Zinamp SCA Power Amplifier
My first forays into the world of current dumping were rather underwhelming. Having ‘upgraded’ from a Quad 303 to a 405 the clarity and openness of the 303 seemed to have deserted my much-loved ESL57s. Things weren’t much better with the KEF Calindas which were my second speakers at the time. Shortly after, the news that several studios (including the BBC) were using the 405 as a monitor amplifier led me to conclude that it was my ears which were at fault, rather than the 405. The second iteration of the 405 certainly seemed to inherit the reliability of the Mk1, but also seemed to be heading back towards the openness of the 303 which I still sorely missed.
Now, a few decades further on from those humble beginnings and current dumping as a topology has been refined and improved, with many of the early criticisms consigned to history, and several upgrade kits available for both Quad 405 versions. Other Quad products followed (including the 306 which I really rather like), and other manufacturers adopted current dumping as well – so it can’t have been all bad. Zinamp have also decided to follow the current dumping path, and their SCA Power Amplifier is really something of a peach.
With almost 70s styling, substantial side-mounted heatsinks (which never got more than barely warm) and both XLR and RCA phono inputs alongside volume control, this is a heavyweight but simple piece of kit. The Zin SCA Power Amplifier can be used as an integrated amplifier, but I also had a play with their rather natty Zinamp Valve preamp on the front end – but more of that in a future review.
There’s one nice addition which is rarely seen on a power amp; a headphone socket on the front panel for late night listening. Sorry – this review is decidedly headphone free as I only used the speaker outputs on the rear. As the 405 was designed to work with Quad ESL57 electrostatic speakers it seemed a sensible place to start with the Zinamp. Rated at 120W and pure Class A operation for the input stage with a cleverly biased class B output stage this is what gives rise to the Simultaneous Class A (SCA) in its nomenclature. Both stages are in the same feedback loop, so any error is corrected, and any notch or crossover distortion should be completely eliminated. Well, that’s the theory anyway.
Sound quality
With that in mind I started with Don Maclean’s Starry Starry Night, an oft-hackneyed track, but a musical ode to Vincent Van Gogh, and in its way quite a magical tribute to another artist. Maclean’s voice was very clear. The guitar obviously separate but connected, and the two together occupied the same space, just as if Maclean was sitting on a stool in front of me. The wooliness of the 405 was entirely absent. With the SCA Power Amplifier Zin have managed to really open up the capabilities of current dumping and allow the smallest nuances to shine through. The occasional scrape of finger on string was laid bare in an entirely natural way, and the frequency extremes (not so extreme in this case) were handled with consummate ease. There was a slight edginess in Maclean’s voice, and it was clear that this particular song was quite emotionally charged for him.
Moving on to rather more complex material with Oscar Peterson’s Night Train (Verve V6-8538, 1963), here there were a lot of complex rhythms going on, counterpoint, high treble (Ed Thigpen) and deep bass (thanks to Ray Brown). If anything, once the volume was wound up, this was likely to show up any electronic nasties as, despite the stuff going on it is a very open and natural recording.
I have to say I was rather surprised at how easily the Zinamp coped with this material. OK, so it’s not a double orchestra and double choir, but there’s a lot happening, and the Zinamp allowed all the small details, the subtle nuances (brushes and caressed hi-hat) through and managed to recreate the space between tine instruments with remarkable coherence. This suggests that the signal’s path through the amplifier is phase-correct at all times. With no intermodulation distortion, and also a remarkably low background noise – well, none in fact (not through the ESL57s anyway).
The other nice aspect to the overall presentation was that the SCA Power Amplifier managed to get the electrostatics to produce rather nice deep bass, so much so that I found myself wondering whether the original (and perhaps later) 405 / 306 designs had missed a bit of a trick here. I’ll need to quiz Nick at Zinamp and find out how / why his ‘little’ amp manages to seemingly extend the bottom end with these traditionally difficult speakers.
Jane Siberry’s album When I Was a Boy was a controversial release way back in the 1990s, and has a quite amazing range of dynamic contrasts, with choir, heavy drums, and very open ethereal soundscapes, particularly in the opening track Temple. If anything was going to upset the Zinamp’s rather well-laid-out applecart this was a sure contender. Later in the album Love Is Everything conjures a completely different mood – softer, more intimate, and more immediate.
The SCA Power Amplifier handled both without fuss, drama or adding anything unwanted to the mix. The power of the drums and the comeliness of Siberry’s voice were accessible in quite a rare way. Presentation was not just matter of fact as in don’t worry; I can handle this, but in a way which let the power and anger of Temple through, and which laid bare the anguish in Love Is Everything. The whole structure of the music, the emotional content and the ability to connect the medium to the listener was really quite beguiling.
Purcell’s Come Ye Sons Of Art, in this instance the Bach Guild’s recording from 1972 (HM-14SD), with Alfred and Mark Deller taking the countertenor parts, is still a fresh and vibrant recording, and having just cleaned it on the Humminguru Ultrasonic record cleaner has acquired a new lease of life. The voices soar and are the ideal complement and foil to the Oriana Concert Orchestra. There’s a clarity and immediacy to this simply-done two-mic recording and you really are drawn into the antiphonal musical interplay between them, and between them and the orchestra. If anything, my grin widened to aching-point when I played this through the SCA Power Amplifier, and a second playing only reinforced the first impression.
Next, something rather more complex: La Nativité du Seigneur by Messiaen, the recording by Ferdinand Klinda on Supraphon SUA ST-50750. Huge organ forces are at play here, with sparkling upper pipework and massive deep and powerful pedals all combining in this tsunami of sound. It’s not easy music, but there’s something absolutely fantastic about it.
Again, nothing flustered the Zinamp SCA Power Amplifier. The depth, power and weight were there as was the airiness of the upper regions. Nothing became clouded or blurry, and even the acoustic of the St Nicholas Church in Prague remained in focus. The final movement Dieu Parmi Nous is a masterpiece of counterpoint and drama. The whole presentation was utterly engaging and with the volume waaaay up it really was a totally immersive listen.
Looking through the other twenty or so recordings which were auditioned in evaluating this amplifier, there was a real breadth of material. The Zinamp SCA Power Amplifier coped with it all with aplomb. It’s unfussy, transparent and utterly engaging. Its ability to manage and recreate huge dynamic contrasts is also commendable, and its ability to capture and present really small details is also top-notch.
I did also try other speakers. The venerable Calindas came out of retirement, as did the Impulse Lalis and a pair of Reference Audio mini monitors. The Zinamp never failed to please. It managed to generate a really nice balance of extended highs coupled with a transparent and very open midrange and nice (not overblown) bass weight and depth. Interestingly, the SCA Power Amplifier has fully active speaker protection which should protect your beloved transducers from accidental damage in use. There is also an auto-on/off feature (awakened when the input sees a small signal) if you inadvertently leave it on for more than 30 minutes with nothing playing. Saves a bit of energy in these eco conscious days.
Conclusion
For an all in one package the SCA Power Amplifier is a winner, and if your’e not after more than three inputs then look no further. It’s decidedly speaker-unfussy and seems to manage to perform and wring the best out of whatever is connected to it. Just don’t expect it to cover up flaws in ether speakers or sources as it’s revealing enough that you’ll notice both rather quickly. Highly recommended.