Robert Deutsch

Although the term "professional" is often used as part of model designations in consumer electronics, the actual overlap between the audiophile consumer market and the real pro market is quite small. There are speakers in common use as studio monitors that no self-respecting audiophile would want to be caught dead listening to, and the typical audiophile loudspeaker would go up in smoke if asked to pump out the kind of volume that pro application routinely demands. To a lesser extent, the same applies to amplifiers: pro is pro and consumer is consumer, and ne'er the twain shall meet.

How important is the use of balanced circuit typology in the design of preamplifiers and power amplifiers? Ask the top audio designers (I didn't, but just play along, okay?) and you'll get a wide variety of opinions. Some reject the balanced approach outright, arguing that it represents a needless duplication of circuit components, and that better results can be achieved if the same attention and resources are devoted to perfecting a single-ended circuit. In his provocatively titled article "Balance: Benefit or Bluff?" (Stereophile, November 1994, p.77), Martin Colloms questioned the advantages of balanced designs, suggesting that while the results may be better in certain respects (eg, noise level), the reproduced sound may suffer in other, perhaps more important ways (eg, rhythm and dynamics).

I remember having a conversation with an audiophile some time ago about the thorny subject of choosing an amplifier. He was convinced, on the basis of an article he had read in Stereo Review, that all amplifiers of a given power rating sound pretty much the same. Although he was sufficiently well off to buy just about anything on the market, he didn't want to waste his money. He chose the amplifier for his system by going through the Audio Annual Directory Issue, calculating the price:watt ratio for each amplifier that was listed, and then bought the amplifier with the lowest price/watt figure that had enough power to drive his speakers. He didn't do any comparative listening and didn't consider buying anything that cost more for the same power, because he knew already that it wouldn't sound any different.

Founded by Nelson Pass in 1974, Threshold is one of those companies audiophiles tend to take for granted. Best known for the much-imitated Stasis (sliding bias) amplifier designs, Threshold became one of the industry leaders during the early 1980s. Since then, they've been upstaged somewhat by such rivals as Krell and Mark Levinson, and the public's impression of the company's stability wasn't helped by the departure of several of its principals, including Nelson Pass.