Floor Loudspeaker Reviews

Sources were, on phono, the now-familiar SOTA Star Sapphire with SME IV and AudioQuest 7000 running into the VTL Ultimate preamplifier. CD came from both the CAL Tempest II and the Stax DAC-X1t digital processor driven by a JVC XL-Z1010 player's digital output; this latter setup delivers the most musical sound from CD I've ever heard. It's the first CD source that's made me wish some of my LPs were on CD—though extended listening to even this setup revealed greater intimacy from LP. Still, I was impressed. The CS5s are very evenhanded, showing no strong preference for either LP or CD, though the less detailed and less involving sound from the CAL Tempest II CD player consistently lost out to LP before I switched to the Stax/JVC.

The most disappointing CS5 news, after you've had to give up on them because your room is too small, is that you'll probably want/need to buy a new amplifier. Though the CS5 doesn't discriminate against amplifiers the way the IRS Beta does (if you remember from my article in Vol.12 No.12, I found that only VTL 300W and 500W amplifiers worked well on the upper sections of the Betas, other excellent amplifiers being simply unpleasant), I found several very good amplifiers wanting.

The best one I heard was the Krell KSA-250 (their latest product—though by the time you read this there will be a KMA-600), followed not too far in second place by the older Krell KSA-200. The newly arrived Threshold SA/12 monos had plenty of overall power, but lacked the drive at the low end possessed in such quantity by both Krells, and had a refined, neutral upper range that seemed to leave the Thiels lacking in sparkle. Until now, my favorite overall amplifier has been the Mark Levinson No.20.5, but it simply didn't have the low-end punch necessary to bring the CS5 to life, and its "forgiving" upper range seemed to leave the speakers asleep.

The Manley 500s, which I held off hooking up for a long time, were, as nearly as I could determine, simply unable to deal with the CS5's cruel 2 ohm impedance at the low end. (David Manley, when told of my experience with the CS5s, informed me that the 500s could be restrapped for 1- or 2-ohm operation, still supplying their standard 500W, although with one quarter the voltage swing, of course. I question whether even this would suffice, however; I felt that even the thousand or so watts available from the KSA-250 at 2 ohms could have been improved on with two of them! No doubt this will inspire David Manley to design an even larger tube amplifier—the man generates new designs with the speed that insects display in modifying their genes.)

My previous auditions of the Manley 500, on speakers as diverse as the Mirage M-1 and the IRS Beta, had led me to think of it as the tube equivalent of the Levinson 20.5—an amplifier that allows any speaker to give of its best. Not with the CS5; in addition to a somewhat over-full mid- and upper bass, the mid-treble of the 500 sounded unpleasantly hashy, almost like a mildly mistracking cartridge (the sound was similar, however, on both LP and CD). Don't take it as a condemnation of this superb tube amplifier, though; it just won't work into this impedance strapped as it normally comes from the factory.

I don't quite know what to make of what seems to be this pretty severe amplifier sensitivity. Thiel certainly doesn't want to be known as a company whose products only work with Krells (as Apogee once was), vacuum tubes (as Infinity still is with their IRS line), Thresholds (the amp used in CS5 development), or Levinsons. In fact, prior to the CS5, Thiel was one of those companies recommending their products for use with "any excellent amplifier." Nor do I believe that the product simply "ruthlessly" reveals that which precedes it in the component chain. The amplifiers I tried and found at least somewhat lacking are truly excellent products, ones which will find very happy homes in other systems.—Larry Archibald