CES 2012 Report – Dick Olsher on Tube Gear

CES is no place for someone looking for audio certainty in an uncertain world. The clash of competing designs is most evident in the loudspeaker arena, which resembles a dog show with its bewildering range of speaker and woofer “breeds,” from the miniature to the gigantic. The situation is almost as perplexing when it comes to amplification. For example, I didn’t expect to have to cover Class D amplification in the context of tube audio, but Rogue Audio’s new stereo tube/Class D hybrid amps, the 200Wpc Medusa ($3995) and the 100Wpc Hydra ($2995) bridge the gap between solid-state switching amplifiers and tubes. This appears to be part of a recent trend, a Gen II effort, if you will, aimed at humanizing Class D designs, though a triode front end represents only one possible approach. Rogue Audio’s Mark O’Brien selected a pair of Hypex Class D MOSFET modules since these sound pretty good already as they maintain constant THD levels independent of frequency and allow 2nd and 3rd harmonics to dominate. The triode front end attempts to add some tube magic to the mix. Paired with Eggleston Andra III loudspeakers, Hera II preamp, Ares phonostage, Spiral Groove turntable, Mac Book with Ayre QBq DAC, and TEL Wire cable, the Medusa acquitted itself exceptionally well: the bass punch you would expect from Class D together with the soundstaging and dynamic nuance tubes are known for.

The old adage—lead, follow, or get out of the way—is very much in EveAnna Manley’s playbook. Of course, her preference is to lead with products such as the Stingray iTube integrated amplifier with iPod dock and RF and IR remote control, manufactured with pride in Chino, California. If you’re fishing for an affordable and flexible tube phono stage, try the Manley Labs’ Chinook priced at $2250 (or as EveAnna puts it, Chino-OK). The Chinook is said to epitomize the sound of the more expensive Steelhead and also uses a 6922 dual triode for gain together with passive RIAA. There are 32 loading possibilities for MC cartridges. Gain is selectable via internal DIP switches at either 45 or 60dB. The output stage comprises another 6922 configured as a White follower for beefy current drive capability and exceedingly low (50 Ohm) output impedance.

PrimaLuna’s Dialogue line now has a new member—the Dialogue Premium integrated amplifier ($3199). The new all 12AU7-based front end is said to result in a wider, more linear bandwidth. In addition to accommodating the usual power tube options, the adaptive autobias circuit is also comfortable with the Russian KT120. Notable enhancements include an Alps motorized potentiometer, premium caps and resistors in critical circuit locations, and an AC-offset-killer circuit for the power transformer.

VTL’s new addition to its Signature line, the S-200 stereo amplifier ($10,000), and the new S-400 Series II stereo reference amplifier ($33,500) may well prove to be leaders in their respective categories. Both are switchable from tetrode to triode mode. The S-200 Signature is no slouch at 200Wpc tetrode mode and 100Wpc in triode, while the S-400 Series II is even beefier, rated at 300Wpc in tetrode and 150Wpc in triode. These are sophisticated designs featuring fully balanced differential circuitry, shorter feedback loops, Mundorf silver/oil caps in the signal path, microprocessor-controlled auto bias and fault-sensing, regulated screen supplies, and interleaved output transformers. A user-adjustable damping-factor control offers flexibility for speaker matching, with three settings. VTL’s president, Luke Manley, said that “the new S-200 combines all our latest Signature amplifier technology into a single chassis,” With regard to the new S-400. Manley added that “it seems counter-intuitive that a high powered amplifier can sound as fast as a small one, yet the new S-400 possesses the speed and agility of low-powered amplifiers, while still being able to scale up very quickly and effortlessly, with a sense of almost limitless power.” I was most enamored with the sound of the S-400 Series II driving the Rockport Technologies Avior speakers ($29,500). The rest of the system consisted of the VTL TL7.5 Series III reference line preamp ($20,000), VTL TP6.5 Signature phono preamp with mc step-up ($10,500), dcS Paganini DAC and player, Spiral Groove SG-1.1 turntable with Centroid arm, and cabling by Transparent and Nordost.

Welcome back Bob! Bob Carver LLC is really the tale of two Bobs: Bob Carver the designer, and Bob Farinelli the business and marketing hub. On display were the Black Beauty 305 monoblocks ($12,900). The Class AB, fixed-bias, push-pull output stage uses three pairs of KT120s for an impressive power delivery of 305W into 8 ohms, 330W into 4 ohms, and 290W into 2 ohms. The B+ voltage is an eye-popping 765VDC, but each tube only idles at about 14W for long tube life. I’m here to tell you that in the case of Black Beauty, beauty is more than skin deep. The design features some ingenious touches such as a 6AL5 dual-rectifier-based DC restorer circuit which clamps down the KT120’s fixed bias voltage to its reference value. As a result, output tube matching is not a requirement. Mated with King Sound electrostatics and Purity Audio Design’s Silver Statement line preamp, Black Beauty acquitted itself very nicely. Look for a review this year.

Conrad-johnson, apparently responding to numerous customer requests, unveiled a stereo version of the ART monoblock amplifier. The ARTsa ($18,500) is a 140Wpc all-tube amp that features the same circuit and parts quality as its bigger brother, though the M8080 single triode was replaced by a 6189 twin triode to accommodate two channel operation. Coupled with a CJ ET5 line preamp, it produced a lovely soundstage driving a pair of NEAT Acoustics Ultimatum XL loudspeakers.

Air Tight’s Mr. Muira is a long time fan of the Ultra-Linear output stage, and I’m sure that David Hafler is smiling down from tube heaven upon the ATM-3011 monoblock amplifier ($50,000). After all, numerous Dynaco designs as well as a tube classic such as the Harman Kardon Citation II can’t be wrong. The ATM-3011 is intended to drive real world loads without any difficulty. Rated at an honest 200W, its THD is still below 1% at full power (1 kHz). Mr. Muira favors the Svetlana 6550 and deploys three pairs in push-pull configuration per monoblock.

Concert Fidelity’s CF-080LSX line preamp ($20,000) represents a fascinating minimalist design. It uses tube rectification and a pair of 12AU7 triodes for gain. Unusually, the entire line stage circuit is mounted on the rear panel. In this way, designer Masataka Tsuda has succeeded in shortening the entire signal path to under five inches, a method he has dubbed “Direct Signal Path Technology,” which he believes is responsible for preserving signal purity. Extensive design work has also gone into a unique volume control, which is said to be superior to other IC-based controls, or for that matter, resistive controls. As far as remote-controlled input selection, the decision was made to avoid multiple relays since they take space and make the circuit loop larger, and instead use an IC that is seldom used in audio applications. Look for a review this year.

While Cary Audio’s gear was in several locations throughout the show, I only spent time listening to it in the Adam Audio room, where it was doing a spectacular job partnering Adam’s Column Mk3 speakers. The Cary Audio gear consisted of the SLP-05 preamp, SA-200.2 power amp, and CD-500 CD player.

One of the best sounds of the Show was to be had courtesy of Einstein’s 6C33C-B based 60Wpc OTL monoblocks ($40,000) driving the 93dB sensitive Acapella High Violoncello II loudspeakers. The combination of tubes, spherical horns, and ionic tweeters certainly pushed all of my buttons.

I never miss a chance to audition LAMM Audio Laboratory’s ML3 Signature monoblock amplifier ($139,290). At its best, partnered with compatible gear, it is capable of unleashing the music’s full emotional content. Needless to say, I was in no hurry to leave. The rest of the system consisted of the LAMM LL1 Signature line-level preamp and LP2 phono preamp, Wilson Audio MAXX 3 speakers ($68,000), NeoDio NR22T transport ($13,300) and NR22D DAC ($12,000), Onedof turntable ($150,000) outfitted with Graham Phantom II tonearm ($4,900) and Benz Micro LP-S cartridge ($5,000), Harmonic Resolution Systems stands and isolation bases, and Kubala-Sosna Elation series interconnects and speaker cable. Total system cost: $599,000!

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Dick Olsher’s Best of Show

Best Sound (cost no object)

Without a doubt, the MBL 101 X-treme system driven by four model 9011 mono amplifiers. Definitive hardware in the service of music. Auditioning this system should be on everyone’s bucket list.

Best Sound (for the lowest price)

The Adam Audio Column Mk 3 loudspeaker ($7000 for passive version), featuring X-ART tweeter and midrange (better known as Heil Air Motion transformers), powered by Cary Audio electronics.

Most Significant Product Introduction

The MBL Corona line, available at several system price points. It brings MBL’s “Radialstrahler” bending-wave technology within reach of the common man, and showcases their excellent linear analog switching amplification.

Greatest Technological Breakthrough

D2Audio’s (a division of Intersil) audio-enhancement algorithms, the “Mighty Cat,” tuned by Mark Levinson based on his mastering experience. Aimed at bridging the gap between high-end audio and mass-market sound systems.

Most Important Trend

The continual improvement of Class D amplification, most clearly evident with Rogue Audio’s hybrid designs and MBL’s linear analog switching amplifiers.