Ampzilla was created by world famous designer, James
Bongiorno in 1974. At the time, James was the director of engineering
at SAE. Prior to that he had been the director of engineering
at Dynaco where he created the renowned Dynaco 400. While at SAE,
James conceived the concept of the full dual differential full
complementary amplifier topology which has since, for the last
27 years, become the defacto world standard road map for virtually
all high end power amplifiers made today. Ampzilla was originally
designed as a construction project for Popular Electronics Magazine.
However, the response was so overwhelming, after the rave reviews,
that James left SAE to found "The Great American Sound Co.
Inc." (GAS CO.). The rest was history.
The Ampzilla circuitry was a refinement of the original
circuit created at SAE and the subsequent Ampzilla II, for the
first time in history, introduced the world to servo-controlled
amplification. It is interesting to note that servo-control has
also become a defacto standard on virtually all modern power amplifiers.
Subsequently, James, always searching for new and better concepts,
sold his interest in GAS and founded Sumo Electric Co. Ltd. for
the purpose of introducing yet another completely new concept
in amplification. What emerged was the four-quadrant full complementary
differential balanced power amplifier, "The Power".
At the time, this was the largest power amplifier ever made at
450 Watts per channel into 8 ohms. In addition, James received
a patent on a very unique pure class A power amplifier wherein
the bias was controlled by a very clever mechanism which allowed
the circuit to REMAIN in pure class A all the way down to a short
Unfortunately, disaster struck and James was afflicted
with life threatening liver problems. James has fought this battle
for almost 20 years and finally is back to health. During this
long absence, James has had plenty of time to assess the current
state of amplification. Surprise, surprise!! Since his departure
in 1982, there has been no conceptual topological discoveries
whatsoever. NONE!! Hard to believe, but true. This is not
to say that there aren’t any fine amplifiers being made, as there
are quite a few. However, virtually every one of them uses the
same tried (or tired) and true circuits created by James way back
when, with a lot of variations on a theme.
One thing is for sure. The cost of today’s gear
has gone astronomical to say the least. It is just simply not
possible to make the kind of super quality 200 watt amplifier
today for the same price that existed 20 years ago that is,
with the commensurate attention to detail that audio consumers
expect today. However, some companies have definitely gone to
the moon with megabuck pricing that is positively insane and
an insult to consumers in general. James has always been known
for producing the finest gear at the most reasonable prices
so that the maximum number of people could afford to own them.
James still has that same commitment however, today, in order
to make a super quality 200 watt amplifier with NO limitations,
the retail price must be in the neighborhood of $3000.00 per
channel when producing a MONOBLOC.
Twenty-Seven years ago James wrote a brochure describing
the "Ultimate Amplifier" while at SAE. Of course, every
engineer believes that their current work is the ultimate machine.
However, it should be understood that this "Ultimate"
design could only be as of the moment. The truth is that there
never has been nor will there ever be an absolute "ultimate"
perfect amplifier. Hard as we try, we get closer and closer but
in reality, we’ll never approach perfection. Therein lies the
enigma. Who defines what is perfect? What are the rules, the conditions,
the standards, etc. The original Ampzilla set a standard, which
has been copied, in topological form, for almost the last 30 years.
Obviously something must have been right about it in the first
place. Subsequently, the Sumo balanced topology has also been
copied for the last 10 or 15 years. As we are now entering the
new millennium, it is time for another breakthrough in the original
tradition defined by the first Ampzilla.
The new Ampzilla 2000 is a radical departure in
amplifier topology. Not many designers can make a claim like this.
The only other designer capable of true innovation is Bob Carver
although his application of technology and marketing go in different
directions. Needless to say, James has created something truly
new and innovative. All that can be said is, "It’s about
time." To expound on this theme a little, the following words
will describe amplifier topological "styles" of which
the descriptions are ours alone and are not to be found in any
There are basically five classes of topologies that
can be used to make an amplifier. These are:
Forward gain topology has without a doubt been the
standard bearer of solid state circuits for the last 35 years.
It is virtually impossible to make a tube power amplifier with
this topology. However, the latest "foolhardy" rage
of single ended tube amplifiers does use this topology WHEN THERE
IS ONLY A SINGLE OUTPUT TUBE (OR PARALLEL TUBES) in the entire
amplifier. So much for that nonsense.
Reverse gain is the absolute defacto standard for
tube amplifier topologies although, some of the earliest solid
state amplifiers used this style before all of us engineers learned
how to use complementary devices properly.
Quasi-infinite gain topology is something totally
new that is being currently worked on however, it will be a while
before all of the philosophy of this style is cemented.
Likewise for common-mode gain topology which in
the future may become the defacto standard circuitry for the next
Finally we come to what we call Remodulation gain
topology. This topological family includes any and all types of
switching, PWM, FM, etc., circuitry. It is our belief that enough
damage has already been done to the signal. Why screw it up even
more by converting to another format and then have to convert
The new Ampzilla 2000 uses a completely new variation
of the Forward Gain topology to achieve unprecedented improvements
in linearity. As a matter of fact, the new circuit is so smooth,
that it can be actually listened to OPEN LOOP, WITH NO FEEDBACK.
Of course, we aren’t going to make it that way. The PROPER use
of feedback is necessary in order to tie down all of the operating
points so there will be no variations in performance from unit
to unit. The new Ampzilla 2000 uses 12 250-watt output devices
per monobloc. This is 3 times more devices than the original
Ampzilla. In addition, since it is a monobloc, there is a separate
2000VA transformer for each. In addition, the amount of heat
sink radiating area is 3 times greater than the original meaning
that there is NO fan. Also, the B+ and B- supply fuses are EXTERNAL.
Also, The entire circuit is totally balanced from input to output
although there is a totally and uniquely new un-balanced to
balanced converter for single ended inputs. Each monobloc has
100,000 ufd of power supply filtering with dual rectification
as pioneered in the original Sumo's.
The nominal specifications are as follows and are
Power output –300 watts into 8 ohms at less than
.05% of any kind of distortion known to man.
Frequency response-- +/- .1db at any power level
from 20Hz to 20kHz.
Rise time – less than 2usec at any power level
up to rated output
Hum & noise – Better than –110db below full
Gain – Balanced inputs – 42x (32.5db) with +/-
1 volt RMS input
Unbalanced 42x(32.5db) with 1 volt RMS input
Load capability – will drive any load conceived
Some other details are as follows. All of the metalwork
(except heat sinks) is of 14 Ga. steel. All transformers are our
own design and are made in house. The amplifier weighs approximately
40 lbs. All input and output jacks are gold plated and of the
highest quality. The line cord is 12 Ga. with "welded connectors"
instead of crimped. All internal connectors are gold plated.
Without question, this new Ampzilla 2000 2nd
Edition will be a new dimension in amplifier technology for
the next millennium and with-out a doubt, as in the past, will
be copied by others.