The Gyratec 23-S works as follows:
The unit is stereo, single set of controls - based on dual-
technology: Either tubes and transformers – or fully solid-state,
with servo-balanced in- and output. Bypass is full-relay, and the
G23-S has a “TRIM” function for easing comparison between direct
and processed material.
The inputs are floating transformer balanced, 10K Ohm "bridging"
type, or 24KOhm servo-balanced. The input and output connectors
are standard XLR jacks, pin 2 hot. Outputs are floating
transformer balanced with a source impedance of less than 500
Ohms, or servo-balanced at less than 50 Ohm source impedance.
The main feature of the unit is the "Linear Tilting" knob (1). At
centre position it acts bypassed, providing linear transfer
through the unit. Turning the knob clockwise will gradually boost
higher frequencies while attenuating lower frequencies - and the
opposite way when you turn it counter-clockwise. At the end of the
knob travel you have a maximum of 1dB/oct - which equals to ca.
+/-4dB at the outer ends of the audio spectrum.
On top of this, we have the simple Baxandall tone control with
three boost/cut controls (3), centre detented and neutral when
centered. The available boost/cut amount is +/-6.5dB on lows,
+/-2dB on mids, and +/-4dB on highs. The curves are VERY gentle, a
wide bell for the mids and wide shelves for the high/lows. The
desired frequency range of the Baxandall part is set by the
frequency controls (2), each with three selectable frequencies.
No, we won't tell you where the frequencies are - but we spent a
good deal of time on optimizing both frequencies and boost/cut
range for best performance in the "unobtrusive" category..
(4) is your Bypass switch – it select solid-state (“S”) or tube
technology (“IN”)- and when set to “OUT”, it takes the entire
electronic circuit out of your audio path, and shorts the input
XLR's directly to the output XLR's by means of a relay. You don't
want eq, you don't get any..
The "Trim" control (5) is a control for fine-tuning the gain of
your processed material, making it easier to perform a same-level
comparison for judging sonic performance.
Last, the Power switch (6) to turn off the unit when it's not in
use. Tubes lasts long, but not forever.
Technical:
This Tilting-Equalizer is based on two closely-matched ECC88
output stages in the feedback chain of a linear cutoff slope
filter, and the topology is pure class-A. Lundahl audio
transformers with internal electrostatic shielding are used for
both in- and output interfacing, giving a true floating input
impedance of about 10KOhm, and an output impedance of less than
1KOhm. Solid-state part behaves like such should.
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