I can't imagine what went wrong.
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The EHF-100…
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I can imagine the gaiety and mirth that filled the halls of the electronics industry in the 1950s, as engineer after bespectacled engineer realized that the transistor would soon consign to the outposts of oblivion those ancient technologies that had preceded it. Before long—surely no more than a decade—the hated vacuum tube would vanish from the Earth, along with the tube socket, the tube tester, the tag board, the high-voltage rail, and that lowest rascal of them all, the output transformer. What a jubilant time!
Most of my listening was done with the Rogers EHF-100 on the top shelf of a borrowed Box Furniture Company D3S rack. Since it lacks a phono section, and because I listen much more to LPs than to CDs or digital music files, I supplemented the Rogers with a borrowed Leben RS-30EQ phono preamplifier (which I reviewed in the November 2011 Stereophile), preceded by step-up transformers from Silvercore and Auditorium 23. As I'm presently surveying the field of contemporary loudspeakers that share the better characteristics of vintage speakers, I was able to try the Rogers EHF-100 with a greater…
Sidebar 1: Specifications
Description: Tubed integrated amplifier. Tube complement: two EF86, two 12AX7, four KT88. Line inputs: 4. Input impedance: 50k ohms. Rated output power: 65Wpc into 8 ohms (18.1dBW). Frequency response: 2Hz–100kHz, –1dB. Total distortion: <0.1% (output power not specified).
Dimensions: 17" (432mm) W by 10" (254mm) H by 16" (407mm) D. Weight: 50 lbs (22.7kg).
Serial Number of Unit Reviewed: 3036.
Price: $6350. Approximate number of dealers: 15.
Manufacturer: Rogers High Fidelity, 52 Kain Road, Warwick, NY 10990. Tel: (845) 987-7744. Web: www.…
Sidebar 2: Associated Equipment
Analog Sources: Garrard 301, Thorens TD 124 turntables; EMT 997, Ortofon TA-210 tonearms; Ortofon SPU, EMT TSD 15 70th Anniversary & OFD 25 & OFD 65 pickup heads; Denon DL-103, Miyabi Mono cartridges.
Digital Sources: Wavelength Proton, Halide DAC HD USB D/A converters; Apple iMac G5 computer running Apple iTunes v.10.2.2, Decibel v.1.0.2 playback software; Sony SCD-777ES SACD/CD player.
Preamplification: Auditorium 23 Standard (SPU version), Silvercore One-to-Ten, Hommage T2 step-up transformers; Leben RS 30EQ phono preamplifier; Shindo…
Sidebar 3: Measurements
I measured the Rogers High Fidelity EHF-100 using Stereophile's loan sample of the top-of-the-line Audio Precision SYS2722 system (see the January 2008 "As We See It" and www.ap.com). The maximum voltage gain at 1kHz into 8 ohms measured 40.15dB, close to the specified 40dB, and the amplifier preserved absolute polarity (ie, was non-inverting). The input impedance was lower than the specified 100k ohms, at 58k ohms at low and middle frequencies, dropping slightly to 51k ohms at the top of the audioband. This should not be a problem in use, though it is marginally…
I've heard a lot of great audio components over the years, but even in that steady stream of excellence, a few have stood out as something special. These are the products that, in their day, set a new standard for performance, and many of them are ones I wish I'd hung on to. Among these products are three preamps from Audio Research: the SP3A, the SP6B, and the SP10 (footnote 1). I know I'm not alone in viewing these models as classics.
Rumor has it that in the mid-1990s, when William Z. Johnson set out to design the original Reference 1 preamplifier, his jumping-off point was the SP10.…
The Ref 5 SE's performance at the extremes of the audioband, usually tube electronics' bête noir, was superb. The bass register of the organ in Charles Munch and the Boston Symphony's reading of Saint-Saëns's Symphony 3 (CD, RCA Living Stereo/Sony S70475C/88697720602), was astounding, absolutely subterranean, and the double basses had power and precision and a creamy, luscious tone. In Ataúlfo Argenta and the London Symphony's recording of Chabrier's España (CD, Decca 478 3157), the double basses had a nice, resiny woodiness and big, booming dynamics. However, the piccolos also spanned huge…
Sidebar 1: Specifications
Description: Tubed, remote-controlled line preamplifier with six sets of balanced and unbalanced inputs, three sets of balanced and unbalanced outputs, and a unity-gain Processor input. Tube complement: 6550C and 6H30P (power-supply regulation), four 6H30P (dual triodes). Frequency response: 0.2Hz–200kHz, +0/–3dB, at rated output (balanced, 200k ohms load). Maximum voltage gain, main output (single-ended or balanced input): 12dB, balanced output; 6dB, single-ended output. Distortion: <0.01% at 2V RMS, balanced output. Input impedance: 120k ohms balanced, 60k…
Sidebar 2: Associated Equipment
Analog Sources: VPI HR-X turntable & tonearm; Spiral Groove SG-2 turntable & tonearm; Triplanar Precision Mk.VII tonearm; Lyra Titan i, Grado Signature Reference cartridges.
Digital Sources: Audio Research CD8, Primare CD 31 CD players.
Phono Preamplifier: Sutherland Engineering Phono Blocks.
Power Amplifiers: VTL MB750 SE, Mark Levinson No.20.6 (both monoblocks).
Loudspeakers: Wilson Audio Specialties Sophia 2.
Cables: Interconnect: Nirvana SL, Nordost Valhalla. Interconnect: Stereovox. Speaker: Audience Au-24e. AC: Audience…
Sidebar 3: Measurements
I measured the Audio Research Reference 5 SE with Stereophile's loan sample of the top-of-the-line Audio Precision SYS2722 system (see www.ap.com and the January 2008 "As We See It," ). There was one problem: During shipping, one of the four large, 10µF Teflon output-coupling caps at the right rear of the printed circuit board had broken off. ARC sent me a replacement, along with the appropriate solder. However, although my soldering iron is temperature-controlled, it dates from a time when solder was lead-based and melted at a lower temperature. That, coupled…