Audio-GD – HE7 mk2 – 8xPCM1704U-K Regenerative PSU Balanced R2R Ladder FPGA DAC – PCM / DxD

FULL UPGRADE VERSION – ACCUSILICON

HE7 PCM1704U-K mk2 HIGHLIGHTS

• • 8x PCM1704U-K Chip!
  • Sample Rate indication for PCM and DSD on display
  • USB fully integrated and Isolated with internal FPGA deriving clocks from Accusilicon’s (similar to DI20 architecture)
  • Isolated HDMI input
  • Dual 32 bit parallel signal processing (FPGA) on I2S / USB inputs
  • Dual 24 bit parallel signal processing (FPGA) on SPDIF inputs
  • 10 MHz Master Reference clock input.
  • The FPGA process data upgrade to parallel mode.
  • Full new configuration clock manage design built in, improved on the clock timing.
  • Micro USB Port for firmware upgrades
  • Menu Mode controlled. All settings can be accessed via a menu on front.

SOUND CHARACTERISTICS

Characterized by its coherent, transparent and natural sound. Striking is the spatial sound image. Rich in detail; extremely high resolution; strong authority and wide stereo image. You’ll forget that you’re listening to a digital source.

Menu Controlled System

All functions operable from front panel for user friendly experience. In total 7 different sound characteristics: 4 different algorithms in NOS mode and 3 types oversampling modes. (Jumper-less version!)

SPECIFICATIONS

This model includes a Micro USB port on back panel. (Update without opening the unit)

BEST ANALOGUE OUTPUT STAGES

The analog output stages are as important, they have a tremendous influence on the final sound quality. After d/a conversion by the R2R D/A modules the analogue signal is transported by fully discrete matched-transistor output stages; DC-coupled design with first class through-hole components. No SMD compon ents are applied in the analogue section.  The high speed unique ACSS ((Audio-gd Current Signal System) output stages are non-feedback and current driven. Unique performance because almost all other designs need to convert the signal multiple times from and to current and/or voltage, resulting in less detailed and less transparent sound-stage The output buffers are single ended FET; two stages in parallel to reach very low output impedance. All output stages are in pure class A without (negative) feedback to achieve purest and a real live sound reproduction. The 4 OPA op-amp’s are DC servos, this way no coupling-capacitors are needed and DC output is automatically biased. The listener will be presented a strikingly transparent and neutral sound.

ACSS – Current Amplification

Audio-GD has developed an advanced current-driven amplifier technique. Also known as ACSS, Audio-GD Current System Signal. This special technique ensures that the signal travels a much shorter path and that ensures a more transparent, faster and more neutral reproduction. A similar technique is used by, for example, KRELL. The Current Conveyor technology mostly components are the current mirror. The Current Conveyor technology isn’t a new technology, at 1966 , professor K.C. Smith and A.S.Sedra publish the concept “current mode analogue circuits “ .

CLEAN POWER

The DAC consist of 3 tuned low noise, low flux leakage, R-cores transformers. In total 130W power to supply all digital parts and the left and right analog boards. The DC power is distributed over 19 separate power regulators. All are pure class A low noise shunts; fed by 3 groups linear power supplies. Resulting in ultra-high speed and clean power for all individual parts.