Amplifiers included a Mark Levinson No.27 (used exclusively with the Quad ESL-63 USA Monitors) and a Krell KSA-250. In addition, I used a very inexpensive Lafayette Criterion SR 10A receiver, just to test Kevin Voecks's suggestion that the Snell Type E/IIIs could also perform with lesser electronics. The Quads and the Snell A/III's midrange/tweeter section were driven by the Levinson No.27 via 15' runs of Monster Cable. Because the two systems were bi-amplified, the Quad/Gradient subwoofer and the A/III's woofer section were driven by the Krell KSA-250 via HF10C…
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Sidebar 3: Measurements
Before Tom Norton sent the E/IIIs off to Larry for auditioning, I ran them through a subset of my basically standardized set of tests. Fig.1 shows the speaker's impedance and electrical phase. (The twin curves in the treble show the tweeter-level control set to its minimum and maximum positions.) Dropping to 4 ohms or below only in the upper bass (and the high treble when the level control is set to its maximum position), the E/III is reasonably easy for an amplifier to drive. Even relatively inexpensive electronics—vide LG's antique Lafayette receiver—should have…
What's this? A review of a $3000 moving-coil step-up transformer in this digital day and age? Yep. Although the market for such a product is small, the fact that the Expressive Technologies SU-1 step-up transformer enters previously uncharted state-of-the-art territory warrants these pages of editorial space. Furthermore, LP playback appears to be alive and well at the upper end of the high-end spectrum, a market segment addressed by the SU-1 (footnote 1).
Before getting to the SU-1, a few words about Expressive Technologies are in order. In many ways, they are like the small tweaky…
Sidebar 1: Specifications
Description: Moving-coil step-up transformer: Voltage gain: 28dB. Turns ratio: 25:1. Input impedance: 75 ohms. Recommended preamp input impedance: 47k ohms, 100pF. Frequency response: 0.1Hz–250kHz, +0, –3dB. Phase shift: <3° at 20kHz. Group delay variance: <100;us (20Hz–20kHz). Noise: >–100dB (referenced to 0.5mV). Maximum input voltage: 1V. Maximum output voltage: 25V.
Dimensions: 19" W by 5.4" H by 8.25" D. Weight: 35 pounds (net).
Price: $2950 (1992). Approximate number of dealers: 5.
Manufacturer: Expressive Technologies, P.O. Box 6401,…
Sidebar 2: Review System
I auditioned the SU-1/IC-1 combination over the past few months. Phono preamps used in conjunction with the SU-1 included the Audio Research SP11 Mk.II and a Mod Squad Phono Drive, all driving (independently) an Audio Research LS2 line-stage preamp. Turntable was the Well-Tempered with its tonearm modified by LP Labs (see Vol.15 No.1, p.224).
Loudspeakers were primarily Hales System Two Signatures, augmented with a Muse Model 18 subwoofer. Power amplifiers were my long-term favorites, the VTL 225W Deluxe monoblocks, or the two solid-state amplifiers…
Sidebar 3: Measurements
When I measured the SU-1, the results appeared to be more related to the test setup than the SU-1's intrinsic performance. Just as there was a large variability in sound quality depending on the phono preamp used, the measurement results were highly dependent on the test conditions.
I initially measured significant rolloffs at the audio-band frequency extremes—down 2dB at 20kHz and nearly 3dB at 20Hz. These rolloffs would be highly audible, yet no rolloff was suggested by my auditioning. The cause of the measured rolloff was twofold. The 25 ohm source…
At a "Meet the Designers" panel discussion at the 1992 Los Angeles Stereophile High-End Hi-Fi Show, I asked a group of successful digital designers (footnote 1) each to state how much of a digital front end's sound quality they believed was due to the transport, digital processor, and interface between the two. There was virtual unanimity: Nearly everyone agreed that a digital processor accounts for about 50% of a digital source's sound quality, the transport 30%, and interface 20%.
These rough figures from my straw poll corresponded closely with my own experience: The digital processor…
Many products have been described as having excellent build quality and fit'n'finish. The No.31 transcends such descriptions and previous assessments of product build. The lavish standard to which the No.31 is built is beyond previous measure. Even the smallest details—such as the way the LEDs fit into the front panel, or the color and grain matching between chassis parts—are executed with extraordinary precision and craftsmanship. The No.31 is a work of art.
Technical description
The No.31's stunning build quality and unique functions only hint at the sophisticated technology…
I was immediately struck by how similar my impressions of the No.31 were to those when I first heard the No.30. The qualities that make the No.30 such a great product—particularly its high resolution without being analytical—were elevated to an even higher level by adding the No.31. In fact, the No.31 proved to be as revelatory as the No.30. Together, they produced a presentation that far exceeded what I had believed to be the bounds of the Compact Disc format.
The No.31's effect on the system can only be described as magical. Even compared to other excellent transports, the No.31 was in…
Sidebar 1: Review System
Though the No.31 was auditioned primarily with the No.30 processor, it saw action with a variety of other converters. These included the Meitner IDAT, Sumo Theorem, Meridian 263, PS Audio UltraLink, and a Proceed PDP 3. I also experimented with the different interface types and will report on these comparisons.
Loudspeakers were Thiel CS3.6es, driven by a Mark Levinson No.23.5 via an 8' run of AudioQuest Sterling. The No.30's balanced outputs drove an Audio Research LS2B through short balanced lengths of AudioQuest Lapis or Diamond. A second run of…