverter). The less grid wire in an amp, the better it
sounds.
What is an Invincible Rectifier? When High voltage AC comes from the B+ winding,
part of the cycle is negative. Imagine a negative voltage of about 350 volts
on a tube that is seeing 485 volts DC positive. From - 350 to +485 is a difference
of 835 volts as far as electrical potential. And we wonder why rectifier tubes
arc? In my design, I put diodes in series with the plates of the rectifier.
This does not alter the rectifier sound, BUT IT KEEPS AC SWING VOLTAGE OFF THE
PLATES! No more rectifier tube arcing! Also, in the event that the rectifier
tube ever did short, the amp would still work and not go down onstage, BECAUSE
THE DIODES WOULD TAKE OVER THE TASK OF RECTIFICATION! Also, there is a matrix
of resistors and diodes in parallel with the tube so that IF THE CURRENT HANDLING
CAPABILITY OF THE TUBE IS EXCEEDED, 25 % OF THE CURRENT IS BYPASSED AROUND THE
TUBE, THUS PREVENTING A TUBE MALFUNCTION.
Why an E34L? When I was testing EL34 style tubes to determine which tubes had
the best tone, I recorded them in my studio. I put a pair of tubes in the amp
and recorded a clean example, moderate overdrive example and a heavy overdrive
example. Then I rewound the tape deck, plugged the mike into the next channel,
changed tubes and biased the new tubes and then overdubbed the recording. This
process was repeated with all fourteen EL34 style tubes. So I ended up with
a different tube on each channel, but nothing else was different. I could then
mute all the tracks except one and listen to those examples. I could mute that
channel and unmute another channel and switch back and forth. This allowed me
to hear the difference quickly enough, before I forgot what the other one sounded
like.
I noticed that the Mullard EL34 and the Slovakian made E34L were
noticeably louder than all the other EL34 style tubes. In fact, both of those
would compress the highs when overdriven to make a creamy smooth overdrive.
But, as far as clean tone, the Mullard lost, but the Phillips 6CA7 (American
name for the EL34) and the Slovakian made E34L both had a 6L6-like roundness
and chimey clarity not found in the other EL34 tubes. The E34L was the clear
all around winner.
How hard is it to bias the amp? Most of us know the importance of biasing our
output tubes - especially when changing tubes. Nobody likes to dismantle an
amp to bias it and those bias probe thangeys require taking tubes out and replacing
them.
The GWSA has the Kendrick Quick bias on the bottom of the chassis. This allows
you to BIAS THE AMP WITHOUT TAKING ANYTHING APART OR REMOVING ANY TUBES. There
are three pin jacks - two red and one black. You need a digital meter (autoranging
Fluke Model 10 available at home Depot for about $50). The black meter lead
goes into the black pin jack and the red meter lead goes into either red pin
jack. (Each output tube has its own RED pin jack so you can see how much current
the tube is pulling, but for the purpose of setting initial bias, either will
work.) You turn the amp "On" and adjust the trim pot until you see
.035 volts on the meter. At this point, you move the red meter lead to the OTHER
red pin jack. This is to check the other tube (to make sure it is matched with
the first one.) This process takes about 1 minute and after you have done it
once, you can carry on a conversation, chew gum and do it and still get it right
every time. You will find yourself biasing the output tubes frequently, because
it is so easy to do and the amp will sound its best when properly biased. You
tune your guitar, why not tune your amp?
