Not to be outdone by the audiophile crowd, an auto sound manufacturer displayed a huge metallic woofer that dangled from a crane. (The crane could be set to lift loads between 500 lbs and 3 tons.) I thought I had seen everything, but the North Hall of the Las Vegas Convention Center never disappoints!
Pass Labs’ engineer Wayne Colburn insisted that the name of their latest amplifier, the Xs, was not a pun. He spent over an hour detailing the 3-year design project that culminated in the company's $85,000/pair, solid-state, two-chassis-per-channel, class-A amplifier. Leaning on the 4.5-foot stack of the amplifier's stereo configuration, Wayne spoke about how the design was based on the results of an examination of transfer characteristics of a diverse set of gain devices, including tubes and SITs (silicon-carbide devices that are exclusive, we believe, to Pass Labs for use in audio). The output stage was designed to reproduce the transfer characteristics preferred by a panel of listeners, who lived with a variety of different output stages for a lengthy period of time.
Each Xs channel has two chassis, one for the power supply and the other for signal amplification. The amplifier acts as a voltage source, and is rated at 300W into 8 ohms, 600W into 4 ohms, and 1200W into 2 ohms. It is biased to ensure make certain that the amplifier remains in class-A mode into all loads. Each channel has 122 output devices with a total rating of 10kW, and the extensive heatsinking allows the Xs 300 to deliver 2kW into a load "all day long." Though the Xs 300 stack was a silent exhibit, the company was using the more modest $65,000/pair Xs 150s to drive the Pass Lab RM2 loudspeakers, which showed a wide dynamic range and outstanding detailing.
Ypsilon Electronics’ Demetrius Baklavas designed the new $36,000/pair Aelius monoblock amplifier. The Aelius is rated at 220W into 8 ohms, 308W into 4 ohms, and 500W into 2 ohms. It is a hybrid design that features tube inputs, hand-wound interstage coupling transformers, and MOSFET output devices wired in the same type of push-pull Circlotron output configuration that was found in some Output-Transformer-Less tube (OTL) designs. The Circlotron configuration was developed years ago by Electro-Voice, and while the Aelius's output devices are all N-channel MOSFETs, the Circlotron approach is very different from conventional quasi-complementary approaches.
Ypsilon's Demetrius Baklavas (right in photo) and Ypsilon's US distributor, Brian Ackerman of AAImports, demonstrated the Aelius amplifier to John Atkinson (left) and myselfthe amplifiers were doing a fine job of producing dynamics and superb open highs from the plasma tweeters of the new, floorstanding Lansche 7 loudspeakers.
Audio Research's Chris Ossanna proudly shows off the company's new $25,000/pair, two-chassis Reference 250 monoblocks, which employ the new KT-120 output tube. This amplifier has 50% more power-supply capacitance than their previous flagship, the Reference Anniversary 110, and uses the same type of Teflon coupling capacitors they sourced for their Reference Anniversary preamplifier. The front panel metering allows the consumer to check the bias and to adjust the speed of their response to either fast or slow.
JL Audio's home high-end audio subwoofer engineer, Brett Hanes, proudly shows off the company's new $1700 ES-112 subwoofer (wood finish) that uses clever engineering principles to coax better performance and value from a less-expensive product. The ES-112's woofer features the company's only dual-spider driver construction, a smaller voice-coil, though the cone is designed for the same 3" peakpeak excursions found in the company's flagship f212 and Gotham models. Other construction simplificationsyou change line input voltage by changing fuses in external fuse holdermake the product more adaptable for international sales. It also has a high-pass output with variable frequency crossover, which will be appreciated by those of us using subwoofers in a two-channel home audio system.
UrbanEar's Andrea Miles models their new mustard-colored Platten headphones, which list at $65. This was part of the great upsurge in headphone exhibits found in the South Hall of the Las Vegas Convention Center, or the "Zoo."
I should begin this review by confessing that I've never been a fan of subwoofers. Most subwoofer systems I've heard have been plagued by a familiar litany of sonic horrors: poor integration between subwoofer and main speakers, boom, bloat, tubbiness, slowness, excessive LF output, and an overall presentation that constantly reminds the listener he is hearing a big cone moving. To me, subwoofers often sound detached from the music, providing an accompanying thump that bears little relationship to the sound from the main speakers. Rather than revealing the music's harmonic underpinnings, subwoofers often obscure them in a thick morass of featureless boom. In addition, adding a subwoofer often destroys the qualities of the main speakers that made you buy them in the first placejust to name a few of my observations (footnote 1).