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Anthem Electronics STR D/A integrated amplifier Measurements

Sidebar 4: Measurements

I measured the Anthem STR using my Audio Precision SYS2722 system (see the January 2008 "As We See It"). Before I test an amplifier, I precondition it with both channels driving a 1kHz tone at one-third power into 8 ohms for an hour. This thermally stresses an amplifier with a conventional class-AB output stage. At the end of the hour, the top panel was a warm 95.4°F (35.3°C), but the exposed tops of the internal heatsinks were too hot to touch, at 150.6°F (65.9°C). Even so, the STR has sufficient heatsinking for its rated power.

The analog inputs can be…

John Coltrane's <I>Both Directions at Once: The Lost Album</I> Debuts at Englewood Cliffs

A stunning jazz discovery presented at a historic citadel of recording technology. That event took place June 11, when the new John Coltrane recording, Both Directions at Once: The Lost Album, which will be released June 29, was unveiled at Van Gelder Studio, the fabled location where the celebrated engineer recorded many jazz masterpieces.

From the early 1950s to his death, Rudy Van Gelder recorded 1000s of sessions for such iconic jazz labels as Savoy, Impulse!, CTI, Prestige and Blue Note at his Englewood Cliffs, New Jersey studio. Notoriously tight-lipped regarding the details of his…

Recording of February 1968: Chopin; Nocturnes

Chopin; Nocturnes
Arthur Rubinstein, piano
RCA Victor LSC-7050 (2 LPs) (reissued on CD as RCA Victor Red Seal 0902 663049-2). Max Wilcox, prod.; Tom MacCluskey, Sergio Marcotulli, engs. Recorded August 30–September 2, 1965, 2 February 21, 1967.

If these Nocturnes are never played better than this, we couldn't care less. These are exquisite performances!

The recording, via RCA Victor's Dynagroove process is a far cry from the earlier excesses that gave Dynagroove its horrid reputation among perfectionists. One is simply not aware of the recording at all, as long as it is…

Audible Illusions Modulus preamplifier

Once upon a time, all audio equipment used vacuum tubes. In recent years, however, tubes have become the exclusive province of super high-end audio. It is more expensive to accomplish any particular task with tubes than with transistors, and few manufacturers (with the exception of Conrad-Johnson) seemed willing until now to refine their techniques and pare back their budgets to make tube components more affordable.

The success of expensive tube units, however, has prompted a number of manufacturers to offer "budget" tube preamplifiers. Though still not cheap, they come in at prices…

Audible Illusions Modulus preamplifier Specifications

Sidebar: Specifications

Description: Stereo vacuum tube preamplifier. Inputs for moving-magnet phono (MM), Aux, and Tape. Mute switch, remote power supply. Separate volume controls for each channel, no balance control.
Price: $450 (1984); no longer available (2018).
Manufacturer: Audible Illusions, San Jose, CA 95126 (1984). Distributor: Apax Marketing, Castro Valley, CA 94546. (1984); Audible Illusions, PO Box 2537, Daytona Beach, FL 32115. Tel: (386) 676-2004. Fax: (386) 676-0042. Web: www.audibleillusions.com.

Prokofiev For Two and a Half

Why the title, "Prokofiev for Two and a Half," for a Deutsche Grammophon recording on which Martha Argerich and Sergei Babayan play Babayan's two-piano transcriptions of music from Prokofiev's ballet Romeo & Juliet and four of his operas? Because any recording that features the outsized pianism of the great Argerich immediately becomes one of extraordinary importance for artistic resources that are inherently doubled by at least 50%.

Okay. I may have engaged in a bit of hyperbole here. But the importance of Prokofiev for Two is highlighted by the fact that DG has released it in three…

The Stereo Image

The author demonstrating stereo microphone techniques at an English audio show in 1981.

For most people the terms hi-fi and stereo are synonymous, and yet it is clear that there is still a great deal of confusion over what the word "stereo" actually means. There isn't even a consensus of opinion amongst producers of records, designers of hi-fi equipment, audio critics and music lovers as to the purpose of stereo, and considering that the arguments show no sign of diminishing in intensity, it is instructive to realise that 1981 sees both the 100th anniversary of Clement Ader's first stereo…

The Stereo Image Page 2

This position is philosophically untenable: to involve the concepts of "accuracy" and "realism" must be fallacious when discussing just one component in the reproduction chain, because you then introduce another variable: the quality of program material. If you are to assess the imaging properties of a pair of loudspeakers using music program with subjective reference to the live experience, you must know how well the stereo aspect of that live experience has been preserved on your two information channels. But you only have access to that information by listening to the program on…

The Stereo Image Page 3

Multi-Mono Stereo Recording
But, to get back to the theme of this article, how can these voltage ratios be derived? The most basic way is to take a monophonic signal and assign a voltage ratio to it by "panning" it to a position with a "panpot." This gives an image with unambiguous positioning and this panpotted multi-mono image is to be heard on any rock recording. Though it doesn't have positioning anomalies, it is no more than a slightly more complicated version of the notorious "now it's here—now it's there" ping-pong recordings of the late '50s. Despite effects such as artificial…

The Stereo Image Page 4

Spaced Omnis & the Curtain of Sound
If directional information can be represented by interchannel time delays, then would it be possible to abandon Blumlein's "amplitude for phase difference" substitution outlined last month and concentrate on the time delay information? About the time that Blumlein was experimenting with his crossed figure-of-eights in 1931, the Bell Telephone Labs in the USA derived from experimental binaural work the "curtain of sound" concept (fig.7). The overall wavefront emanating from the orchestra is sampled at a large number of coplanar points. The signals…