Audio-GD - Master 1 (Balanced Discrete Preamplifier)
True balanced discrete preamplfier. Non- feedback ACSS Diamond output stages.All parts and components are selected based on excellent sonic and technical measurement performance. Components are e.g. from DALE resistors (USA), WIMA capacitors (Germany) and NOVER parts (UK). The used components but also the technical design (e.g. discrete analogue section and high speed FPGA's) of this system were being selected after many years of experience and practices and are considered to perform and provide supreme sonic results.
Master-1 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.
- Single polarity FET buffer stages in input and output, which is had a bit lower distortion and improve on the sound quality. The Single polarity FET stages have non feedback design (Toshiba K170)
- Power supplies imporvements; lower noise floor resuluting in a darker background.
- Users can enable/disable the "shorten" input signal now.
- Master-1 has extremely high fidelity; transparent and neutral sound.
- A cable is available to connect Master-1 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.
- Fully balanced design built by discrete analog stages without any OPA or coupling caps in the signal channels.
- Non- feedback ACSS analog output stage .
- Uses three R-core transformers (135W total), separate power supplies for the digital components, right and left channels.
- More than 50,000uf audio grade NOVER capacitors are used to ensure ample and smooth power supply.
- A total of 9 groups class A PSU's are used to purify the power supply. To achieve a high S/N ratio, the control circuit is powered with separate regulators.
- Uses high-grade parts and exactly matched transistors.
- Four channel 99 steps digitally controlled relay-based volume control avoids channel imbalance and improves sound quality.
- 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.
|Audio-GD lineair volume characteristic
||Volume steps in comparison to standard volume control
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.