Country of Origin


Andante & Vivace Plus

Reviewer: Srajan Ebaen
Financial interests: click here
Sources: Retina 5K 27" iMac (4GHz quad-core with Turbo boost, 32GB RAM, 3TB FusionDrive, OSX Yosemite. iTunes 14.4), PureMusic 3.02, Audirvana 3, Qobuz Hifi, Tidal Hifi, COS Engineering D1, Denafrips Terminator, Soundaware D300Ref as USB bridge/SD transport
Preamplifier: Vinnie Rossi L2 Signature with WE 300B/VT52 or Elrog ER50/300B; Nagra Classic, Wyred4Sound STP-SE Stage II, COS Engineering D1, Vinnie Rossi LIO (AVT module)
Power & integrated amplifiers: Pass Labs XA30.8; FirstWatt SIT1 monos, SIT3. F5, F6, F7; Goldmund/Job 225; Wyred4Sound mINT; Nord Acoustics NC500 monos; LinnenberG Audio Liszt monos, Bakoon AMP-13R, SAG AIO
Loudspeakers: Audio Physic Codex; Cube Audio Nenuphar; Kroma Audio Mimí; EnigmAcoustics M1; Albedo Audio Aptica; EnigmAcoustics Mythology 1; Boenicke Audio W5se; Zu Audio Druid V, VI & Submission; German Physiks HRS-120; Eversound Essence; Fram Midi 150 & 120; Acelec Audio Model One; Node Audio Hylixa [on review]; Rethm Aarka [on review]; sound|kaos Vox 3f [on loan] Cables: Complete loom of Allnic Audio ZL 3000; Zu Event; KingRex uArt double-header USB cables; Tombo Trøn S/PDIF; van den Hul AES/EBU; AudioQuest Diamond glass-fibre Toslink; Black Cat Cable redlevel Lupo; Ocellia OCC Silver
Power delivery: Vibex Granada/Alhambra on all source components, Vibex One 11R on amps/sub
Equipment rack: Artesania Audio Exoteryc double-wide 3-tier with optional glass shelves, Exoteryc Krion and glass amp stands
Sundry accessories: Acoustic System resonators
Room: 4 x 6m with high gabled beam ceiling opening into 4 x 8m kitchen and 5 x 8m living room, hence no wall behind the listening chairs
Review component retail: TBA

Multiply and populate the world. Man wrote the book, followed its mandate, then didn't know when to stop. AGD Productions just got started. Being about upscale hifi not sex, overpopulation won't ever be an issue. Unhealthy interest still could be. It simply won't have young men go blind, just deaf.

Following the good book, AGD's portfolio is about to multiply. After his Audion & Vivace class D monos whose gallium-nitride Mosfet output stages pack inside 8-pin KT88 glass bulbs, designer Alberto Guerra now adds the Andante PreDac and a higher-power mono called Plus.

The original KT88 GaNTube of Audion & Vivace.

The switch-mode power supply of the original 100-watt Vivace (200w/4Ω, 360w/2Ω) contains a hidden voltage bus. Once wired up to replace the lower voltage bus, Vivace can drive the bigger new KT150 output stages to become Vivace Plus. So Vivace owners can have their amps updated at the California factory. That rolls with Alberto Guerra's concept of fast-switching GaNTube output stages which are plug'n'play modular. Unlike tube rolling for different flavors, AGD's scheme at least at present is primarily about scaling up power.

Of course all pure power amps still need voltage-trimmable signal to do their job. The fully balanced Andante provides such signal from various sources. It's a 32-bit R2R DAC with streaming, four analog inputs and three outputs. Passive volume utilizes a 256-stepped resistor matrix. There's HD AptX Bluetooth and DLNA, Roon, Tidal and MQA. In the menu, input 1 can reconfigure to MC/MM phono. XMOS XU208 USB supports up to 768kHz PCM and 24'576MHz native DSD512 on Linux/Windows, 12'288MHz DSD256 via DoP. RJ45 connects directly to the network. One box does all conceivable modern sources, file and resolution types with remote control.

As the following graph suggests, Andante is a low-distortion high-resolution affair. Its ~140dB noise floor exhibits very low 2nd and 3rd-order harmonic distortion. Any higher-order products move -145dB down. This gives Alberto's proprietary class D circuits ideal operation conditions to show off their high resolution.

Next we see one Vivace from my review of it which covered all of its tech very comprehensively. Rewired at the factory to become Vivace Plus, it'd return looking identical except for sprouting the bigger GaNTube from the asymmetrical back-lit plexi hood and carrying a higher power rating. Alberto aimed for 150/300w into 8/4Ω but thought that up to 360 watts could be possible. He'd know after his first 4-layer dual circuit boards for the KT150 arrived.

Andante and Vivace Plus are expected to finalize production in time for Axpona 2020.

At RMAF 2019 with Sigma Acoustics speakers with 2 x 15" woofers per side and, on the lower shelf, Andante bracketed by Vivace then Audion.

For now, a quote from HifiPig on the above show system: "This was seriously high end, with the speakers costing around €184'000. The massive speakers weigh in at 340kg each and are 100dB sensitive. Extreme Audio are the Italian manufacturers of Sigma Acoustics speakers. A system like this, in all its hugeness, could have come across as 'too much' but in fact the opposite was true. We were listening to opera, not my usual taste, but it was utterly captivating. The sound was unforced and delicate in a way that was almost at odds with the look of the speakers. A very clever pairing of brands with a natural result."

Our AGD review samples could ship by April when this story will continue…