1, It has two gain modes for user select to match with the different gain power amps.
2, It has double volume control can match well with the different output level sources.
3, The new design apply the same board of Left and Right channels that make the design exact same,that we can measure and match the boards for assemble in the one unit to ensure the consistency.
- A cable is available to connect HE-1 ACSS outputs to a KRELL CAST amplifier input. KRELL amplifiers have lower gain versus audio-gd HE series amplifiers when using the CAST connection, so customers can custom order the HE 1 to have higher ACSS output gain if expecting to connect to KRELL amplifiers.
The HE-1 MK2 (introduced in April 2022) is a fully balanced Class A preamplifier with a built in regenerative power supply. It makes perfect new power and then supplies it to the preamp. It uses all discrete analog stages without any OP amps or coupling caps in the signal path. It has a zero feedback ACSS analog current output stage. The preamp uses three R-core transformers (In total 260W ) and more than 100,000uf audio grade NOVER capacitors are used to ensure ample and smooth power delivery. it has separate class A Power supplies for both the power regenerator and well as the fully discrete preamp that follows it. The HE-1 MK2 uses a four-channel 100 step digitally controlled relay-based volume control to yield superb channel balance. This greatly improves stereo imaging and and improves overall sound quality. It features 5 analog inputs. There are 2 RCA, 2 XLR and a single ACSS input. You even have ACSS output available to your amp as well as an ACSS, RCA or XLR inputs. The preamp can drive 3 power amps simultaneously
- 1. XLR balanced
- 2. RCA single ended
- 3. XLR balanced
- 4. RCA single ended
- 5. ACSS balanced (mini xlr)
- Balanced (XLR)
- Balanced ACSS (4-Pin XLR)
- Single ended (RCA / Cinch)
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 preampIt 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.