The cart is empty
auido-gd-he-9-preamplifier_345438398audio-gd-he-9_2audio-gd-he-9_3audio-gd-he-9_4Audio-GD - HE9 2019 - Regernative PSU Balanced Pre / Headphone Amplifier (RCA, XLR, ACSS)

Audio-GD - HE9 2019 - Regernative PSU Balanced Pre / Headphone Amplifier (RCA, XLR, ACSS)

€ 2.449
€ 2.024 excl VAT
Audio-GD HE6 Edition (High gain)
Additional RCA output (Replacing ACSS)
Power cable (Default C13 EURO)
In stock
Add to cart
  • Description
  • Specifications

Audio-GD - HE 9 (Regenerative Balanced Discrete Headphone & Preamplifier)

HE-9 is a Master-9 with an integrated regenerative power supply. A true balanced design applying the newest ACSS design which can improve the XLR connection to sound as good as the ACSS connection. They seem complex , but in fact they are the most simple design the world has ever had , their a lot components to process the power supply. The simplest and shortest signal journey brings out the most neutral and least colored sound.

HEr-9 applies ultra-low distortion single stage ACSS amplifier and soldered directly on the motherboard. It is a fully class A preamp / headphone amp and applies class A power supplies.


The 2019 Edition has been upgraded and has two different volume control characteristics. It can perform high and low gain modes without change the amp's parameter, hence without impacting the sound quality. And additionally a super gain control was implemented.
The Low gain mode has 16DB gain, for drive the headphones which have over 100DB sensitivity or work as preamp.
The H gain mode has 25DB gain, for drive the headphones which have 80-100DB sensitivity.
The S gain mode has 31DB gain, for drive the headphones which have 80-100DB sensitivity but with the low output level sources (Available on RCA/ XLR inputs ).

Sound Characteristics:  Extremely neutral

Note:  HE-9 can work with all sources and power amps worldwide, but its ACSS output is compatible with Audio-GD Master series power amps.


audiogd r7he mhreg psu

An integrated regenerative power supply is a proprietary electric generator built into the unit to avoid any noise from main power and deliver ultra-low noise and clean AC wave to feed the preamp

It will regenerate the main power and block noise from the power line, this way the preamp is able to reproduce the most neutral and analog sound you can imagine.

First a transformer converts main voltage. DC conversion is done by class A PSUs power supplies. 

A discrete balanced regenerative wave generator produces the new ultra-low noise wave form at 400Hz. The 400Hz frequency was chosen because they have better efficiency compared to traditional 50Hz and at this frequency, 400Hz, it will boost the sound to reproduce real and pleasant analog sound.

The balanced gain amps with powerful output stages are driving the regenerative transformers to produce the extreme clean AC power. The extreme regenerated clean AC power is send to separate class A PSUs power supplies for both left and right channel.

The discrete class-A DC power supply with high input impedance will avoid any noise and allow the amplifier stages to have low output impedance at very high speed and linear at frequency spectrum.


  • HE-9 has ultra high fidelity; its SQ is completely neutral. It can show how good or how bad a recording or source is.


  • A cable is available to connect Master-9 ACSS outputs to a KRELL CAST amplifier input. KRELL amplifiers have lower gain versus audio-gd Master series amplifiers when using the CAST connection, so customers can custom order the Master 1 to have higher ACSS output gain if expecting to connect to KRELL amplifiers.


  • Built in top class regenerative discrete power supply
  • Fully balanced pure class A design built by discrete analog stages without any OPA or coupling caps in the signal channels.
  • Non- feedback ACSS analog output stage.
  • Total applied 12 pcs exact matching 150W transistors ( In total 1800W )  as the output stages and PSU stages for implement large class A output power .
  • Uses three R-core transformers (In total 135W ) separate power supplies for the digital  control components, right and left channels.
  • More than 55,000uf audio grade NOVER capacitors are used to ensure ample and smooth power delivery. 
  • A total of 9 groups of  PSU's for dedicated DC supply. 
  • Uses most Hi-end grade parts and exactly matched transistors, OCC wires.
  • Four-channel 100 steps digitally controlled relay-based volume control avoids channel imbalance and improves sound quality .
  • Supper Exponential Volume Characteristic,  easy match the volume with very high headphone / speaker without change the gain mode.
  • 20dB gain can drive the low sensitivity headphone very well.
  • Static storage mode control software for avoid disturb sound quality , the MCU output once control data and save in the perform parts ,then stop output data until users next operation.  


  • 1. XLR balanced
  • 2. RCA single ended
  • 3. XLR balanced
  • 4. RCA single ended
  • 5. ACSS balanced


  • Preamp / DAC output :   XLR / RCA / ACSS (variable)
  • Headphone output : 4 pins XLR / 6.3MM SE 


Volume control consist of relay-controlled attenuators. Fully-independent, fully-balanced stereo volume controls. The volume controls feature consist of high-precision 0.05% tolerance film resistors and golden contact relays. Buffered inputs and outputs.There 4 channels volume boards are built in the unit to achieve ultimate balanced volume control. They are controlled by a digital signal controlling the high quality relays switching the precision resistors in analog area.

Audio-GD lineair volume characteristic Volume steps in comparison to standard volume control
volumecontrol1 volumecontrol2

Quality of volume control is very important in balanced applications . It have to effectuate the four channels to work as synchronous as possible to keep the balanced signal in perfect shape. In traditional volume controls the balanced output will introduce distortion which will negatively influence sound quality and performance and might even get worse than a single ended setup and waste the advantages of balanced designed solution.

S/N Ratio 
>130dB  (XLR output)

Low Gain : +14dB  (XLR)
High Gain :+20dB  (XLR)
Channel cross-talk
Channel imbalance
< 0.05DB
Frequency response

20Hz - 20KHz ( +/- 0dB )
10Hz - 100KHz ( +0dB,-0.7dB )
1Hz - 320K (+0dB, -3dB)
Output level

10V @ RCA
20V @ XLR
4.8MA @ ACSS
Headphone balanced power

40 ohm:   2500MW
100 ohm: 1050MW
300 ohm: 350MW
600 ohm:   175MW
Headphone Single ended power

40 ohm:   2500MW
100 ohm: 1050MW
300 ohm: 350MW
600 ohm:   175MW
Output impedance
< 1 Ohm on all outputs
Analog Input Sensitivity
RCA: 0.7V to 5V RMS
Analog Input Sensitivity
XLR: 0.7V to 10V RMS
Low gain mode : 0 dB, High gain mode : +12dB
Main Power
Version 2:  220-240V  AC 50/60 Hz
Power Consumption
Approximately 19KG
W430 X L450 X H125 (MM, Fully aluminium ) 
Accessories Included

1x AC power cord


Brand URL :
Weight: 20 kg
Width: 460 mm
Length: 430 mm
Height: 125 mm
Magna Hifi - Webshop: Audio-GDAudio-GD
audiophilles mh service



mh contact mh payable