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The original version of this has been my reference amplifier since I reviewed a pair of them two years ago (Vol.9 No.1), and although it has since seen a number of small but significant changes, I felt I couldn't part with mine for long enough to get them upgraded. Finally, when I saw that I was going to be out of town for a week, I sent them back.

What I got in return was, for all intents and purposes, a pair of different amplifiers. On first listen, right out of the box, they sounded quite bad—harsh, rough, and…

Editor: Since J. Gordon Holt's description of the SWDT (straight wire differential test), there have been many comments and inquiries directed both to Stereophile and directly to me concerning this test. I will try to answer most of these in this catchall commentary.

The starting point is that it is very difficult to compare amplifier A with amplifier B to make a quality assessment. The conventional A/B test, or any comparison, may indicate that the amplifiers are different, but how can one determine which is "best"? "Best" is a matter of judgment, and even…

Madrigal's chief executive officer is known for working well into the night, but that's been a goal of his since boyhood. For many years he dreamed of becoming a professional guitarist, and even dropped out of Yale to satisfy a ravenous musical appetite. "Enough of trying to be a Renaissance man," Phil Muzio recalls thinking at the time. His aim was to be out there on the bandstand making music.

Muzio was born in 1954 and grew up on his family's 47-acre vegetable farm in North Haven, Connecticut. (The land, which his Sicilian-born…

Muzio: We're working to be compatible with every known valid technology. We don't experiment with our customers on immature technologies. Everything we've always done has been a little bit late. We didn't introduce our first Levinson digital processor until 1990, and it was after we had gained experience with Proceed processors.

Lander: You've said your product-development cycle runs up to 18 months or more. How do you know when it's time to begin work on a Levinson product that incorporates a new…

Kathleen and I, having flung ourselves into single-ended's embrace, have become, to some fashion, quite experienced. I've described the purity of presentation available with the Wavelength Audio Cardinal XS monoblocks when coupled with the Swiss-made Reference 3A Royal Master Controls in these…

The MI Ag works at least as well on the Wavelength XS monos, and we'll see what happens with the Audio Note Kasai. I'll try them with push-pull eventually—I've got…

It was a great pleasure auditioning so many 300B tubes. Here are thumbnails of our experiences with them.

Western Electric 300B: In the way that audio can be anthropomorphic, I'll say these guys are suave, baby. Dean Martin, Sammy, and Frank—the rat pack. The Pierce Brosnan double-oh seven of 300Bs. Or a Ralph Lauren Polo type. Older guy—an arbitrageur—with impeccable style and the cash to indulge it. The tubes are beautifully made and presented—check the serial number on the tube and its box for authenticity. (This is one tube sure to be knocked-off.)…

When I measured the Wavelength Cardinal, another single-ended tube amplifier, I commented on its poor test-bench results and noted that it might have been a hot design in 1940. It's only fair that I make the same comment about the Jadis. The Jadis also measures worse than the Wavelength in one very significant way; it has a severely compromised bass response. Though I haven't heard the Jadis horn loudspeaker, which JS used in his review, many commercial horn loudspeakers don't have a very extended bass. [Note JS's auditioning comments about the system'…

The amplifier measurements here were made using the tubes JS found to be the best-sounding: Western Electric 300B, GE 5692, and RCA 5R4GB.

The Jadis SE300B was warmed up for 1 hour at 1/3 of its rated maximum power of 10W. Nothing unusual was observed in this pretest; the 300B ran typically hot for a tube amplifier. Its input impedance measured a high 135k ohms. The output impedance was 2.5 ohms at 1kHz, 2.7 ohms at 20kHz, and 0.76 ohms at 20Hz. This amplifier's frequency response will be very dependent on the loudspeaker load. Voltage gain into 8 ohms was…