Yesterday, SF Express sent me a big box-I was still thinking "I haven't bought anything recently" until I saw the impressive Audio-GD logo on the box. Aha... The Audio-GDHE-9 Headphone/Pre Amp that netizens commissioned me to measure has arrived!
Its huge size forced me to remove it from the test bench to take pictures, and the weight of the device left a deep impression on me... Considering the recent short-term, mid-term and long-term market conditions for non-ferrous metals, this may be An investment method?
Okay, stop talking nonsense and start measuring:
Are these measurements good? not good. Bad? Not bad. So why does L7 put almost all the howling wolves and howling wolves? Because...UNBAL:
Measuring such a product, mine is a bit sad. What makes me sadder is that I saw the description of this product:
HE-9 is a true balanced design applying the newest ACSS design which can improve the XLR connection to sound as good as the ACSS connection.
The HE-9 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.
HE-9 applies ultra-low distortion single stage ACSS amplifier , an OPA already had built in two stages amplifier. they are soldered directly on the motherboard.
The ACSS is a non-feedback technology made with discrete amplifiers. Most people know the global feedback design can offer better specs in test measurements, and non-feedback can't do well in test measurements but can offer better sound for the human's ears. Here is a conflict of the classic circuits.
But the ACSS opens a new field, it can offer a least coloration sound which is more neutral with very low distortion and high linearity. So it can retain the dynamics, detail and neutral sound but not sound bright or harsh.
How dare you!
About regenerative power supply:
On Audio-GD’s product introduction page, they said:
While audio is life , the Power supply is water , Pure water create the wonderful life ,clean power supply reproduce the beautiful sound .
The regenerative power supply like a proprietary electric generator built in the unit.
It can block most disturb from the power line , supply the ultra clean power supply for the audio amps , reproduce the most neutral and analog sound like audio signal for the system and the users.
In the regenerative power supply design, the AC power through the regenerative input transformer , conversion to DC power ,through the class A PSUs power supply for the regenerative wave generator and driver stages .
A balance regenerative regular wave generator produce the ultra low distortion 50Hz wave ,through the balance gain amps and the strong output stages , drive the regenerative transformers produce the clean and steady AC power supply feed to the separate class A PSUs power supply for the L and R channel preamps .
The class A parallel connection PSU has very high input impedance to avoid disturb through the PSU from affecting the signal parts and low output impedance with very fast speed and high linear, it is a very clean power supply.
What a pity. Measurement tells us a different story:
We can see that not only the 50HZ noise and its multiplier still exist, but also a series of 52.667HZ multipliers...obviously...this 52.6 frequency is the frequency after "regeneration"...
What’s more serious is that...the unbal output of this product has a dc offset of about 20-30mv...whether it is the headphone output or the preamplifier output is the same
Its huge size forced me to remove it from the test bench to take pictures, and the weight of the device left a deep impression on me... Considering the recent short-term, mid-term and long-term market conditions for non-ferrous metals, this may be An investment method?
Are these measurements good? not good. Bad? Not bad. So why does L7 put almost all the howling wolves and howling wolves? Because...UNBAL:
Measuring such a product, mine is a bit sad. What makes me sadder is that I saw the description of this product:
HE-9 is a true balanced design applying the newest ACSS design which can improve the XLR connection to sound as good as the ACSS connection.
The HE-9 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.

HE-9 applies ultra-low distortion single stage ACSS amplifier , an OPA already had built in two stages amplifier. they are soldered directly on the motherboard.
The ACSS is a non-feedback technology made with discrete amplifiers. Most people know the global feedback design can offer better specs in test measurements, and non-feedback can't do well in test measurements but can offer better sound for the human's ears. Here is a conflict of the classic circuits.
But the ACSS opens a new field, it can offer a least coloration sound which is more neutral with very low distortion and high linearity. So it can retain the dynamics, detail and neutral sound but not sound bright or harsh.

How dare you!
About regenerative power supply:
On Audio-GD’s product introduction page, they said:
While audio is life , the Power supply is water , Pure water create the wonderful life ,clean power supply reproduce the beautiful sound .
The regenerative power supply like a proprietary electric generator built in the unit.
It can block most disturb from the power line , supply the ultra clean power supply for the audio amps , reproduce the most neutral and analog sound like audio signal for the system and the users.
In the regenerative power supply design, the AC power through the regenerative input transformer , conversion to DC power ,through the class A PSUs power supply for the regenerative wave generator and driver stages .
A balance regenerative regular wave generator produce the ultra low distortion 50Hz wave ,through the balance gain amps and the strong output stages , drive the regenerative transformers produce the clean and steady AC power supply feed to the separate class A PSUs power supply for the L and R channel preamps .
The class A parallel connection PSU has very high input impedance to avoid disturb through the PSU from affecting the signal parts and low output impedance with very fast speed and high linear, it is a very clean power supply.
What a pity. Measurement tells us a different story:
We can see that not only the 50HZ noise and its multiplier still exist, but also a series of 52.667HZ multipliers...obviously...this 52.6 frequency is the frequency after "regeneration"...
What’s more serious is that...the unbal output of this product has a dc offset of about 20-30mv...whether it is the headphone output or the preamplifier output is the same