Jeff Rowland Design Group Synergy line preamplifier:
Page 3 Instruments and voices were defined in space with great precision, the VK-5i—which I had not thought of as being weak in this department—sounding very slightly veiled in comparison. This was particularly impressive with transients, such as the varied percussive sounds of All Star Percussion (Golden String GS CD 005). The Synergy also had deeper, better-controlled bass, evident with plucked string bass and bass drums.

Although the Synergy's clarity, bass response, soundstaging precision, and detail were ahead of the VK-5i's, I found the latter to be superior in its ability to present instrumental and vocal textures in a natural, harmonically accurate manner. The Synergy certainly doesn't have the kind of overly etched sound that many people associate with solid-state; it evinces no harshness or stridency other than what is obviously source-related.

And yet...with the VK-5i, "Valse Frontenac" on Beauty of the North had a more relaxed, less "sharp" sound, the accordion having more of the bittersweet quality characteristic of the real instrument rather than an electronic reproduction thereof. With the VK-5i, Sylvia McNair (Sure Thing: The Jerome Kern Songbook, Philips 442 129-2) was more plausibly present in the room, even though the Synergy allowed me to focus more easily on details of voice production and the technology of the recording itself (like an apparent edit at 1:32 of track 10).

Once the source gain had been increased by 8 or 9dB, the Synergy did a good job of presenting the music's dynamics and rhythmic qualities, but the BAT VK-5i and the CAT SL-1 Signature Mk.II were better still, communicating more of a sense of the music's ebb and flow.

These observations refer to each preamplifier being combined with the Rowland Model 2 amplifier, a pairing that in the Synergy's case might be expected to be particularly...well...synergistic. The Synergy/Model 2 combination was certainly an effective one: squeaky-clean and highly detailed. For my taste, it was almost too clean, too detailed, in a way that occasionally called attention to the technology rather than the music.

Overall, I preferred the Synergy when it was driving the Sonic Frontiers Power 2. Another fully balanced design, the Power 2 is almost entirely free of "tubey" colorations, although it still doesn't sound like a solid-state amplifier. (If it did, why would Sonic Frontiers bother making it?) Combining the taut precision of the Synergy with the Power 2's more liquid presentation seemed to bring out the best in each component: a nice balance of solid-state and tube virtues. Compared to the two tube preamps, there was still a trace of an "electronic" quality to the sound, but it came down to the perennial question: Do tube preamps sweeten the sound, thereby being technically less accurate if musically more pleasing, or was the Synergy introducing a subtle form of distortion that, although low in absolute level, was musically discordant? Tough question, but I'll stick my neck out and say that I think it's more the latter.

Initial conclusion
Beautifully made, featuring considerable control flexibility and a useful remote, the Jeff Rowland Design Group Synergy stood up well to comparison with the reference BAT VK-5i, scoring points in clarity, bass quality/extension, low-level resolution, and the precision of images within the soundstage. Ultimately, my preference is still with tube preamps like the BAT and the CAT SL-1 Signature Mk.II, which offer what strike me as a more natural rendering of harmonics and superior dynamics. At the levels of performance represented by the preamps from Rowland, BAT, and CAT, system matching and personal preference are paramount. Anyone considering preamps in this price range should certainly include the Synergy on their short list. It's not the preamp for me, but it might well be the preamp for you.

Postscript
Stereophile's review policy is that, minor tweaks aside, products are to be evaluated in stock form; using a power supply borrowed from a different product would seem to go well beyond the definition of a "minor tweak." However, with the review proper concluded, I wondered what the Synergy would sound like with the Coherence preamp's battery-based power supply, which is electrically and plug-compatible with the Synergy. When a friend offered to let me try the power supply of his Coherence, it was an offer I couldn't refuse. (Thanks, Bruce!) By this time, the speakers in the system were Hales Revelation Threes.

What a difference! More dynamic, more transparent, and an overall presentation that just sounds more natural, less "electronic." The degree of improvement was much greater than I had found between the Rowland Model 2 amplifier in the AC- vs DC-powered mode. I can only conclude that the limiting factor in the Synergy's performance appears to be its power supply (footnote 2). In checking with Rowland, I was informed that they now offer an optional battery power supply for the Synergy. The BPS-1 is identical to the Coherence power supply in every respect except cosmetics, which are designed to match the Synergy's.

Alas, the BPS-1 costs $3400, and you still need to retain the standard Synergy power-supply unit for volume display and remote-control operation. Is the difference worth it? That depends very much on your finances and priorities. All I can say is that, for me, the addition of the BPS-1 transforms the Synergy from a preamp that I respect and admire but that overall isn't my cuppa, to one that I could be very happy with and recommend without reservation.

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Footnote 2: Unlike the Synergy's own power supply, the Coherence power supply was not stacked with the preamp proper, which made me wonder if it was just the physical separation of power supply and preamp that was responsible for the improvement. I listened again to the Synergy power-supply/preamp combination with the power supply separated and placed on the same Sumiko Navcom Silencer supports I'd used under the Coherence power supply. Results: no difference that I could hear.—Robert Deutsch