Jeff Rowland Coherence II compared to Synergy 1 and Synergy 2i
Coherence II: the legend compared to its offspring
Nothing was left to chance for this exiting review
All preamps were fully run in and warmed up and all continuously powered up simultaneously. When comparing individual preamps I used the same power cable in the same wall outlet and placed the preamps in the exact same physical position as the previous one was. So when done with one preamp, it was disconnected, moved it away and connected to a temporary powersource to keep it warm. Then the next preamp was moved into the position of the previous preamp, connected with the same cables.
Starting with the Coherence II
The Coherence II preamp sounds extremely smooth, fluid and relaxed, with a very sonorous, full bass. while still maintaining focus and offering ultra-fine low level detail. It is like listening to a typical tube preamp, a Jadis JP80 for example, but with much higher resolution, way airier and nuanced treble and much better low level detailing. The soundstage is very wide and deep and all the instruments have their own spaces with lots of air around them.
Because this preamp is so relaxed and natural it emphasizes nothing and also doesn’t add artificial speed or edge. There is just none of the transient overshoot that makes some audio components sound extra “exciting” or forward. In some setups therefore the Coherence II (as well as the Synergy 2i) may be too much of a good thing when just dropped in as replacement without making adjustments are made elsewhere in the system.
When playing from pure battery power (switching to DC mode disconnects the AC charger) the Coherence II sounds even more fluid and comes across as more generous, with an even more real sounding midrange. The bass in DC mode does however lose a little attack and transient sharpness. It’s up to the user to decide which mode sounds best. The good thing is that it is switchable and can be changed on demand, for example on those cold winter nights, or with a hard sounding source, DC might be just what the doctor ordered. For me, AC sounds best the majority of the time. Surprisingly, it still matters what kind of powercord is attached, even when playing from battery. For example a warm sounding cable still makes the Coherence II sounds warmer. All further comments regarding the Coherence II are made with the BPS on AC mode (running off batteries but with the charger switched on).
Moving to the Synergy 2i
The Synergy 2i sounds a lot like the Coherence II but misses the mark in two important areas: midband tonality and liveliness and bass power. The Synergy 2i is even more creamy and relaxed and is decidedly less sonorous and more woolly in the bass. It also has quite a less powerful sound, especially lacking body in the bass and can therefore be more demanding of the setup in which it is placed.
But in the right company and properly tuned, the Synergy 2i can also be extremely rewarding, having a similar suptuous, superwide soundstage and even more fluid and airy highs, although this particular difference is negligible when running on DC mode. The Synergy IIi’s circuitry may be derived from the Coherence’s, but the latter has a much beefier power supply, and of course the BPS, and this seems to make all the difference.
Moving to the Synergy 1
Because this is currently my own preamp, I feared that it would be totally eclipsed by the other two preamps but it wasn’t all bad. Not at all. Indeed, the Synergy 1 has less airy treble than the Coherence II and it isn’t as fluid or full-bodied and generous soundstage-wise as the Coherence II and Synergy 2i.
But there are departments in which the Synergy 1 is better than the Synergy 2i, and even better than the Coherence II: The bass! Its bass is very quick and agile, it really snaps and drives the music along with great PRAT. It’s easily got the best-textured bass of the three preamps. It’s also the quickest, most agile sounding preamp of the three.
Somehow however the Synergy 1 doesn’t sound as lyrical as either the Coherence II or the Synergy 2i, in spite of its excellent dynamic and rhythmic qualities.
When the Coherence II was introduced, it caused quite a stir. And I can report that it still sounds incredible. It combines the strengths of both Synergy 1 and Synergy 2i to make for a very relaxed sound, that’s at the same time rhythmic and dynamic and extremely finely detailed, with big bass as a bonus. It easily matches the best tube preamps I have heard so far in terms of midrange fluidity and I really feel that it betters them in terms of airiness, spaciousness and microdetailing. I want one. Too bad they are scarce and the owner of this model isn’t about to sell.
Then there’s the Synergy 2i. There is a lot of Coherence II in this amp. For example: the royal, fluid soundstage that really envelops you like a warm bath. It has that. Almost as good as the Coherence. Its treble is even airier and refined than that of the Coherence II. But where it lets down is in the bass department. Its bass is very finely detailed but it is quite loose and lacks body and dynamic expression. You really need to match this amp with the appropriate interlinks and powercables as well as provide a quick and dynamic sytem for it to play in. Then, is everything is right, it will really reward with a captivatingly romantic sound.
The Synergy 1 is a bit of a different animal. It easily betters both the Coherence and Synergy 2i in terms of bass. It is very fast, agile, clean and dynamic. But it is a Rowland, so it is also fluid, relaxed and musical. It also has a very large soundstage, almost as good as the Synergy 2i. Its treble is more resolute and slightly darker than either Synergy 2i or Coherence II. Mind you, it is still airy and refined, just less so than the other two.