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The Fifth Element #90 Contacts

Sidebar: Contacts

DHDI/Delta H Design Inc., 13900 Marquesas Way #6005, Marina del Rey, CA 90292. Tel: (310) 581-2331. Web: www.deltahdesign.com

Tellurium Q Ltd., The Willows, Bonds Pool, Langport, Somerset TA10 9QJ, England, UK. Tel: (44) (0)1458-251-997. Web: www.telluriumq.com. US distributor: Fidelis High-End Home Audio & Theater, 460 Amherst Street (Route 101A), Nashua, NH 03063. Tel: (603) 880-4434. Fax: (603) 880-4433. Web: www.fidelisav.com

Thöress 300B monoblock power amplifier Page 2

A note about gain: According to Reinhard Thöress, the input sensitivity of his 300B amp is intentionally low, to prevent excessive preamp noise in systems that include the high-efficiency speakers with which most Thöress amps will surely be used. The amp's low input sensitivity has the additional benefit of allowing the user to operate his or her preamplifier volume control within a moderate to high portion of its range, where channel tracking is optimal—and that certainly proved true in my system.

Listening
The first thing that impressed me about the sound of the Thöress 300B was its…

Thöress 300B monoblock power amplifier Specifications

Sidebar 1: Specifications

Description: Monophonic single-ended-triode tubed power amplifier. Tube complement: one 300B, two EL803S. Input: 1 line-level. Maximum output power: 8Wpc into 16 ohms (12dBW ref. 1W into 8 ohms). Input impedance: 100k ohms. Input sensitivity: 3.25V RMS. Output impedance: transformer matched to 4, 8, 16 ohms (see text).
Dimensions: 13.4" (343mm) H (including tubes) by 5.9" (152.5mm) W by 23.3" (597mm) D (including output terminals). Weight: 28 lbs (12.7kg).
Serial numbers of units reviewed: None found.
Price: $12,995/pair. Approximate number of…

Thöress 300B monoblock power amplifier Associated Equipment

Sidebar 2: Associated Equipment

Analog Sources: Garrard 301 turntable; EMT 997, Thomas Schick tonearms; Ortofon SPU-A & SPU 95th Anniversary & CG25i, Miyajima Premium BE Mono II, EMT OFD 15 & TSD 15 pickup heads.
Digital Sources: Halide Designs DAC HD USB D/A converter; Apple iMac G5 computer running Audirvana Plus v.1.5.12; Sony SCD-777ES SACD/CD player.
Preamplification: Hommage T2 step-up transformer, Shindo Masseto preamplifier.
Power Amplifiers: Shindo Corton-Charlemagne (monoblocks) & Haut-Brion.
Loudspeakers: Altec Valencia, DeVore Fidelity…

Thöress 300B monoblock power amplifier Measurements

Sidebar 3: Measurements

I performed full sets of measurements on both samples of this retro-styled amplifier, using Audio Precision's SYS2722 system (see www.ap.com and the January 2008 "As We See It"). As instructed in the manual, after inserting the tubes and running each amplifier for a while to make sure everything was at the optimal operating temperature, and with no signal applied, I rotated the rear-panel knob of each monoblock to minimize measured hum in the output. This was a straightforward operation and, as you can see from the signal/noise measurements later in this report,…

Music Matters in Denver Tomorrow & Wednesday

High-end audio retailer Listen-Up is holding two evenings of music seminars and audio demonstrations at its Denver location (685 South Pearl Street) Tuesday April 7 and Wednesday April 8, from 5pm to 9pm. As well as Stereophile editor John Atkinson (above left) and Shawn Britton of Mobile Fidelity Sound Labs (above right), who will be talking about how recordings are made and how to make them sound the best in your home, presenters will include Sandy Gross (GoldenEar), Wendell Diller (Magnepan), Paul Barton (PSB Loudspeakers), Owen Kwon (Astell&Kern) Doug Henderson (Bowers & Wilkins…

AVI's Grand Opening in Marin

Yet another Bay Area audio retailer has defied industry trends by moving from home-based business to a storefront and simultaneously revamping its product line. Audio Video Integration (aka AVI Marin) celebrated the Grand Opening of its new San Rafael 6000ft2 retail store and 3000ft2 warehouse on April 2, 2015 via a ribbon-cutting ceremony officiated by San Rafael Vice Mayor Andrew McCullough. Even before the ceremony got underway, and for several hours thereafter, a host of loyal customers, friends, and well-wishers began to ogle the store's capacious layout and multiple audio and AV…

Doug Sax: From Direct-Cut to Compact Disc

As reported by Michael Fremer on AnalogPlanet.com, legendary mastering engineer and co-founder of Sheffield Lab, Doug Sax, passed away on April 2. Doug had been suffering from cancer and would have been 79 on April 26.

Coincidentally, we had just posted J. Gordon Holt's October 1982 review of the Sheffield Track Record, which Doug had cut direct-to-disc. This reminded me that Robert Harley had interviewed Doug in the October 1989 issue of Stereophile; rereading that interview reminded me that in September 1984, I had published an interview with Doug in the magazine Hi-Fi News, which I…

Computer Audio Seminars in Canada This Weekend

Saturday and Sunday, April 11 and 12: Fillion Électronique will host seminars on the fundamentals of computer audio, with specific focuses on digital-audio file formats and networking strategies. Saturday's seminar will begin at 10am and will be held at Fillion's Laval location (2323 Laurentides Highway), while Sunday's seminar will begin at noon and will be held at Fillion's Montréal location (5690 Sherbrooke East).

AudioQuest's Frédéric Pinsonneault will be on hand to answer questions and provide information on the software and components needed to transform a computer into a high-…

Who's Right? Accuracy or Musicality

Many years ago, the now-defunct Life magazine ran a feature article about science and its sacred cows, in which a cartoon showed a huge inverted pyramid-shaped structure of great complexity, tapering downward to a single support at its base: a toothpick. The toothpick was labeled "basic premise," the inverted pyramid was the entire body of scientific knowledge.

Everything we do or think or know is based upon assumptions, some of which are rather more justified than others. When we set the alarm clock, we assume there will be a tomorrow. When we reach for the car's brake pedal without…