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
C-39MK3 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-39MK3 is neutral and faithful like,
very neutral and sounds exceptionally clear and transparent. Soundstage
is precise, three dimensional and huge, detailed and lifelike midrange,
and transparent treble with tight and extended bass.
C-39MK3 has five pairs of inputs: one pair of
ACSS current mode input, two pairs of balanced inputs on XLRs and two
single-ended inputs on RCAs. If the input signals are coming from XLRs
and RCAs, they are internally converted into current signals and then
amplified. To use the C-39MK3 as a preamplifier, there are 3 pairs of
outputs, one XLR and one RCA and one ACSS for your power amp
In order to minimize interference, the left and
right channel circuitries are completely separated from the digital LED
display and controller modules to minimize distortion of sound quality.
Three special transformers are used to supply power separately for the
audio and control circuit. The signal amplifying section and the
voltage and control section are separately installed in different
chassis which further enhances the transparency of the tone to its
peak. To achieve a perfect performance, C-39MK3 also applies the
complex Class A parallel-stabilized voltage supply to get a purer power
supply so that a better sound quality is guaranteed. We are the first
people in the world to apply and make use of the ACSS power supply.
C-39MK3 uses a heavyweight all aluminum alloy
chassis to prevent the eddy current of the transformer from interfering
with the circuit board. C-39MK3 weight is 15KG. Furthermore, the
interior is separated into 2 sections by aluminum boards for the best
All the sockets of C-39MK3 use Hi-End
grade products. Everything that we have done has been for better audio
and sensational effect.
The control function of C-39MK3 is very
user friendly. The volume switch adopts IV method, which effectively
decreases the effect on tone quality. The overall impedance is
invariable, and the change of volume also applies in other ways. To
lower the control circuit's interference on the audio circuit, we
have applied a high-speed optocoupler to separate control signals and
executing sessions; in the same way that other sky-high priced imported
equipment adopts to improve quality. When not operational, the control
circuit is stopped and the control signal is temporarily stored in the
memory, which also outputs direct current levels to control the
executing session. This will effectively eliminate the detrimental
effect caused by long-duration data output of an ordinary control
C-39MK3 has a memory function. It can
independently memorize the status of the 5 input channel groups; and
maintain them even when the machine is shut down. Unlike machines
without a memory function, the input channel and volume do not need to
be adjusted every time the machine is operated. This function brings a
more convenient and pleasant way for users to enjoy music.
About volume in ACSS circuits:
C-39MK3 uses ACSS technology, which is very
different from conventional technology.
In conventional technology the gain is fixed, like 3DB or 6DB.
But in ACSS
technology the gain changes with volume, and while you close the
volume, the gain is -80DB or -100DB (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 +12DB.
The volume control is also
different from conventional technology. Conventional technology volume
control is placed in 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 the voltage (V). (Like D/A
chips output I/V conversion)
As you can see, ACSS circuits have no
gain, as it is a completely different circuit.
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 change back to voltage signal (V) again. But
C-39MK3 is simply a more complete work in terms of the current signal,
and technically, it is superior to conventional technology.
ACSS is fully non-feedback with very low
distortion, so sound is neutral (neutral and faithful) because it has
no feedback effect.
comes with remote control, the volume control uses resistors
components, which can avoid channel imbalance and improve on sound
quality compared to normal potentiometer.