Lone Star Audio Fest 2010 Show Report
Text By John Semrad And Photo's Copyright
The most interesting room at LSAF this year was
put up by Emia Audio which is a partnership between Dave Slagle of Intact
Audio and Jeffrey Jackson of Experience Music. The speakers are very large
wooden horns turned from solid with a Le Cleac'h flare available from Jeffrey
and fed by 8" Lowther drivers modified with Dave's field coil motors. The
field coil power supply has a pair of eerily beautiful Western Electric
mercury thyratrons used as a full wave rectifier. The bass horn is the
BassMaxx designed by Johan Van Zyl and uses an 18" driver. The system
also sports a ring tweeter at the very top. The crossover is Slagle's
innovative design that uses only Permalloy-cored inductors. No capacitors are
utilized in the circuit.
The front end was an Artemis Labs SA-1
turntable designed by Frank Schroeder as well as Frank's Reference tonearm.
The cartridge was a Miyabi moving coil. The cartridge feeds an Intact Audio
1:50 80% nickel step-up transformer that couples to the E810F/7788 input
pentode of Jeffrey Jackson's phono pre-amp. It uses a very simple but
sophisticated direct-coupled scheme via stacked power supplies that have tv
diode dampers as rectifiers and an 0B3 that regulates the screen voltage. The
RIAA section is a 7.1k ohm LCR with Intact nickel inductors. More nickel is
used for the type 56 tube's 1:1 output transformer as well as for the power
supply chokes. The line stage driving the long cables employs a type 71a dht.
The power amps supplying the main speakers were Jackson's gorgeous design that uses a ValvoAa tube direct-coupled to the UX250 output tube. The circuit again uses separate power supplies feeding the two tubes, featuring W.E. 287 mercury vapor rectifiers for the UX250 and a 5Z3 for the Aa. The amps for the bass horn are Heathkit W4AMs built and modified by Jim Rivers of FM tuner shootout fame. They use Jim's favorite, the 7027, at the output. Intact Audio's autoformers (nickel of course) powered by Bent Audio's remote control module did volume control duty.
Emia Audio also had on static display some of their wares including an all Western Electric tube phono stage, more wooden horns for small compression drivers, another Intact Audio autoformer volume control, a very hairy stereo power amp built by Jeffrey that eventually made its way into Duke LeJeune's room and a pair of Dave's delectable 49% nickel single-ended
Norman Tracy's Audio Crafters Guild room had a nice little tri-amped system that showed off their line of amplifiers and speakers.
The digital source was an Oppo BDP-80 Blue Ray disc player. It fed into an ACG Series 1000 Direct Amp and a DEQX PDC-2.6 HD pre-amp/processor which divided power amp duty between a Series 1000 Stereo Amp with an Energy Pack power supply upgrade for the small mid-woofer and a pair of Series 1000 Mono Amps again provided with the Energy Pack upgrade used to power the subwoofers.
The compact Audio Crafters Guild twoZ monitor speakers sans internal crossovers use high-quality SEAS drivers in a very stout Baltic birch enclosure and sit on Solidsteel ZR-6 stands. The sub uses TC Sounds 10" woofers.
Affirm Audio, owned by the always amicable Bob Spence, showed a new speaker system which is a collaborative effort between himself and three highly regarded designers - Dave Slagle of Intact Audio and Scott Lindgren of Woden design, as well as Mark Fenlon of Markaudio, on whose Alpair 12 drivers the new Action 120e loudspeaker driver is based. Bob has long been a fixture on the local audiophile scene and always shows an excellent system.
The Baltic birch cabinets for the Action 120e field coil drivers are the Woden Design Pencil 12, which was commissioned by Markaudio for their driver and designed by Scott. The enclosure itself loads the driver with a combination of both transmission line and bass reflex methods. The field coils were wound by Slagle and were powered by an off the shelf laboratory DC power supply. The taller, narrower speaker is a Lotus enclosure with Markaudio CHR-70 drivers.
The rest of the system consisted of a Technics SP10 MkII direct drive turntable in a Porterhouse Audio plinth made from
Delignit Panzerholz. The tonearm is a 12" magnesium SME 312S mounting a Dynavector 17D2 Karat MkII which feeds an Intact Audio nickel moving coil step-up transformer. The phono pre-amp is an Artemis Labs PH-1 and volume control was done with an Intact Audio autoformer. The power amp is an Art Audio Carissa Signature single-ended 845 and the digital source is the Cary CD 303/200.
Randy Bankert of Sonist showed two pairs of his speakers, one the Concerto 3 and the slightly narrower Recital 3. The Concerto 3 is a bass reflex enclosure of non-resonant solid poplar and uses a proprietary treated-paper cone woofer crossed over with an AuriCap to a Fountek ribbon tweeter. The Recital 3 uses the same pure aluminum ribbon but pairs it with a 6.5" Tangband driver.
The digital front end is a Cary Audio Design CD 306 SACD player and it feeds directly into the darling little Glow Amp One integrated amplifier with EL-84 outputs and its fraternal twin which used an 832 twin tetrode for the stereo output power.
In room 213 was Kim Beumer of Crescendo Systems. Kim is a Dutch engineer who designs solid state amplifiers and electrostatic speakers. His speakers are unusual in that they use metalized Mylar diaphragms and relatively low bias voltages. They employ a 1:50 step-up transformer.
The analog front end was a Denon turntable which was connected to the Crescendo Systems PHA1 phono amplifier module that has a very accurate RIAA section. It also has switchable gain which can be tailored to accommodate cartridges of varying output levels. There was also a Toshiba XA-2 HD-DVD player for the digital source. The power amp in use was the DPA5 five channel digital amp that is rated at 150 wpc into 4 Ohms. Kim's BM5.1 Bass Management Module handled crossover duties to the subwoofer. Also on display was the Solo high-current, low output impedance solid state amplifier.
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