Z-Systems rdp-1 digital preamplifier 1998 Editor's Choice
If there's one aspect of the high-end obsession that perplexes "civilians," it's the fact that our preamplifiers and amplifiers don't have tone controls, let alone that flashing-light focus of the mid-fi rack system, a graphic equalizer. I have a confession to make: I once owned an equalizer. In addition, my first amplifier, a Kenwood integrated that I bought in 1969, sported tone controls; my first high-end preamplifier, a Lecson AC-1, also did so; and I used those controls!
But as my musical and sonic tastes matured, I found I made use of them less and less. Yes, I could "correct" the tonal balances of recordings, but I found that to do so, particularly with the equalizer, diminished the musical magic. So when, in the late 1970s, I bought my first true audiophile preamp—a Meridian 101 that offered just source selection and control of volume—I didn't miss what I never used. And the preamplifiers I've owned or used in the two decades since then—PS Audio IV, Exposure 7, Krell PAM-3 and KRS, Ben Duncan AMP-01, Audio Research SP8 and SP10, Conrad-Johnson PV7, Mod Squad Passive Line Drive, McCormack TLC-1, Mark Levinson No.38, '38S, and '380s, Meridian 518—have featured many things, but not a tone control was to be found among them.
I suspect that all of us have similar tales to tell. Forget the old audiophile wives' tales of "tone controls introduce phase shift" (they do, but so what?). The audiophile's disdain for tone controls is a demonstration of the Second Law of Thermodynamics: If you try to change one aspect of an experience for the better, you will worsen the overall experience. The only way to make something better is to address its totality. Don't buy an equalizer, buy a better-sounding preamplifier.
But then, in the July '98 Stereophile, Kal Rubinson reviewed the $5000 Z-Systems RDP-1. Here is a digital "preamp" that offers digital source selection and a well-engineered digital-domain volume control. Nothing new in that: I've been using the Meridian 518 in that role for a couple of years now. But the RDP-1 also offers what Z-Systems terms a "Transparent Tone Control."
"Pshew-yeah," my quarter century of audiophile conditioning prompted me to respond when I first read those words. But then I tried the RDP-1. I used it to apply some mild EQ to tonally distressed recordings. I used it to equalize out of existence some room anomalies that I hadn't been able to eliminate despite hours, even days, of moving speakers around. I used it to provide some tonal shaping on my live recordings. And no matter the circumstance, other than the desired change in sound, the musical magic remained intact.
So Z-System's RDP-1 is my 1998 Editor's Choice. With its transparent control of tone, it points to a future in which audiophiles can eat their cake and have it too.—John Atkinson