Technology - SPL GainStation 8 Mk2 Manual

Technology

Inside the GainStation 8 Mk2
The most time-consuming part of the development of the
GainStation 8 Mk2 was searching for, selecting and matching
components, PCB's and IC's. One decisive factor in achie-
ving impeccable audio quality is the refusal to accept any
weak spots in the chain—the insistence upon each link being
as good as the next. It makes no sense to use a world-class
op-amp with an improperly engineered power supply or lower-
quality passive components such as standard resistors and
condensers.
The GainStation 8 Mk2 is based on fully discrete op-amps that
operate in class A mode. Class A operation dictates that both
end transistors are constantly conducting current to prevent
distortion. In conventional class B amplifiers, each transistor
carries a half-wave, and distortion occurs every time current
moves from one transistor to the next. Class A operation
requires much higher closed-circuit current—approximately
6 mA with this op-amps or roughly three times the total current
consumption of a conventional amplifier—which in turn leads
to increased heat generation.
Several months went into the development of the
GainStation 8 Mk2 op-amp. First, we tested several different
circuit configurations, using test equipment as well as listening
tests with a wide variety of program material. It became more
and more apparent that less complicated circuits provided
better audio results.
The GainStation 8 Mk2's input differential amplifier utilizes
an extremely low-tolerance, thermal-coupled matched transi-
stor pair in a single casing. This prevents deviances between
the transistors to ensure minimal THD (total harmonic distor-
tion) even at various temperatures. The resistors in the initial
differential amplifier are connected to a secondary differen-
tial amplifier—also based on a matched transistor pair—that
handles current conversion.
GainStation 8 Mk2
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