I measured the Definitive Technology StudioMonitor 55 with DRA Labs' MLSSA system, a calibrated DPA 4006 microphone for the speaker's frequency response in the farfield, and an Earthworks QTC-40 mike for the nearfield responses. I estimated the SM55's voltage sensitivity at 87.6dB(B)/2.83V/m, which is reasonably high but significantly below the specified 90dB. The SM55's impedance is specified as 8 ohms; my plot of its impedance magnitude (fig.1, solid trace) remained above 6 ohms for most of the audioband. Though there are minimum values of 3.8 ohms at 205Hz and…
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Going to see Les Paul during his final years, playing every Monday night at the Iridium club just north of Times Square in NYC was always a good time, not only for the music—and to be truthful, by then Les’ arthritis had robbed him of his best chops—but also for his playful, well–meaning, semi–lecherous sense of humor. It’s a point made by many of the interview subjects in Thank You Les, a new CD/DVD package that celebrates not only Paul who died in 2009 at age 94, but also his longtime sideman, guitarist Lou Pallo. Keith Richards, Billy F. Gibbons, Slash and Steve Miller are the more famous…
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!
I can't imagine what went wrong.
Description
The EHF-100…
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…