Although cartons are the usual sight even well beyond today's prices, Alberto used two 1560 Pelican cases selling for roughly €200 each. Not only were these watertight, crush/dust-proof boxes easy to carry around, their build quality is solid enough to withstand anything conceivable. Inside precisely cut foam cushioned one mono amp plus quality power cord, manual and a small cylindrical bamboo box for the patented GaNTube. Such rugged packaging and neat innards made for a quality first impression. A cool $15'000 buys you two mono amps of 10kg each measuring 28x28x13cm WxDxH for compact easily managed square casings. Each slightly rounded enclosure is milled from a sand-blasted block of billet aluminium and sports four footers with rubber protectors. Each case shows a nicely engraved logo on the front, the rear the RCA/XLR inputs, selector toggle, a pair of quality WBT terminals and an IEC inlet with 115/230V voltage card.

Specs list nominal and maximum output power of 100W into 8Ω at 0.01% THD+N (20Hz-20kHz) and 200W into 4Ω at 0.1% THD+N (1kHz). THD+N at 10W/1kHz is below 0.005%, bandwidth ±3dB 5Hz-100kHz, efficiency better than 94%. A-weighted output noise is equal to or less than 45μV, dynamic range 120dB. Switching PWM frequency up to 768kHz seals the deal. Clearly this is no ordinary class D. Where the vast majority of amps feature plain bonnets with perhaps vents for a visual motif, Vivace sports an intriguing truncated pyramidal dome of smoked acrylic. Its flat surfaces magnify and distort the internals slightly and discrete orange LED strips add illumination. The effect is fabulous which my photos attempt to convey. Even though this glow can't be defeated, it's barely visible thus unobtrusive from the listening position. It's also worth knowing that the extent of the glow in my photos was deliberately heightened for effect with strategic lighting and exposure.

Each acrylic top sports a generously wide opening with standard 8-pin valve socket beneath. This doesn't accommodate regular tubes but Alberto's very own GaNTube. Once sprung from their bamboo compartments, they resemble regular KT88. However, they contain no vacuum but a complete transistor output stage. A compact dual PCB features caps, LEDs, ICs and the key GaN beneath a black radiator. Perforated bases improve air circulation. Can you see an angry mob with torches and pitch forks at the ready? Can you hear accusations of sorcery, witchcraft and blasphemy? Can you smell the burning stake? I can't say whether Alberto did. If so, he undoubtedly had a good time in his fortress from the future. With his family name Guerra translating to 'war', he's certainly well prepared for any opposition.

There are several reasons why Alberto views a glass enclosure as perfect for his GaN circuit. As an Italian, he has a soft spot for visuals. That's why he pursued gently rounded Art Deco styling and a square footprint. The nicely lit acrylic top boosts the visual score and a tube right in the middle adds a turbo to the concept. But replaceable valves also add modularity. My loaners arrived with a set of KT88 GaNTubes but a more powerful KT150 is already finished and more types might bow in the future. Just as one can swap tubes in valve amps, Vivace unlocks the option to roll solid-state output stages. That's novel. In this context, the rationale for a glass shell becomes quite multi-layered.