Forward to the future? I recently reviewed FirstWatt's SIT4. That's a single-stage single-ended transistor amplifier with zero feedback which delivers 10wpc into 8Ω whilst drawing a constant 200 watts at idle, full power and anywhere in-between. Hello true class A. For as stunning as that amp sounds on appropriate speakers, it takes no spite to state that class D will be the future for its power conversion efficiency of wall watts in vs music watts out. It seems both inevitable and responsible. From a sonic perspective it seems appropriate to gauge this future against the finest sound of the past and present. To many that's thermally wasteful purist class A whose output devices conduct fully at all times to suffer no 'crossover' distortion from switching lag. Anyone who subscribes to this notion should find it imperative that class D develop beyond cost-efficient OEM modules which already offer superlative specs whilst to many serious listeners not yet measuring up to the best of the 'antiques' on sound. Mytek's founder Michal Jurewicz clearly shares this assessment. He believes that with his current flagship, that inevitable future is now. He also calls GaNFet fast-changing tech. I translate that to mean many future refinements 'round the bend. Alberto Guerra is already on at least the 3rd generation of his implementation to validate such thoughts. What's the sound of Mytek's take on our audiophile future in 2024?

The Empire's rack.

The 'vintage' contingent might predict sound that's squeegee clean but sterile; with detail up the kazoo but an empty meat locker. Others might think overdamped so a bit clipped of cadence; or bass to die for but treble to die from. Expectations tend to be all over the place. It all depends on our prior exposure. Like elsewhere, there are stinkers and stonkers. If all we met were putrid sorts, we're expected to hold our nose. I've met both. My favourites were AGD's Vivace monos and Merrill's Element 114; both GaNFet. Given Michal's AGD connection, my hopes were high. I've not heard the Orchard, Peachtree or Technics versions. To my eyes, the Empire wins on cosmetics in that upper echelon of class D especially in my favoured silver. Prior to laying on hands, I wasn't sure about the faux tube. The webpage though promised an included cover should we prefer a non-illuminated look. As Henry Ho proved ages ago with his H²O IcePower amps on massive linear power supplies, switching outputs and switching power supplies needn't share a bed. Class A can sleep with SMPS as Aavik and LinnenberG do with push/pull circuits; or class D with linear power like today's Empire. Incidentally, Michal prefers his toroid for its superior transient performance.

How about vintage guy bedding future girl to execute class A with GaNFets? From Nelson Pass two years ago: "If you review the spec sheets on most GaN transistors, you'll notice that the safe operating area curves aka SOA do not specify operation for more than a few milliseconds. There is no DC curve offered. I discovered this the hard way when I bought a stack of Transphorm GaN fets and blew them up at 20 volts and 1 amp, which of course is 20 watts. They make great switches for class D but at this time I would say class A is right out, as is class B and AB."

On tube or not tu be, "we learnt from the shows that about 70% of people like the faux tube whereas 30% view it as problematic either conceptually or because it is fragile. Going forward we'll add a free solid top while the amp will ship with the tube cover installed. If a client wants to swap the lid, they easily can." On silver or black I was offered a choice so predictably asked for the former. And whilst this amp can bridge, I don't own speakers which warrant the expense. I was happy to learn that I'd get a single amp for regular stereo mode. It'd save me from having to parade around Cap'n Obvious in his rusty shackles and let him explain that while doubling this expense will double its power, it won't double our joy; not even close.

The attendant math is basic. To sound/feel twice as loud takes ~10dB of extra gain whilst getting just 3dB louder already eats up twice the power. So proponents of doing the Mytek Mono March are down to promoting superior channel separation. They argue that whatever happens to one channel's power supply under heavy signal attack can't pull down the other because both are physically and electrically separated. Will such theoretical benefits amount to €10'000 worth of extra joy? Would routing the same cash drain elsewhere reap more? Now we're deep into the muck of relativity where each shopper is on their own and reviewers plead the Fifth. No matter where we sit though, doubled-up joy for twice the coin does seem terribly unlikely. It's something to address when we've sorted more dominant weaknesses elsewhere and still want to spend more. Now it's ideal that the Empire amp isn't frozen in mono but bridgeable from stereo. We get to start singly and remain so indefinitely; or multiple in the future when those return percentages seem like a reasonable pursuit.

At hifi shows of course, two of these half-width boxes simply look more impressive than just one. There we expect to see a perfectly posh pair. "Our imitation tube is designed to reinforce the illusion that the amp sounds like a tube amp. The original idea comes from Alberto Guerra who created a GaNTube™ which contains his output stage. When I worked on our design with another engineer during Covid lockdown, we looked at AGD's page and scratched our heads why, with a Class D GanFet topology, there was a repeated claim that their circuit sounds like 'tube'. We were building our own circuits and evaluating them listening every other day. One day I had a revelation. The circuit started to sound like a tube amp, specifically the velvety top and beautiful midrange. But the bass which is usually problematic in most tube amps here was tight and controlled like in a good transistor amp." One months after writing the above in response to having been solicited with a "we're in production ready to ship" email, I checked on status. "Yes, we ought to have sent your unit already but are producing a new hardware version which you should have and this got delayed. We hope to ship no later than two weeks from now and are about to get the new boards done." With small firms wearing too many hats, it's quite common that communication falls through the cracks. It's often the price to pay when one wants to report on non-mainstream brands. Been there, done that, got the memo. About behind the scenes, Michal added that "we're still reorganizing manufacturing in Poland after splitting from HEM 2 years ago and the logistics of this are still being improved. But in my opinion the new Mytek products are very good and worthy of attention. My sample in NYC just played for David Chesky who thought it great. It has some warmth of AGD's Vivace but probably is faster and more accurate."

… to be continued…