AUDIO-GD MASTER 9 MK3 Balanced Headphone Amplifier / Preamplifier Pure Class A Silver

With the Master 9 MK3, Audio-GD presents the latest version of its headphone amplifier/preamplifier. This model builds on the success of its predecessor, still being a dual mono Class A headphone amplifier. With this new iteration, Audio-GD has mainly worked on the miniaturisation of its amplifier, going from a 16kg model to a 7kg model, without making any concessions to the quality of sound reproduction.

Audio-GD Master 9 MK3 : Gain control

The Master 9 MK3 incorporates a gain adjustment function, making it easy to adapt to any type of headphone, even the most difficult to drive.
- The "L" (Low) mode has a gain of 16dB, making it suitable for powering headphones with a sensitivity of even more than 100dB, or for use as a preamplifier.
- The 'H' (High) mode has a gain of 25dB, enabling headphones with a sensitivity of between 80 and 100dB to be powered.

Audio-GD Master 9 MK3 : A design without compromise

The output stage uses a diamond structure for its circuit. This particular structure uses 4 transistors in a configuration reminiscent of a diamond crystal if represented schematically, it has the dual advantage of being fast and accepting high loads. Four 150W transistors are used per channel, operating in pure Class A. As a reminder, Class A amplification has the particularity of having its active components always in conduction. As a result, they amplify the input signal in its entirety, greatly limiting the total rate of harmonic distortion at the output. And so, thanks to its diamond structure and Class A operation, the Master 9 MK3 has signal processing that's both fast and distortion-free, for a result of rare quality.

Audio-GD Master 9 MK3 : Innovative volume control

The 100% discrete design of this amplifier (no OPA) is supported by a volume control that differs from conventional methods. Traditionally, volume control takes place in the input stage of the amplifier via a potentiometer to reduce the signal. The main problem with this method is that the quality of the potentiometer has a direct impact on the quality of the sound, which can easily lead to a loss of detail, channel imbalance or distortion that will later be amplified. So even with a quality potentiometer, its impact on the signal-to-noise ratio can be felt. To address this problem, Audio-GD uses an I/V converter located in the output stage of the Master 9 MK3. The task of this converter is to transform the signal current into voltage, so volume control depends on the conversion rate applied. This solution has a twofold advantage: firstly, it operates at the output stage, so has no impact on signal processing; secondly, the integrity of the original signal is preserved, since control is via a converter and not a resistor.

AUDIO-GD Master 9 MK3 remote control

The Master 9 MK3's remote control not only controls the preamplifier/headphone amplifier, but also an external Audio-GD DAC, if you wish to pair one with the Master MK3.

1	Mute mode
2	Preamplifier Auto dim
3	Input source selection
4	Gain
5	Volume control
6	DAC controls