a monophonic tonearm cable is not at hand, a conventional stereophonic tonearm cable
can be used equally well (with both plugs inserted into the respective jacks), in which
case shorting the inactive left input can be conveniently accomplished at the very end of
the left channel lead of the tonearm cable by shorting the "left hot" and "left ground" pin
of the headshell. If the tonearm is equipped with free leads, the desired conductive
connection can be easily formed by taping the lead ends of the respective tonearm leads
firmly together. After these adaptations required to create dedicated single coil cartridge
input, signal doubling can be obtained at the output by connecting both power amps to
the right channel main output by using the respective paralleled pair of jacks.
Note, a doubled version of the right channel rather than a proper stereophonic
signal will be reproduced by the system in dual-speaker-mono mode if a
stereophonic source is (accidentally) switched active.
ABSOLUTE PHASE OF LINE OUT SIGNAL
Line amplification in the “Super” is performed by a unique single stage, zero feedback
circuit employing one 12SN7GT tube per channel. This topology has several technical
and sonic advantages over a more common multistage circuitry, and yet the line amplifier
is still capable of driving long interconnect cables and/or power amplifiers having an
input impedance as low as 10,000 ohms without compromising sound quality. As a side
effect of this puristic concept, the output signal of the line amplifier is 180 degrees out of
phase relative to the input signal. Thus, for a correct absolute phase in the system, the
speakers should be connected to the resective power amplifiers with reversed red black
polarity. That is, connect the red binding post of the amplifier to the black binding post of
the speaker, and vice versa. Here we assume that all other components in the setup
process the signal without phase shift and phono cartridges are wired for correct polarity.
For correct overall phase in a setup with the THÖRESS Full Function Preamplifier,
the speakers should be connected to the power amplifiers with reversed
red-black-polarity.
Note, that in our Full Function Preamplifier the volume of each channel is controlled
separately via high grade rotary potentiometers (custom made to order by ALPS in
Japan) and these parts are carefully matched, to preserve precise channel balance with
respect to the rotation angle (and thus to the scale printed on the faceplate).
INPUT SENSITIVITY AND THE PREAMPLIFIER’S IDLE NOISE
The noise performance of the line section of our preamplifier is such that no audible idle
noise will be present in the setup as long as the power amplifier and the speakers are
suitably matched with respect to input sensitivity and speaker efficiency. We guarantee
that line amplifier idle noise will remain within inaudible limits when using speakers up
to 100dB/W/m efficiency with each of our power amplifier models. But line amplifier
idle noise will unavoidably become audible in cases where the power sensitivity of the
power amplifiers are high (solid state amps) and/or the speakers are exceptionally
