LPs. Oh, dear. I've just received the latest issue of the Schwann Opus, and I see that it no longer lists LPs (footnote 3). When I requested PAC to send me a review sample of the phono-staged CPR, I was told that they'd have to build me one: there's so little demand for it that all they keep in stock is the line-stage–only model!
As it turned out, the performance of the phono stage was a bit of a disappointment after the excellence of the line stage. The first problem was minor and idiosyncratic: in the "Recharge" position, there was a loud hum that defied all my efforts to get rid of it. I tried the usual solutions—grounding/ungrounding the turntable and the preamp, reversing the orientation of AC plugs—but to no avail. This problem is very likely due to some sort of ground loop in my system; in any case, putting the TIPS in "Total Isolation" mode eliminates it.
Somewhat more problematic is the noise that remains even in the "Total Isolation" mode: broadband noise that's noticeable during quiet passages, with music being played at not-unreasonable levels (listening-seat peaks around 90dB, Radio Shack SPL meter, "C" weighting, "fast" response). To be fair, the only preamp I've encountered that's able to handle the AQ 7000 without some audible noise is the Mark Levinson No.28, but, given its dead-quiet line stage, I expected the CPR/TIPS to do better.
Apart from the noise, the CPR's phono stage had much the same easy-on-the-ear quality as its line stage, but with a relatively lower level of transparency. (The latter could, of course, be a function of the noise level.) It may well be that the AQ 7000 is not the ideal match with the CPR; a higher-output moving-coil would likely be a better choice.
My last comparison was the dreaded bypass test, using the Stax Lambda Signature/SRM-T1 combo, comparing the sound of the signal that has gone through the line stage with the signal being fed more or less directly from the D/A processor (actually, from the tape-output jack, so that the possible effects of an additional cable and RCA jack are controlled). Every preamp I've put through this test has shown some degradation of the signal; the CPR/TIPS was no exception. The relatively direct sound had more of a see-through quality, with a better sense of space, and less grain. Having said that, I must point out that the magnitude of the difference was quite small—smaller than the difference between the sound of the line stage in the "Recharge" and the "Total Isolation" modes—and that no preamp I've tested has done better on this test.
Some practical concerns
Battery operation may have its advantages (see sidebar), but, as with most other things in audio, there's a potential downside. First, there's the matter of battery life. This is not as bad as one might expect. The CPR/TIPS has a five-year transferable warranty that includes the LCR batteries, which are said to have an expected life of about eight years. PAC estimates that complete battery replacement in five years' time would cost about $200. LCR batteries are available from several sources (PAC gets theirs from Panasonic), so it's not like using vacuum tubes made only in Ulan Bator.
A more immediate concern has to do with battery recharging. Although the preamp can be listened to in the "Total Isolation" mode for extended periods of time (I had it on for nearly two days before the LEDs went out), you do have to keep track of how long you've had it in this mode; the factory recommendation is that the recharge time should equal or exceed the isolated time. (But remember: unlike NiCads, LCR batteries don't develop a "memory" if they're recharged before being completely discharged.) If you have even a slight tendency to compulsiveness—and what audiophile doesn't?—you'll find yourself switching it off—ie, putting it in the "Recharge" mode—for a few hours during the day, then having to remember to flip the switch up when you're going to do any serious listening. The switch is so small and the mode-indicating LEDs are so obscure in their operation that you have to go right up to the preamp to tell which mode it's in. This is a pain. If the TIPS were to be revised, PAC might consider changing the LEDs and their control circuits so that the mode of operation is indicated by color—ie, red vs green—rather than by brightness.
Conclusion
By completely isolating the preamp's power supply from the AC line, Perfectionist Audio has provided an elegant solution to the vexing problem of AC line interference. Now, all that may be very well, but it would be of little import if the preamp did not sound good. The CPR/TIPS does! Although the bypass test shows that, like other preamps, the CPR/TIPS's line stage doesn't quite achieve the ideal of "straight wire with gain," its neutral tonal balance, soundstage depth and width, preservation of recorded ambience and the music's rhythmic quality, and, most important, its ability to provide musically relevant detail with a minimum of electronic artifacts, confirm that this is an outstanding preamp, and the unusual approach to power-supply design must take at least part of the credit. I have some reservations about the performance of the moving-coil stage (with my cartridge, it was a bit on the noisy side), and the use of batteries means that the CPR/TIPS is not a product that you can just plug in and forget. (Of course, neither are tube preamps.) The CPR/TIPS brings to seven the number of preamps I've listened to at some length during the past year. Because of changes in associated equipment, overall comparisons are likely to be misleading, but I can't help having favorites. One of these remains the Conrad-Johnson PV11, a preamp that may not be the most literally accurate in the world, but which doesn't have an amusical bone in its body. To anyone still bothered by the harshness of CDs, and who doesn't want to spend more than $2000 for a preamp, I recommend the PV11 (footnote 4). The Coda FET-01 and the revised version of the Rowland Consonance are both excellent, no-fuss/no-bother preamps, the Consonance with a versatile remote control that's in a class by itself for convenience.
Finally, the PAC CPR IIIb/TIPS (it is a mouthful!) strikes me as the most successful in providing the fine details of musical performance while avoiding the clinical, "ruthlessly revealing" tendency that "accuracy" normally implies.
Footnote 3: Interestingly, Spectrum, the Schwann Guide to nonclassical music, which is puboished by Stereophile, continues to list LPs; editor Jane Poirier Hart told me that they will continue to do so as long as LPs are available, even though their numbers are dwindling. Footnote 4: The other recommendation is, of course, to get a better CD player or D/A processor (like the PS Audio UltraLink).
Battery operation may have its advantages (see sidebar), but, as with most other things in audio, there's a potential downside. First, there's the matter of battery life. This is not as bad as one might expect. The CPR/TIPS has a five-year transferable warranty that includes the LCR batteries, which are said to have an expected life of about eight years. PAC estimates that complete battery replacement in five years' time would cost about $200. LCR batteries are available from several sources (PAC gets theirs from Panasonic), so it's not like using vacuum tubes made only in Ulan Bator.
By completely isolating the preamp's power supply from the AC line, Perfectionist Audio has provided an elegant solution to the vexing problem of AC line interference. Now, all that may be very well, but it would be of little import if the preamp did not sound good. The CPR/TIPS does! Although the bypass test shows that, like other preamps, the CPR/TIPS's line stage doesn't quite achieve the ideal of "straight wire with gain," its neutral tonal balance, soundstage depth and width, preservation of recorded ambience and the music's rhythmic quality, and, most important, its ability to provide musically relevant detail with a minimum of electronic artifacts, confirm that this is an outstanding preamp, and the unusual approach to power-supply design must take at least part of the credit. I have some reservations about the performance of the moving-coil stage (with my cartridge, it was a bit on the noisy side), and the use of batteries means that the CPR/TIPS is not a product that you can just plug in and forget. (Of course, neither are tube preamps.) The CPR/TIPS brings to seven the number of preamps I've listened to at some length during the past year. Because of changes in associated equipment, overall comparisons are likely to be misleading, but I can't help having favorites. One of these remains the Conrad-Johnson PV11, a preamp that may not be the most literally accurate in the world, but which doesn't have an amusical bone in its body. To anyone still bothered by the harshness of CDs, and who doesn't want to spend more than $2000 for a preamp, I recommend the PV11 (footnote 4). The Coda FET-01 and the revised version of the Rowland Consonance are both excellent, no-fuss/no-bother preamps, the Consonance with a versatile remote control that's in a class by itself for convenience.
Footnote 3: Interestingly, Spectrum, the Schwann Guide to nonclassical music, which is puboished by Stereophile, continues to list LPs; editor Jane Poirier Hart told me that they will continue to do so as long as LPs are available, even though their numbers are dwindling. Footnote 4: The other recommendation is, of course, to get a better CD player or D/A processor (like the PS Audio UltraLink).
