The Vacuum Tube State of the Art Conference

Yes, passes for VSAC can be a little spendy but VSAC is a ‘specialty conference’ within the world of hifi, attendance is in the hundred’s, not thousands so the price is commensurate with what is required to put on a conference in the first place. Once inside though you’ll find lots of gear ranging from spendy to not spendy at all (think DIY as tube gear and DIY just seem to go together). You’ll also find a slate of presentations and talks on hifi, room treatments etc and some concerts. I counted 37 exhibitors in 18 rooms. Key among the seminars was “Amp Building Class” presented by the good folks from Over the course of two days (8 total hours) attendees completed the building of a nice two channel amp (pictures of one of them below) that was then their’s to keep. It was not wall to wall tubes at VSAC however, music servers were discussed in one of the seminars and many exhibitors rooms were driven by servers, next most popular was reel to reel tape and then finally vinyl – what’s up with that!? Here’s a sampling of what I saw.

Bob Hodas ( presented on room acoustics. He advises using measurements and ‘working surgically’, only address the issues that need addressing. There’s no need to implement every treatment available when just a couple will do the trick. ‘Not every corner is bad’ was an oft repeated message. Coffee tables however, those are almost always bad.

Audio Note ( offers a full range of quality gear and kits. Most of the exhibitor rooms at VSAC combined equipment from several manufactures. The Audio Note room was all Audio Note, the sound was excellent, detailed with no brightness or harshness.

Clean internal wiring gives a warm feeling while the tubes give the warm sound. This is the underside of a new 300B SE kit by Audio Note.

More fine construction was on evidence in the ‘Craftsman’s Room’.
Continuing in the DIY theme, some rooms were dedicated not to manufactures but to fellow hifi nuts who had built all or part of their own systems.

Alfred Duppke built these speakers with no baffles for the midrange and tweeter, they are simply attached to the frame in the upper part of these speakers with angle iron. The sound was er, transparent. I wonder how they would sound closer to the back wall.

Dennis Fraker built every component in this system from the music server with Lynx sound card to the speakers with 15″ woofers (my favorite) with embedded (right smack in the middle) horn mid’s. The amp power is rated at less than 1 watt. The sound was mighty fine and plenty loud.

The Exemplar Room featured one of their first music servers (a customer demanded one so they had to figure out how to make them), an Exemplar DAC, Exemplar XP2 preamp and Exemplar 300B monoblock amps using AT88’s as the ‘shunt’ in the amp circuit and Exemplar Horn speakers. Using active shunt regulation in the amps helps the amps deal with (absorb) back emf generated when the speakers are hit with reflections and sound waves generated by the other speakers in the room.

Bent audio ( specializes in volume controls only. While they have some traditional resistive controls and autoformer based preamps their flagship is these autoformer based level controls with fiber optic control. An autoformer is a transformer with multiple taps, different taps are selected to create the desired voltage/volume level a passive preamp. An autoformer based preamp with 6 inputs can be had for around $2k, standalone autoformers as shown here are about the same price.

Bottlehead used a multitude of their Sex Amps to drive a multitude of custom speakers. Here I heard the most separation between instruments and extended bass of anywhere in the show, except for what I heard next . . .

Experience Audio ( builds custom amplifiers and horn speaker systems including ones like these. Prices depend on particulars but this system (speakers only) could be had for $40k. I’m not sure if that was a ‘show special’ or typical. Sound was big as you might expect. The selection was a classical symphony (sorry I don’t know which) and the sound stage was reminiscent of an orchestra, not speakers creating an artificial sound stage, an orchestra.

The Write Sound ( room featured custom speakers with Fostex drivers modified by painting them with the EnABL pattern. This modification was invented by Bud Purvine says the internet and is a hot topic at These speakers sounded fantastic. I’ve been reviewing some outstanding Daedalus speakers that feature a modified Fostex driver as well (not like this though!). The sound was similar but I’d say the EaABL modified speakers were a little brighter. I’d need more listening to know which was better and I’d need a dose of courage to modify my drivers like this.

The ModWright room ( featured the ModWright modification of the Logitech transporter ($3600), Modwright LS-36.5 preamp ($5000), Exodus Audio UeD400-4 MCH Amp ($1945) and Keplar speakers ($1000/pair). Interconnects were by Cardas. Pictured here is Dan Wright (left) and Kevin Haskins of Exodus Audio. The speakers can also be built as a kit for about $700.

Paul Birkland of Bottlehead built the amp pictured above during the Amp Building Class. While I was in the room another Amp Building student brought in his class project and it was connected to the large Klipsch speakers. The tiny amp drove them with no problem, well there was a little problem as one of the channels was not working at first, I’m not sure what was done to bring it to life. Sound was maybe missing a little on the bass side as we grooved to some excellent Amon Tobin, but the midrange was grungy (as it should be that’s what’s on the record) and very involving. Did you notice the engraving on the bottom of that amp? It says “Pomme de Terre Gormet”, which is some sort of inside tube joke having to do with spuds (right over my head). The engraving was added courtesy of Front Panel Express (
Here’s some more Front Panel Express handiwork. Just download their free software, design the faceplate for your homemade amp, preamp, widget-whatever and for a pretty reasonable price get one or more of them shipped to your door.