Conrad-Johnson CT5 line preamplifier Sam Tellig, July 2008
I have known Bill Conrad and Lew Johnson for about 25 years. I don't for a moment think that they push up prices only to make more money. Such a frugal pair. In the official spelling of their company name, conrad-johnson design, inc., they even spell their last names entirely in lower case.
But, like other high-end audio manufacturers, Bill and Lew have to keep improving quality to keep their competitive edge. And that means buying expensive parts from esoteric manufacturers in small quantities. Fortunately, some of the technology manages to trickle down to less costly spheres.
Take the Conrad-Johnson CT5 line-stage preamplifier, which Wezz (which is how The Chief, John Atkinson, refers to Wes Phillips) flipped over exactly two years ago, in the July 2006 Stereophile (Vol.29 No.7). As WP noted, the CT5 is a simplified version of C-J's flagship, two-chassis preamplifier, the ACT2 Series 2. The circuits are similar, with many of the same parts: Vishay resistors, and hugely expensive (and huge) Teflon storage capacitors. At $8500, the CT5 doesn't exactly sell for a song, but that's only a bit more than half the price of the ACT2 ($16,000).
Bill and Lew met when they were young economists working for the Federal Reserve Bank, in Washington, DC. Note that they are economists with PhDs. If they had only MBAs, they would have put themselves out of business long ago, cheapening their products, pinching every penny, squeezing every nickel. MBAs play trickslike cutting a 1-lb bag of coffee to 11 oz, shrinking the length of each toilet-paper roll, shrinking the contents of a box of breakfast cereal. They chisel and cheat. I digress.
One marvels that Bill and Lew started Conrad-Johnson in the first place. Thirty-one years ago, many would have thought them foolhardy. But perhaps, as economists, they saw a niche. At any rate, they knew that tubes, which were then rapidly going out of fashion, were inherently more musical devices than transistors. For sure, transistors have since improved measurablyand immeasurably. But for C-J, for most of the time, tubes have ruled.
Flash back to 1977, when luminaries such as Julian Hirsch, Len Feldman, and our own J. Gordon Holt seemed only too happy to be rid of tubesmuch like repressed librarians celebrating the coming of computerized catalogs by torching their old card catalogs. (Yes, this happened. Bonfire celebrations.) If it hadn't been for Bill and Lew and a handful of others, including William Z. Johnson, of Audio Research Corporation, the tube renaissance that we enjoy today would never have taken place. Were it not for guitar-amp enthusiasts, tubes themselves would likely have gone out of production. Still, if you own tubed gear, you have Bill and Lew to thank, in part.
In 1981, two years before I joined Stereophile, I bought my first C-J component: a PV2 preamp. I forget what I paid, but it was around $700less than a tenth the price of the CT5. But figure in inflation and the PV2's price roughly triples. Then consider how far Conrad-Johnson has come.
Bill and Lew are in a tough business for anyone, let alone a pair of defrocked economists. Here's the problem: At this level of performance, any compromise you makeand you do have to make someis likely to be audible, impossible to cover up or correct for.
In this context, correct reminds me of the phrase department of corrections, as in prisons. (A better word is penitentiary; it conjures up sin.) Take the lid off some (most) solid-state gear and behold the corrections. That's what all those parts seem to be for: to put right what got wrong in the first place. You just keep correcting, then correct some more. Hard to stop. Yeah, right, you might get the gear to measure perfectlybut if two wrongs don't make a right, 30 or 40 wrongs most certainly won't. (JA will never print this.) As Bill Conrad put it, "You cannot fix what is screwed up before."
Preamps can be especially harmful, dragging an entire system down to a low level of performance. But this is also true of source componentsand, of course, recordings. It's rare when the stars align. But they will never align if your preamp is all wrong in the first place.
The easy way to build a preamp is to correct all over the place. Fine, if what you want to do is measure it instead of listen to music. The hard way is to design a preamp that needs noor few"corrections" in the first place. A preamp should possess puritycall it innocence. It should not come with a rap sheet.
The CT5 is a line-stage preamp with five line-level inputs. Its purpose is to step out of the way and let other components, especially source components, strut their stuff. And you pay $8500 for this?
Unfortunately, yes. All too often, a preamp intrudes itself in most unwelcome and even sinister ways. (Sinister in that an experienced listener knows there's something wrong but can't quite identify it.) A run-of-the-mill preamp is like an unfortunate cat with bad body odor: you cannot love the beast.
The CT in CT5 stands for composite triode. The entire (pre)amplification circuit is reduced to a single active stage, with no buffers or feedback. This is accomplished by paralleling the four sections of each of the two 6N30P twin-triode tubes, one per channel (WP explains in Vol.29 No.7).
One key to great preamp design is to isolate the audio signal from the radio frequency interference (RFI) that comes in over the power line. The CT5's discrete voltage regulator is designed to completely isolate the audio signal. Even so, C-J supplies a "hospital-grade" power cord. Why this should make a difference seems to frazzle some folks.
A proper power cord seems to stop most RFI from coming inor going out and messing up the sound of your other components. With the CT5, at least you won't have to invest several hundred dollars in an aftermarket AC cord from one of the wire bandits.
All control functions of the CT5 operate through microprocessor-controlled relays. To set the volume level and adjust the balance, the relays choose combinations from a network of precision, low-noise, metal-foil Vishay resistors.
Other expensive parts include the same Teflon capacitors found in the ACT2, used in the CT5 for output coupling and post-regulator power-supply storage. All other capacitors in the CT5's audio circuits and power supplies are polypropylene or polystyrene. The sealed-relay switches have gold-plated silver contacts.
Said Bill Conrad, "You listen long enough to figure out what's getting in the way and then you try to get rid of it. Every part, every piece, gets in the way a little bit. There is no such thing as a neutral part. We have things down to as simple a circuit as we can. When you do that, you had better use the best parts you can because there is no way to 'fix' it. But, of course, 'fixing' it never works.
"The Teflon capacitors that we use have less memory than anything else. Their ability to re-create ambience functions very well as an overall indicator of sound quality. Ambience retrieval means you also get the attack and decay of the notes. The Vishay resistors offer resolution, access, and detail. I would much prefer to find a way to build the CT5 cheaply, but I can't."
I have an inexpensive Chinese-made preamp in-house for direct comparisonbut it's too depressing to review when there's a CT5 sitting right next to it.
I won't give you the tedious audiophile song-and-dance about how I noticed this or that in a particular recording for the very first time. I listen for the whole, not the pieces.
Bill Conrad plays violin, so he brings to the table an amateur musician's perspective. He doesn't talk like an audiophile because, I suspect, he doesn't listen like one. "It's not so much about whether the hi-fi equipment puts you on edge, but rather that it doesn't let you relax into the music."
You can't do that if you're busy scribbling notes.
"Never mind, does it have highs, lows, middle, detail. Does it have music? Does the equipment capture the life of the performance, assuming it got grabbed on the recording in the first place?"
Bill talks about how, through a good audio component, pieces of a performance seem to fall into place so they are no longer pieces, but the whole. All too often, the opposite happens. He told me about a certain violinist whom he recently heard live. The orchestra and conductor were marvelously on song, setting the stage just right for the entrance of the violin. Which turned out all wrong, in musical but not technical termsin part, perhaps, because the violinist wasn't listening to the conductor and orchestra, but was in his own world. Yet technically, Bill said, the violin playing was perfect. Hi-fi can be like that: perfect in terms of test-bench measurements, but soulless, even clueless, in terms of re-creating the musical experience.
"Time-coherence information seems especially fragile," Bill continued. "We have developed our [human] hearing over the millennia, picking up on many clues for survival. They say a blind person going into a room can often describe the space of the room from the sound of the air."
This was good timing. Conrad-Johnson's CT5 and their ET250S power amp arrived just as John Quick, of Verity Audio, was setting up the Parsifal Encore loudspeakers, which are of impeccable quality (you just can't pec them). For a CD source, I used a Musical Fidelity X-RayV8 CD player as a CD transport into a Musical Fidelity Tri-Vista D/A converter (still one of my faves).
The CT5 had a way of filling out, of fleshing out the music, of imparting richness and body to the proceedings, of making performances seem less harmonically threadbare. This was true even with less-than-stellar recordings, and especially true with great historical performances.
The CT5 also worked to enhance both micro- and macrodynamics: those subtle and not-so-subtle dynamic shadings. Like the great line stage it is, the CT5 let the music live and breathe, enhancing and expanding rather than constraining.Sam Tellig