Design Philosophy

The new AGD “THE AUDION” MkIII is one of the most Compact Amplifier Design in Hi-End Audio.

“THE AUDION” Monoblock uses the unique GaNTube™ technology with Gallium Nitride MOSFET based Power-Stage, fully enclosed in a Glass Tube.

The Gallium Nitride Power MOSFETS are the unique technology design advantage of AGD Productions, and are the key to the reference level performance of all AGD amplifiers.

With the seamless ability to drive any load, “THE AUDION” can deliver an unmatched sonic experience that only SET designs have been able to provide so far.

Now with 200W of power capability, a further improved voltage slew rate, and with 30,000µF of super audio grade capacitor reservoir, “THE AUDION” MkIII is uniquely capable of sustaining the most resounding bass punches while delivering the finest harmonic content of any vocal and musical instruments ensemble.

Crafted in a minimalistic ultra-compact solid aluminum case, “THE AUDION” has one single-ended and one fully balanced XLR input, (40kOhm std. and 600ohm upon request), enabling a perfect match with any direct source units (DAC) or preamplifiers in the market.

AGD “THE AUDION” MkIII Monoblock amplifiers are built around the same output power stage used in the AGD Vivace.

To achieve the highest performance in audio reproduction, AGD “THE AUDION” mono-block employs the same fundamental technology pioneered by the AGD Vivace design.

As with the AGD Vivace, also in AGD “THE AUDION” MkIII design we were able to achieve nearly ideal switching waveforms, completely oscillation-free.

Thus, preserving the harmonic content present in the original input signal and avoiding the superimposition of any additional artifacts that alter the overall spectrum and the spatiality of the music reproduction.

The Gallium Nitride power MOSFETs used in the GaNTubeKT88MkIII power stage simplify this challenge through its ability to efficiently switch at much higher slew rates than any silicon-based power MOSFET, with almost perfect (book-like) behavior and oscillation-free switching.

Residual THD+N @ 0db output, 4ohm, 1kHz

XLR Input (40kohm input impedance)

FFT Spectrum @ -20db (100mV)

XLR Input

PWM Frequency waveform at V switching point.

Voltage rise time waveform.

Switching voltage at V point >6000V/µs

Voltage fall time waveform.

Switching voltage at V point  >6000V/µs

115 Years of AUDION Evolution 1906 ~2021

Lee de Forest’s triode tube (Audion) from 1906.

• Top metal electrode is the plate.
• Grid is the bent metal wire partly visible.

• The most advanced power stage in high-end audio.
• Gallium Nitride MOSFET-based power stage.
• Fully integrated in a Glass Tube (Octal Socket)
• Extended bandwidth (±0.5db 0-50KHz)
• 200W, 4ohm (>30A max current capability).
• 800KHz PWM (GaNTubeKT88 MKII)
• 40kOhm input impedance.
• <-140db noise floor.

Main Features & Characteristics:

1. Power Entry Module
2. Fuse Holder
3. Input Voltage Selector
4. ON-OFF Switch
5. SPEAKER OUTPUT POSITIVE TERMINAL
6. SPEAKER OUTPUT NEGATIVE TERMINAL
7. Analog Input Selector Switch
8. RCA Single-ended analog input
9. XLR Balanced analog input