Sound Performance Lab 2383 Stereo Amplifier User Manual


 
GainStation 8
23
Inside the GainStation 8
The most time-consuming part of the development of the
GainStation 8 was searching for, selecting and matching compo-
nents, PCB‘s and IC‘s. One decisive factor in achieving impec-
cable 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 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 distor-
tion. 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
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‘s input differential amplifier utilizes an extre-
mely low-tolerance, thermal-coupled matched transistor pair in
a single casing. This prevents deviances between the transi-
stors to ensure minimal THD (total harmonic distortion) even
at various temperatures. The resistors in the initial differential
amplifier are connected to a secondary differential amplifier—
also based on a matched transistor pair—that handles current
conversion.
Technology