Fuchs Audio Technology ODS-30 Operation Manual page 5

Premium Transformers
Our power transformers are designed for highest self-regulation as well as
conservative operation, assuring lowest heat and highest reliability. Our output
transformers (depending on the model) are premium grade audiophile quality. We
use custom built power and output transformers, as well as custom wound chokes by
Mercury Magnetics. All amplifiers feature 4 and 8 ohm outputs, grain oriented steel
cores, with heavy-duty mounting bells and hardware for maximum roadworthiness.
Buffered FX Loop
Our buffered FX loop features both series and parallel operation. It uses a
conventional high-current biased cathode follower, which provides a low-impedance
signal source, which is level adjustable and can drive from a pedal level to a rack
mount unit cleanly. Two simple switches set series/parallel operation, signal levels
from 0db to –20db, easily matching any and all effects, tube or solid state.
Studio Grade Reverb
Our reverb sections feature a solid-state current driven design. By treating the
reverb transducer as a current driven device (rather than a voltage driven device like
most other designers do), we have produced a quiet, dynamic reverb that sounds as
warm and detailed as a tube unit, plus the reliability of solid-state circuitry. This
saves on both space, and heat generation within the amp. Our reverb is interfaced
through the FX loop, adding warmth to the overall sound. Additional signal clarity is
achieved by eliminating the common reverb mixer network used by most other
manufacturers.
Our Preamp Circuits
Our preamp circuits form the heart-and-soul of our amplifier tone. Any subtleties
lost or masked by preamp stages are truly lost forever. By operating our low-level
circuits on a regulated and passively buffered high voltage supply, using a regulated
DC supply, we completely eliminate the effects of conventional power supply filtering
and decoupling. Audio signals can (and do) appear on power supply sources. Despite
large filter capacitors these audio signals do not belong on the pure DC that a tube
circuit needs to perform properly. This subtle coupling of signals from adjacent
stages can produce a masking of inner detail and potential instability in other high
gain circuits. A careful selection of passive parts (resistors and capacitors), as well as
the active parts (tubes and/or solid state parts), results in the unique sonic signature
our amps are becoming known for. We also use regulated DC filament power
supplies, for lowest practical noise floor.
Internal Construction
We proudly can say our products are built better than ever. Our circuit boards are
now two-sided extra thick boards, with heavy copper plating and a full solder mask.
Our internal layout has been refined to minimize wire runs, lowering the noise floor
to the circuit's practical limits. We still chassis mount our tube sockets for maximum
strength, durability and serviceability. We hand select our tubes for lowest noise and
optimal tone. All passive parts are carefully chosen for both reliability and sonic
attributes. Each and every Fuchs amplifier undergoes 20-40 hours of "burn-in"
before leaving our shop. This ensures every Fuchs amp is built for the long haul.
®© 2000-2005 Fuchs Audio Technology. All rights reserved.
ODSm 3/2005