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.
Conclusion
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.
Finding matching powercables and interlinks
As always, matching cables to individual components is very important. In this case once again this is proven. For example the Coherence II already sounds very full and relaxed. Adding a Harmonic Technology Pro ACII powercable made it sound extra seductive but also slightly slower. Swapping for the Cardas Golden Reference tightened up the bass and brought more speed. The same applies to 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 little change brings this preamp closer to the sound of the Coherence II and the Synergy 2i. With interlinks it’s pretty much the same story: The Transparent Reference for example is a very full and royal sounding interlink that may be too much for the Synergy 2i but is fine with the Coherence II, and obligatory with the Synergy 1.
Digital Front End:
CEC TL1x CD Transport
Audiomeca Enkianthus X DAC
Power Amplifiers:
Jeff Rowland model 6 monos
Cables:
Transparent Ultra XLR (between DAC and preamp)
Transparent Reference XLR (between preamp and poweramps)
Transparent Reference XL speaker cable
Harmonic Technology Pro ACII powercable
Cardas Golden Reference powercable
Speakers:
B&W Nautilus 804
Goedenavond Christiaan,
Bedankt voor je uitleg en delen van kennis.
Toch nog twee vraagjes:
1. Is er klankmatig ( dus echt hoorbaar) verschil tussen de coherence 2 en de coherence 2 series 2.
2. Is de coherence 2 series 2 technisch ook beter, dus bv. ook minder storingen of onderdelen die minder vaak kapot gaan. Kortom betrouwbaarder.
Alvast bedankt.
Met vriendelijke groet,
Tim
I have not owned or heard a Coherence II series 1 and so have no comparison material. Judging from experience with other JRDG components that received updates though I’d say that the difference is definitely audible. In those cases the latest version has always been the most refined. Regarding reliability: I don’t think that one would be any more or less reliable than the other. Nothing in my past experience with JRDG products would indicate so. All JRDG products I owned have proven to be utterly reliable, apart from the Model 10 which had a problem with a batch of the supplied switching power supply components.
Dear Christian,
May i ask you for your recommendation on power cords for JR Coherence II and Cadence? With which cable did you made good results in your or in other well known systems?
Unfortunatelly, the reports and reviews are older, and in the meantime you have already other power cords in use, too.
Thanks and best regards
Balazs
Hi Balazs, although the Cadence is normally DC coupled to the Coherence, if you are referring to it using its standalone power supply then I’d say use Belden for best attack and transient sharpness or Furutech Alpha3 if you want a little more body and colour. The latter is currently being phased out so get it while you still can. For the Coherence II I found that two cables worked best: Cardas Clear Beyond (better for bass body and midrange tonality) or Fusion Audio Romance (better for fluidity, air and subtlety). Also see THIS REVIEW in which I compare old and new Rowland preamps and also use an aftermarket power supply for the Syngery.
Hi Christiaan,
I have a Coherence II preamp, I like it very much, but not long ago, when replacing the internal battery, the power supply parts were accidentally shorted and burned! I am very sad and regret!
However, now I have a chance to buy second-hand Synergy. Since both Synergy and Coherence’s power supply are compatible with Cadence, I assume that Synergy and Coherence’s power supply are also compatible.
Could you please advise if I can use Synergy’s power supply to connect to Coherence II. If feasible, I will buy Synergy and exchange the power supply to connect Synergy and Coherence to listen to these two preamps.
Thanks and Best Regards
Stanley
Hi Stanley, the Synergy’s power supply is actually the weakest point of the Synergy. The Synergy 2i has always been more refined than the Coherence II, even in a comparison after the latter was fitted with new batteries. However, the CII has always been more ballsy, more impactful and more sonorous.
I once connected the Coherence II’s power supply to the Synergy and that made a big difference, in favor of the Synery, once again indicating that it is a great preamp, hampered by its power supply.
After the Synergy IIi was fit with a BPS2 and huge switch-mode charger, this really turned the tables around and now the Synergy IIi was beating the CII in terms of pace, rhythm and dynamic slam. That, and it was more refined. So, even if you could probably make it work, I would not use a Synergy PS to power a Coherence II.
Why not take the CII to a trustworthy repair shop and have the components replaced? It should not be a hard fix.
Hi Christiaan, Thank you very much for your response. Yes, I took the CII to the repair center. After the inspection, they told that not only the charging circuit was burnt out, but also the control circuit on the front panel was broken, and the control circuit board had no parts!
BPS2 is quite rare in the market, I will want to buy it if I can find it.
Thanks and Best regards
Stanley
Ouch! Sorry to hear that. You could also consider building your own power supply. I mean, it does not need to be a battery buffered one. Charging aside, the supply is not at all complicated, and although I don’t have the voltages and connector pinouts at hand, I’m sure Jeff would be willing to share the required info with you.
Hallo Christiaan,
Leuk dat je zoveel over Jeff Rowland hebt geschreven.
Ik ben de blije eigenaar van een Coherence II (Serie 1) – ook nog in het deftige zwart. Het toeval wil dat ik vorig jaar ook een paar weken een 2e Coherence II, Serie 2, in mijn set (verder met Audio Research V70 en Genesis V luidsprekers) heb mogen beluisteren . Na vervanging van de accu’s in beide versterkers was er eigenlijk geen verschil meer hoorbaar tussen de Series 1 en 2.
(Het uiteindelijke karakter van de Coherence II wordt grotendeels bepaald door de Jensen in – en uitgangs transformatoren en die zijn hetzelfde)
Daarvoor klonk de Serie 1 wat “voller”, kennelijk door toedoen van de aanwezige recentere accu’s. Vervanging van de accu’s in beide versterkers was echt een grote verbetering, alsof de versterkers “wakker” waren geworden, nos steeds “smooth”, maar veel meer bij de les !
Wat wisselingen met andere voorversterkers brachten wel verandering in het geluid maar voor mij geen verbetering. Het karakter van de Coherence II : body, bass, souplesse, muzikaliteit en de juiste mix tussen detail / resolutie en smoothness, maakt dat ik (voorlopig) niet de behoefte heb om weer verder te gaan / te veranderen.
De match met de Genesis V (met enigszins uitgesproken middengebied) is zeer goed. Ook over de Genesis V is veel te schrijven (ga ik niet doen) maar het is een zeer goede allrounder met een ongekende laagweergave door het servo systeem van mr. Arnie Nudell / Paul mc Gowan.
Mijn vraag ligt in een advies voor een andere eindversterker. De V-70 is zeker niet slecht, maar ik heb de wens om ook een set Thiel CS6 te kunnen aansturen Dit gaat niet optimaal met de V-70. Eigenlijk zit ik aan een goede gebruikte (klasse A) eindtrap te denken, in de prijsklasse van rond de 3-4 duizend euro. Tot nu toe heeft klasse D me niet kunnen bekoren. Een oudere Jeff Rowland stereo eindtrap of mono-blokken is misschien wel te veel “smoothness” in de setup…. Ben benieuwd of jij er wat gedachten over hebt ……. ?
Hoi Ramon, dank voor je uiteenzetting. WBT de Genesis V luidsprekers zou ik een stevige transistorversterker adviseren. Een Rowland model 2 of model 6 zou kunnen en die zijn zeker niet te smooth. Dat heb je wel met bv de model 10 of 112. Als je vanaf buis komt zou ik ook geen klasse-D adviseren, niet dat dat niet ook goed kan zijn maar het is een hele andere sound. Desalniettemin zou je mss eens kunnen luisteren naar de NuPrime AMG STA (hybride klasse-A/D). Deze versterker heeft mij enorm verbaasd. Hij stuurt zelfs probleemloos Magico Q5’s aan. Klinkt ook meer als een ontzettend goede klasse A/B dan een klasse D en kost erg weinig. Zie ook mijn review op deze site. Ik kan me voorstellen dat je aanneemt dat een transistor klasse A dichter bij de V70 sound zit dan klasse A/B maar dat hoeft geenszins het geval te zijn. Veel klasse-A transistor versterkers hebben een soort stroperigheid die je met goede buizen juist niet hebt. Maar als je toch voor klasse A wilt gaan, wat ik wel mooi vind is een Accuphase A45 of A47.