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Gyraf Audio Gyratec II
The all-tube Recording channel....
Preliminary user manual, 14. November 2002.
The Gyraf Audio Gyratec II is basically an all-tube recording
channel, combining a microphone/line preamp, an equaliser and an
optical compressor. Although solid state electronics are used - in
the power supply and sidechain - the audio signal is never touched by
anything but tubes, transformers and passives. Very different from
most "tubed" consumer-type studio gear, and very good for signal
integrity.
The signal flow in the G2 is kept simple; all functions are realised
with only four double triode tubes - the 5814 military type. This
tube can be substituted with standard ECC82 or 12AU7A types, so you
don’t have to worry about tube availability for the near future.
The input switch (1) selects between "Instrument" (DI for e.g. Bass
or Guitar) "Line", "Mic" and "Mic 48V". The input impedance is 1K Ohm
for the mic input, 10K Ohm for the Line input, and 1M Ohm for the
