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American legends: VAC amplifiers and Von Schweikert loudspeakers

Christian Bayer, takes a music trip down memory lane for AQ as part of our series of articles on American Audio today.

It’s legends time

An audio match made in heaven: VAC amplifiers and Von Schweikert loudspeakers

How do we define a legend? The Cambridge dictionary offers an explanation that fits our bill: “Someone very famous and admired, usually because of their ability in a particular area.“ Now I feel confident to call Von Schweikert Audio (VSA) and the Valve Amplification Company (VAC) legends.

VACs mastermind Kevin Hayes always has a smile on his face. If you talk to him, he seems to truly enjoy what he has to offer to the audio world. And once you listen to his amps, his smile quickly jumps onto your face. And Von Schweikerts founder and name patron Albert von Schweikert sure is a legend and his company continues his legacy with his son Damon und his congenial partner Leif Swanson in the driver’s seats.

But let me start where my journey with them started. My first encounter with both brands took place in a large exhibition room at Munich’s High End Show a couple of years ago.

The distributor for the german speaking countries of both VSA and VAC, Michael Hannig from Ibex Audio, almost dragged me into this room because he knew, what was waiting for me – I didn’t. When I entered, I was confronted with VSA´s reference speaker, the ULTRA 11. This is a very large and tall tower loaded with fourteen drivers chassis, looking at you almost like a threat. To be more precise: The ULTRA 11 consists of two 1,000-watt powered 15″ sealed subwoofers, four 9″ reinforced ceramic mid-bass drivers, two 7″ reinforced ceramic midranges, two beryllium tweeters with a 5″ aluminum super tweeter forward firing and two horn-loaded Magnesium tweeters with a 5″ aluminum ribbon super tweeter rear firing as part of the ambient retrieval system. Too much to integrate? That´s exactly what I thought. But the opposite was true. First I stood there, thinking: “How can I sneak back out of this room without being forced to give an opinion?“ But once the music started playing my thoughts stopped and I listened in awe. I instantly had the impression of one large full range speaker and I mean ONE. The music seemed to emerge from just one source, not many, certainly not that many. It was a blessing for me as a reviewer: being able to forget about my prejudices and preconceptions and listening to what it’s all about: beautiful music – with a smile on my face.

I instantly had the impression of one large full range speaker

It would take a lot more pages to explicitly explain where the roots of that magic lie. To put it very short: ages of research, experience, listening to music and playing it plus the courage to walk new paths, that lead to proprietary solutions. In case of VSA two of those are called AIR (“Acoustic Inverse Replication“) and G.A.I.N. (Global Access Integration Network), both technologies that Albert von Schweikert developed in the late 70s. G.A.I.N. stands for a crossover technology, that incorporates psychoacoustic effects. AIR is based on a deceivingly simple preconception: that a loudspeaker should basically work like an inverted microphone. Many have tried this, few have succeeded – VSA has through further constant evolution. Leif Swanson puts it like this: “The last we want for any of our designs, is to sound like a hifi speaker.“


I was invited to Ibex Audio´s listening room to listen to yet another combination of VSA and VAC. And before I sat down to listen, I learned that VSA uses the exact same amps in their evaluation and listening room. Michael Hannig had set up his reference system consisting of the much more sane, slender VSA Endeavour SE loudspeakers that I reviewed some years ago and seemed to know so very well. Sources were the Air Force 3 Premium turntable, SAEC WE 4700 tonearm, Etsuro Urushi Gold cartridge, APL DTR-MR SACD-transport, DSD-MR DAC and DNP-SR Streamer. And then the VAC Master Pre Amplifier with Phono Stage and VAC Signature 200iQ Stereo Power Amps used in double mono configuration. Cabling was Masterbuilt Reference throughout and the components sat on a Critical Mass “Sotto voce“ Rack on CM CenterStage2 Footers.

The other magical part of that show setup was due to the amplification of VAC. But what makes VAC amps so special? Apart from the custom made transformers, choice of parts and clever circuits with 30 years of experience, one detail stands out. It is called iQ (Intelligent Continuous Automatic Bias System) and was patented in 2014. Fixed Bias was the gold standard for biasing power tubes as Kevin Hayes explained in an interview. But he puts the finger on two major drawbacks of this solution. Fixed bias cannot prevent tube drift and what is even more important, the operating points of the tubes shift upwards with the increase of volume or changes in your power line that unfortunately happen all the time. Kevin says you can clearly hear that. While we have no ways of confirming that, because we would need two identical amplifiers, one with and one without the iQ circuit, we can sure hear a sonic superiority of the VAC amps over many others of similar basic designs. Another benefit of the iQ circuit is the choice of tubes: you don’t have to buy expensive New Old Stock tubes to make it sing. Plus the iQ system defends the amp against short circuit tubes, prevents gas current run away tubes, indicates weakening tubes, and minimizes noise and distortion.


I could almost instantly dive into the music since it sounded so pure, so natural and believable.

When the music started, I quickly found that magic from the Munich Show again. I could almost instantly dive into the music since it sounded so pure, so natural and believable. It did not seem to come from technical apparatuses but appeared like it was created right there in that room for me – and Michael. It felt like Miles Davis and his band were playing the chorus of “So what“ just for us for the first time. Please don’t get me wrong: Von Schweikert loudspeakers work with many other amplifiers splendidly and VAC amplification suits a plethora of other speaker brands. But together the offer a level of coherence, immediacy and and sheer beauty, that you would have to walk a long mile to find that again. But please listen for yourself. It could be the beginning of a very long friendship.