Audio-GD – HE 9 2019 EDITION
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 ).
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.
- 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
HIGH PRECISION VOLUME CONTROL
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.
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.
REGENERATIVE POWER SUPPLY
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