AGD Vivace Mk II - GaNTube Monoblocks

Regular price
Regular price
Sale price


  • Impactful, organic sound from Class D via patented, industry leading GaN power technology.
  • The most advanced power stage in Hi-End Audio.
  • Gallium Nitride (GaN) MOSFET based power stage fully integrated in a KT88 Glass Tube (Octal Socket). Future upgradeable. 
  • GaN is ~10x faster that standard MOSFET.
  • 85W into 8ohms, doubling to 170W into 4ohms (>30A max current capability).
  • 40kOhm input impedance.
  • <-130db noise floor.
  • No oscillation during rise and fall time.
  • No undesired harmonic residuals or other artifacts are transferred to the output filter.
  • Extremely clean switching characteristic which are a unique feature of GaNTube power stages.


Hifi Knights - Victor Award

"The Vivace emerged as one of the finest amplifiers I’m aware of, and undoubtedly the very best class D case I’ve heard to date, hence the ‘Victor’ award"


The AGD Vivace Monoblock, is the most advanced Hi-End Power Amplifier in the market. First to use the unique GaNTube™ technology with Gallium Nitride Power-Stage integrated in a Vacuum Tube. The Gallium nitride components are the key to the reference level performance of the AGD Vivace Monoblocks.
To achieve the highest-performance in audio reproduction, switching topologies must achieve nearly ideal switching waveforms, completely oscillation-free, to minimize distortion but most importantly, to preserve the harmonic content present in the original input signal and avoid 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 GaNTubeTM power stage, simplifies 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.

With the seamless ability to drive any loudspeakers, 200W of power, 48,000µF of super audio grade capacitor reservoir, and the fastest slew-rate, the GaNTube™ Technology delivers the purest sonic experience.

Thanks to the Gallium-Nitride power stage intrinsic characteristics, the virtually stray-inductance free package, and a state of the art layout of the power module, the rise time and fall time of the Vivace’s GaNTubeTM power stage are fully symmetrical at ~15ns. The output waveform at the switching node of the Gallium-Nitride power stage (pre-LC filter) is completely oscillation free even with a slew rate of 3700V/µs!

This oscilloscope snap-shot of the output power stage half-bridge switching node, is a dramatic evidence of the tremendous difference in switching speed between the Gallium Nitride Power MOSFET and the state of the art Silicon Power MOSFET equivalent.

The combination of low noise design technique implemented and the best practice for the internal board layout, the RF quality BNC connectors for the analog signals, are the key contributors of the excellent noise floor of the Vivace Monoblocks and extremely low distortion.


Type Monoblocks
Class D
Technology GaNTube KT88 MKIII
Power Output - p.c. 8ohm 125W
Power Output - p.c. 4ohm 250W
Input Impedence 40k ohms
Dynamic Range >120dB
Inputs 1x XLR, 1x RCA
Number of Chassis 2
Dimensions 190 x 140 x 190mm
Weight 5kg per unit



  • 2x mono blocks
  • 2x power cables
  • white gloves
  • all packed in a single, hard flight case 
AGD Vivace Mk II - GaNTube Monoblocks
AGD Vivace Mk II - GaNTube Monoblocks
AGD Vivace Mk II - GaNTube Monoblocks
AGD Vivace Mk II - GaNTube Monoblocks
AGD Vivace Mk II - GaNTube Monoblocks
AGD Vivace Mk II - GaNTube Monoblocks

Get in touch

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.