ACSS (Audio-gd Current
Signal System) is Audio-gd's system for transmitting audio signals in
the current domain. This concept, first seen in 1966, we have used for
many years, and since 2006, have evolved the technology to include all
audio signals in our systems from the digital source to the power
amplifier. Since 2005, ACSS comp5nts have become Audio-gd's most popular
The C-2 functions:
Volume knob: Control the volume
level of the headphone/pre amp.
button: Push in for high gain (+13DB), out for low gain
(+4DB). Only available while using RCA input. ACSS input is always set
at High gain regardless of the Gain button for the best sound level.
button: Push in for
preamp output, out for
knob: Select input signal
between 1(RCA) and 2(RCA) and 3(ACSS)
The C-2 applies ACSS (Current Audio Signal Transmission)
technology. The heart of our ACSS technology is in the ultra low
distortion BPM-7110 V2 module. The sound of C-2 is neutral and
faithful-like, very neutral and sounds exceptionally clear and
Soundstage is precise, three dimensional and huge, detailed and
lifelike midrange, and transparent treble with tight and extended bass.
C-2 has three pairs of inputs: one set of
ACSS current mode input, and two single-ended RCAs inputs. If the input
signals are coming from RCAs, they are internally converted into
current signals and then amplified. To use the C-2 as a preamplifier,
there is one set of RCA output for your power amp connection.
In order to minimize interference and
distortion of sound quality, the left and right channel circuitries are
completely separated. To achieve a perfect performance, C-2 also
applies the complex Class A parallel-stabilized voltage supply to get a
purer power supply so that a better sound quality is guaranteed.
C-2 uses an all aluminum alloy chassis to
prevent the eddy current of the transformer from interfering with the
About volume in ACSS circuits:
C-2 use ACSS technology, which is very different
from conventional technology.
In conventional technology the gain is fixed, like 3DB or 6DB.
ACSS circuits in fact have 0DB gain and are fully
non-feedback, so it is a completely different circuit.
technology the "gain" changes with volume, and while you turn off the
volume, the "gain" is -80DB (in conventional technology it can't work
lower than 0DB).
While you are listening in normal
volume, the "gain" may be around -50DB, or between -80 to +13DB.
The volume control is also
different from conventional technology. Conventional technology volume
control is placed at the input, and attenuates the signal.
But in ACSS, it is placed at the
ACSS modules output, where the output is the current signal, not the
voltage signal. The volume control is I/V conversion, and the volume
depends on the current (I) conversion to voltage (V). (Like D/A chips
output I/V conversion)
The sound quality benefits
from I/V conversion volume control. Mark Levinson also knows that
current volume control has great benefits, so in their Top End preamp
NO.32 volume control, they use many components to change the signal to
become current signal (I), then through the R-2R network to control the
volume, and then changed back to voltage signal (V) again. But C-2
is simply a more complete work in terms of the current signal, and
technically, it is superior to conventional technology.