Tax included


Currently not available, in course of order.


WARRANTY2 years warrantyDedicated support


EASY RETURN 14 days satisfied or refunded

Headphone Amplifier / Dual Mono ACSS Balanced Preamplifier

The unique feedbackless ACSS preamplifier applies four feedback-free output channels consisting of 8 pieces of transistor, each piece has 15A / 150W performance. The capacity of the whole machine reaches 36,000 uF. Three R-core transformers are used with a total power of 145 W. The preamp output is built into the unique buffers. 4 PSU class A power supplies for left and right audio signal amplifiers. The volume control based on four-channel digitally controlled relay to 100 steps any kind of imbalance. The relay-based pre-volume control of the 9-phase four-channel digital controller can control the input level of the source from 0DB to -9DB. Two gain modes, high at 20dB and low at 10dB, for greater flexibility.

5 analog inputs: RCA X2, XLR X2, ACSS X1 (also with RCA or XLR inputs, ACSS output available)

3 preamp outputs: XLR / RCA / ACSS

4 headphone amplifier outputs: 6.3mm / 4pin XLR / 3pin XLR * 2

Unique ACSS Preamp / Preamplifier technology without feedback

HE-9 LE balanced applies the brand new ACSS design. It sounds complex, but it actually represents the simplest design the Hi-Fi world has ever had. The HE-9 LE integrated amplifier has a single "voltage" gain stage to process signals, but operates in ACSS mode, so in effect it is a current gain stage instead of voltage, while normal OPA chips do it already includes two or three stages. The simpler and shorter signal travel brings out the more neutral and less colorful sound.

HE-9 LE applies a very low distortion single-stage ACSS amplifier soldered directly to the motherboard. The gain stages and the diamond cross output stage A.

ACSS is a feedback-free technology built with fully discrete amplifiers. Most people can offer that feedback design can offer better in test analytics while non-feedback works in better ears, however it can offer for man ears. The ACSS offers a range, in that it can deliver a tone with a colouration, more neutral and with a new minimum very low distortion and high linearity. So it can keep dynamics, details and neutral sound without sounding bright or harsh.

All the signal gain is current, obtained from the unique and superb open loop multiple output current mirror. The result is an incomparably precise and ultra-low distortion of the gain signal. The signal path is fully balanced and all transistors in class A mode.

Volume control

The volume control is also different from conventional technology. The volume control technology provides a volume control in the analog amplifier input stage through a potentiometer to reduce the signal. This way the quality of the pots directly affects the sound quality, a low quality volume pot causes loss of detail and channel imbalance causes sound distortion. Even the high-performance volume pot still causes loss of detail.
But our project, we applied the I / V conversion volume control, the volume control has a variable passive I / V conversion position at the ACSS amplifier output, where the output is the current signal and not voltage .
Volume control with I / V conversion, can flat signal frequency band and not miss any detail. It cannot degrade on the sound quality in every volume level. After the loudness, there are four groups of non-feedback buffer stages that offer very low output impedance.
The quality of the volume control is very important in balanced design. The volume control must ensure the signal control of the four channels exactly to achieve the performance of the balanced design. If cold and hot the balanced signal cannot guarantee the exact balance, the balanced output will have great distortion, as the sound quality and performance are even worse than that of a single power stage.
A four-channel digitally controlled relay based volume control is applied in our project. This machine has four total channels and uses DALE resistors to control the volume to avoid unbalanced channels.
The volume control has 100 steps, the control range reaches 90DB, a very smooth control range on the first 50 steps, cooperate with a high gain of 20DB, so it can easily adjust the volume.


S/N Ratio


<0.0025 %   HE9MK2THDs.JPG
THD+N <0.0025% HE9MK2DNRs.JPG

Frequency Band (XLR input)

20Hz - 100KHz (<4DB )


Volume characteristic

100 steps Supper Exponential Volume Characteristic

M8Svol1s.JPG  M8Svol3s.JPG
Headphone amp Output Power
 (Balanced class A )

25 ohm: 15W
40 ohm: 10W
100 ohm: 4W
300 ohm: 1350mW

Headphone amp Output Power
 (Single-ended  class A )
25 ohm: 4W

40 ohm: 2500mW

100 ohm: 1000mW

300 ohm: 350mW


High gain :+20DB
Low gain : +10DB

Output Level (Max)

9.5V @ RCA
 19V @ XLR

Output Impedance

10 ohm @  Preamp XLR
2 ohm @ headamp balanced output

Input Impedance

94K ohm @ XLR
<5 ohm @ ACSS

Channels cross
< -130DB

Channels imbalance
< 0.01DB

Power Requirement

1 Version  100-120V  AC 50/60 Hz
2 Version  220-240V  AC 50/60 Hz

Power Consumption

54W Class A  @230V or 120V

Transformer Power

145W (3 unit transformers)

Package Weight

Approximately 18KG

W430 X L485 X H123 (MM, Fully aluminium )  


Power cord  X1


Specific References

You might also like

16 other products in the same category:


No customer reviews for the moment.

Write your review



Write your review