1. Introduction to Fuchs Audio Technology Amplifiers
What makes our products unique?
The recent proliferation of "Boutique” amplifiers, allowed guitarists to experience what audiophiles
have known for years: properly designed tube circuits can offer the finest musicality, detail, and sensitivity
to playing subtleties of any type of amplifier. Anyone who’s enjoyed the sweet, responsive character of a
well-built tube amplifier realizes that it is nigh impossible model or simulate the “organic” qualities of a
live tube amplifier.
We feel our designs go a few steps beyond those of other manufacturers!
In addition to refining our circuit designs and operating points with computer "Spice" modeling, we also
spend countless hours tuning our circuits through careful parts testing and selection and then refining
the internal layout of our products. Details like single-point star grounding of all internal circuits,
premium audiophile grade power and output transformers, high-speed switching diode power supplies,
regulated and buffered DC power supplies for both filaments and high voltage sources, are key elements
to producing an amp that has truly unique sonic advantages. All completed amps are compared to
reference samples on both test equipment by live players before they may be shipped.
Our attention to the power supply and grounding result in an amp with extremely high gain capability,
but with a super low noise floor. This reduction in noise and increases in overall circuit clarity makes the
selection of components an even more critical element to achieving good tone. While we use many
time-honored component brands and features like “Orange Drop” Capacitors and/or carbon/metal film
resistors, we also use Audiophile grade “Wonder Caps” and unique circuit refinements in many parts of
our amplifiers as well.
It's a well-known fact that chassis materials can change the tone of the circuits built into them. We use
an aircraft grade T-6 aluminum chassis, which is 1/6" thick, bent at its edges for strength, and when the
front and rear panels are attached, forms a strong yet lightweight chassis. Aluminum also provides an
excellent heat sink for excess tube, transformer, or regulator heat. Although we install fans in all models,
our amps would dissipate plenty of heat even without a fan. The front and rear panels are attached to the
chassis pan with pem-nuts, a 1/8 thick assembly formed at both the front and rear of the chassis for
rigidity.
A combination of modern and traditional wiring methods
Internal construction in all models is based around a central circuit board, which supports most of the
power supply and the amplifiers FX loop, driver and bias circuitry. The balance of the amp is hand wired,
with particular attention paid to the preamp section and low-level circuits. All tube sockets are chassis
mounted for strength and ease of replacement in the unlikely event a socket fails. This also keeps tube
heat away from the other internal components in the amps.
Our amplifier power supply starts with a high voltage supply, which is rectified using high-speed
switching diodes, combining the sonic attributes of a tube rectifier, with the efficiency of solid-state
diodes. These produce greater voltages, a more rigid supply that doesn't 'bend' under the stress of loud
playing, and they also produce zero heat. This DC supply is highly filtered, using over 200 ufd of power
supply filtering, contributing to an amplifier that has a strong voice yet remains loud & clear up to it's
limits.
Our output stage(s) feature separate bias for each power tube. Although we use premium “matched
set” tubes as standard equipment, by individually setting bias, we can obtain maximum power before
clipping, extending tube life with better tone. Our power amp driver circuit uses an AC balance trim
control, which adjusts the signal balance to the power stage, keeping it linear, producing a clean, strong
tone. When driven to clipping, overloading is ultra- smooth, compressing in a sweet way, not at all
aggressive or harsh.
Premium Transformers
