JEFF ROWLAND SYNERGY 1, SYNERGY 2i AND COHERENCE II
The legend compared to its offspring
Starting with the Coherence II
The Coherence preamp sounds extremely smooth, fluid and relaxed, while still maintaining focus and offering ultrafine low level detail. It is like listening to the quintessial tube preamp, a Jadis JP80 for example, but with much higher resolution, way airier highs and much better low level detailling. The soundstage is very wide and deep and all instruments have their own spaces and have lots of air around them. The only aspect about its sound that could potentially become a problem is the tightness and attack. Because this preamp is so relaxed and natural it emphasizes nothing and also doesn't add artificial speed or edge. In some setups therefore the Coherence (and the Synergy 2i alike) may be too much of a good thing and further changes to the system may be necessary.
When playing from battery power its sound gets even more fluid and it comes across as more generous and even more real. The bass loses a little attack, but that's a tiny sacrifice that's absolutely worth it. Surprisingly, it still matters what kind of powercord is attached, even when playing from battery. For example a warm cable still sounds warm. All further comments regarding the Coherence II are made with the BPS (battery power supply) switched on.
Moving to the Synergy 2i
The Synergy 2i sounds a lot like the Coherence II but misses the mark most in 2 areas: midband livelyness and bass. The Synergy 2i is even more demanding of setup as the Coherence II is because its even more relaxed and has even less bass attack and tightness. But in the right company and properly tuned, the Synergy 2i can also be extremely rewarding, having almost the same kind of suptuous, superwide soundstage with the same fluid highs. Probably the Coherence is better in these respects because of its bigger power supply. The rest of the circuit is broadly the same.
Moving to the Synergy 1
Because this is currently my own preamp, I feared that it would be totally eclipsed by the preceding preamps but it wasn't all bad. Not at all. Indeed, the Synergy 1 isn't as fluid, nor is it as generous and sumptuous soundstage-wise as the Coherence, or even the Synergy 2i. The highs are even a little less fluid and open, but still good. But there are departments in which the Synergy 1 is clearly 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. It's easily got the best-textured bass of the three preamps. It's also the quickest preamp. This is probably so because the Synergy 1 only has input transformers whereas both the Synergy 2i and the Coherence II have input- and output transformers. Transformers always tend to slightly round off the sound and in the case of these preamps, practice seems to correlate with this.
The Coherence II is a legendary preamp. At its introduction nothing could touch it. So how does it compare now? To make it more interesting we assembled its later brethren the Synergy 1 and 2i to see how much quality has been passed genetically...
Nothing was left to chance for this exiting review:
All preamps were fully warmed up, run in and all powered up simultaneously. When comparing them we used the same power cable in the same wall outlet and placed the preamps in the exact same position as the previous one was. So when done with one preamp, we moved disconnected it, moved it away, connected it to a temporary powersource to keep it warm and moved the next preamp into the position of the previous preamp and connected it with the same cables.
From left to right: Synergy 2i, Coherence II, Synergy 1
Inside are pretty similar electronics. The Coherence II was produced first and it is the oldest of the three. It was the flagship preamp of the time, and it still counts amongst the best currently available. It has both input- and output transformers and is made from milled solid aluminum. Both parts of the preamp weigh 20kilos, making for a total of 40kilos!
Next came the more affordable, sort of spin-off Synergy 1. It has similar electronics, but simpler, and also it only had input transformers.
After that came the Synergy 2 and later the upgrade 2i. These electronics were really very much like that in the Coherence, including both input- and output transformers. The sound of the synergy 2i is pretty close to that of the Coherence. But not quite the same.
Synergy 1 and 2(i) are virtually indistinguisable, but Synergy 1 is recognisable by its red display. Underneath are Universal Ceraballs
Synergy 2i, recognisable by a green or blue display and extra outputs at the back
Coherence series II
A word about matching powercables and interlinks
As always, matching cables to components is very important. In this case again this is proven.
For example the Coherence already is very full and relaxed. Adding a Harmonic Pro ACII powercable made it extra seductive but also slightly slower. Swapping for the Cardas Golden Reference tightened up the bas and brought more speed. The same goes for the Synergy 2i, which is even more relaxed than the Coherence II. But the Synergy 1 is very fast, open and agile. This amp can really put the Harmonic Pro ACII to good use. This brings him closer to the sound of the Coherence II and the Synergy 2i.
With interlinks it's pretty much the same story: The Transparent Reference is a very full and royal sounding interlink that may be too much for the Synergy 2i but it is fine with the Coherence II. And it is obligatory with the Synergy 1.
When the Coherence II was introduced, it caused quite a stir. And I can report that it still does. It retro-combines the strengts of both Synergy 1 and Synergy 2i t make for a very relaxed sound, that's at the same time rhythmic and dynamic and extremely finely detailed. It easily matches the best tube preamps I have heard for midrange and fluidness but I really think it even betters them for 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 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 highs are also almost a match. But where it lets down is in the bass department. Its bass is well-textured and finely detailed but it is quite loose and lacks a bit of dynamics. 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 reward with an almost-Coherence II sound.
The Synergy 1 is a bit of a different animal. It easily betters both the Coherence and Synergy 2i for 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. Where it deviates as well is in the high frequencies. It 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.