Tube Preamp Reviews

For the past several years, rather than let an active phono preamplifier do all the work, I've preferred to use step-up transformers with low-output moving-coil cartridges. There are some good active stages out there—the Linn Linto comes to mind, as well as the Naim Prefix and the MC phono boards for the DNM 3-C preamplifier—but it's my experience that trannies let the music breathe a little better.

But because I'm not an engineer, and because the old-fashionedness of the transformer approach at times leaves me feeling somewhat insecure, I'm always happy when someone who really knows what he's doing throws in his lot with the iron men. And so it goes with Tim de Paravicini of EAR.

de Paravicini points to a number of solidly technical reasons for letting a step-up transformer provide the first 20 or so dB of gain for a low-output cartridge. "The problem with active devices is they're noisy," he says. "A properly designed transformer does it with much less noise." He also suggests that a transformer recovers, rather than wastes, all of a cartridge's delicate output signal, and provides better electrical damping, too.

de Paravicini knows whereof he speaks, having been hired at a tender age by Luxman in Japan to design amplifiers and transformers. Even before then, beginning at age 13, he was teaching himself the basics of transformer design by dissecting other people's discarded electronics. "When they were wax-impregnated, it wasn't that difficult," he says. "I could melt the wax and tinker—and then buy more junk, and tinker all over again."

At Luxman, de Paravicini remembers, there was one Japanese engineer in particular who encouraged the young emigrant's interest in transformers, and from that point forward he never turned their design over to someone else: "Doing it myself gives a greater level of control over the finished product."

Is there anything in particular that stands out in the speccing of a good trannie?

"No one thing, really," de Paravicini says. "It's a collection of everything. Yes, you have to get your sizes right, and your cores. And you have to be aware that there are a great many specific methods of winding: The textbooks only speak in generalities.

"Making good transformers is quite a bit like other specialist trades, I'm afraid: It's a black art."—Art Dudley