It was ‘Birdland’ that did it. I’d been listening to the Sugden Masterclass ANV-50 for a day or two. Not careful, reviewer type listening, you understand, just getting to know you listening, and it had been immediately obvious that Sugden had something a bit special on their hands, but it wasn’t until I happened upon that old Weather Report warhorse that I actually realised just how special.
Sugden decided to celebrate the 50th-anniversary of the A21, the world’s first production Class A transistor amplifier, by developing another pioneering design, but this time one with a distinctly 21st-century vibe. Two years on, the ANV-50 is that 50th-Anniversary product. It was designed with a few objectives: first, it needed to have a more robust power output than the 25-35 Watts of the A21; second, it needed to deal with the sometimes-unwelcome heat output of Class A designs; and finally, befitting the current era, its power consumption needed to be rather eco-friendlier. The 50‑Watt, cool-running, ANV-50 consumes 20 Watts when idling, compared to the A21’s constant 200 Watts.
So, job done then. Provided it doesn’t sound like all the musicians are texting their accountants while performing, obviously.
It doesn’t. The interesting thing for me, on first impressions, was how unlike the warm and easy Sugden sound the Masterclass ANV-50’s character seemed to be, but at the same time, how it retained that fundamental musical nous that Sugden products bring to bear. Sugden amplifiers, and particularly the A21, seem to manage an effortless facility with the important aspects that simply draws you in to the music. The ANV-50 does have that signature sweetness, though, and a kind of empathy with the music that can find beauty and meaning in all but the most raucous racket. So, actually, exactly like the Sugden house sound. But different, somehow.
The technology is different, too. Sugden, after a half-century of the ground-breaking A21 recognised that they needed another ground-breaking product to do it justice. So here it is, and it’s not Class A and, deep breath, it has a switched-mode power supply rather than a linear PSU. So, not just a development of the A21, which continues in production. But it’s not just any SMPS, you understand; it’s about twice as fast as conventional switched mode supplies, the better to replicate the speed and transient attack of Class A designs whose power delivery is instant, thanks to the ‘always on’ nature of the design. But Class A is a wasteful way to amplify a signal. Switched mode power supplies have come a long way since the likes of Linn and Chord first made them mainstream, and if you think you don’t like what they do, then perhaps it’s time to let the ANV-50 recalibrate your expectations like they did mine. The power amp section is itself a two-stage design, a small Class A stage drives a second Class A/B final output stage (the first 4 Watts or so are Class A) and the speed of the SMPS means pretty much instantaneous power delivery, all the time.
It’s an implementation Sugden think is unique. Trailblazing again.
DC-coupling keeps capacitors out of the signal path, and a new design of comparator circuit improves compensation for load (output doubles into a 4Ω load), making this a most flexible and fuss-free partner in a much wider variety of systems. It’s a very 21st-century solution, because it consumes so little energy except when it needs to. It’s also going to disappoint anybody who appraises amplifiers by weight: the Masterclass ANV-50 weighs barely more than half as much as the A21SE, largely due to the lack of need for a toroidal transformer, banks of capacitors, and hefty heatsinking. But don’t make the mistake of equating weight with quality. The usual unimpeachable Sugden build-quality, fit, and finish are there just as you’d expect. The switches and knobs are tactile and a pleasure to use. Take the top off and you don’t see machine-built surface-mount boards, just neatly laid out and constructed componentry in the time-honoured fashion.