corus vs coherence 2

Hi am wondering if anyone has ever compared the Jeff Rowland pre amps and if so what are your thoughts.
Plataman, I am very familiar with Corus, as I own the Rowland Criterion, which shares very similar audio circuit and AC power supply. I have not experienced the Coherence series, but I am familiar with the general evolution of the Rowland sound over the last couple of decades.

Rowland has evolved over the last 25 years from an essentially warm sound with a slight golden glow and a moderate transparency, to a much more neutral sound that is however more revealing of inner detail without ever falling onto the analitical side.

So, it really depends on what kind of musicality you are seeking.... Romantic with a touch of pastel, or more lifelike and -- at least for me -- even more toe-tapping emotional.

One of the unique things that you would find with Corus is that it is almost insensitive to power cords. With its sibling Criterion, I have not experienced any performance difference among any power cords I fed it with: stock, Furutech Evo II and Flux, Shunyata King Cobra CX, Aural Symphonics.... Oh yes, these cords influence greatly a lot of components, but not Corus/Criterion.

Over the years I've owned a couple of Coherence IIs as well as all of the iterations of the Synergy (I, II, IIi). Right now I'm quite impatiently awaiting the arrival of a Corus.

Guido's description is pretty much spot on and the last iterations of the Coherence and Synergy were just on the warm side of neutral. I was always a big fan of the Coherence and ultimately let mine go as I needed a pre with a home theater bypass input which could be selected by remote control (so that I could fully automate the system in my old house).

This was back in early 2008 and I looked at a number of preamps which were current at the time. I really wanted a Criterion, but the product wasn't shipping yet. I ultimately went a completely different route and picked up a VTL TL-7.5 Series II. While this unit solved my ergonomic issues it also showed me that the Coherence was limiting dynamics somewhat. While the Coherence was fully capable of reproducing a dynamic signal my feeling was that its rise time was a bit slow which made the leading edge of transients sound a bit muddy.

Don't get me wrong, the Coherence was an excellent preamp in its day, but has since been surpassed by a number of designs. I can't tell you how the Corus compares as I haven't received mine yet, but based on numerous conversations with Corus / Criterion owners (Guido included) it sounds as if the overall presentation has much improved over the previous designs. Since I was getting ready to pull the trigger on a pair of M925s I decided to order the Corus as well with the hope of a synergistic match between amps and pre.

As much as I love the Coherence and have very fond memories of it I would look to newer designs in order to take advantage of 15 years of progress in circuit and power supply design.
This is a really good question, and can be generalized to a lot of different high-end manufacturers and their philosophy, technology, and marketing.
I have owned Rowland consonance and consummate preamps, and both sounded excellent and worked really well, with one of the best remote controls i have EVER seen. not content with these superb pieces, Jeff went on to create the synergy and the coherence-2, one with, and one without, battery power. now he has two preamps which AGAIN offer batteries or No, but similar designs.
in mentioning the Coherence Two, you bring up quite a mystery in that it had an outboard power supply with rechargeable battery packs. it was expensive and very elegant in design, but it got pulled from the market sort of early and without much explaination. some said it was too difficult to produce for the given price (although the price was not all that unusual for the time). perhaps there was a problem with getting the batteries to perform in an optimal way. plus you had to get new ones from JRDG, the only supplier
in the world for that particular design. BUT... the preamp had to be very very quiet indeed, with lots of room to separate noise-generating parts from other noise-sensitive ones, a specialty Jeff had a good reputation for knowing a great deal about. As for the Synergy and Synergy-2, they are balanced-only,
and are also highly regarded with outboard power supplies. must be pretty good, right? not as good as the newest pre's though.
with all of the water under the bridge, and as much as i respect this company (having owned preamps and amps made by them myself), what
IS the advantage of a Corus line stage on A/C power compared to a properly
running Coherence-2 on battery power? how obvious would this difference be? and is anyone going to conduct this comparison and report on it in a well-read journal?
Mark Levinson is coming out with a new $25,000 preamp as well, the #52,which should be "a bit" better than the 326S ($10,000), their current best line-stage. now the 326S is said to be DEAD QUIET with a huge stage, etc.
so what is the #52 going to do? dare i ask? i don't mean to be cynical here, and one picture of the huge two-box reference to come out shortly is very impressive (naturally), but when is the need to "upgrade" from a $10K pre to a $25K pre based purely on value and markedly superior sonics as opposed to
jerking audiophiles around yet again? is the day soon to come where the best line stages will all be over $20,000... $30,000...? Audio Research certainly is not waiting for the SOTA pricing question to go unanswered. 1st you have the Anniversary-40, and now the REF-10, which blows the tires off of the A-40 and the poor little 5SE. someone bring me a drink (of water that is...) everyone desires a really superb preamp to anchor their highly coherent sound system.
QUESTION IS, when is enough enough? when can we expect the VERY BEST POSSIBLE RECORDINGS to be released with clear labeling of what is inside, so we don't have to sit in front of our humongous speakers and be disappointed yet again at the fumbling/bumbling results of engineers focusing on the wrong objectives? even with all of the helpful suggestions/reviews about gear and room acoustics, there STILL is a lot of inferior source material out there. and for a few bucks more (or less) for the "right stuff" we can get light-years closer to realistic sound.
Very good points French_Fries. In the case of Rowland Corus/implementation with batteries -- under the name Criterion -- it was withdrawn about a year ago... It did sell for a 5K to 6K price premium over Corus. In my system, Criterion seems invariant to AC vs battery operation for all PCs that I have applied to it, hence it would have little advantage over Corus. On the other hand, I have listened to at least one system where Criterion on battery sounded very much cleaner than when it was served by AC... So, seems that the answer is, as always... It depends! G.
One interesting feature of Corus is that it is compatible with an upcoming external Rowland power supply based on supercapacitor technology to be called PSU. Yes, of course, PSU will add a fair chunk to the price of a Corus, but unlike the Criterion with its battery unit, PSU is completely optional and can power two devices at the same time (Corus and Aeris).

If my conjectures prove to be correct, PSU might further enhance authority and transient speed to Corus.... But until someone tries PSU out, my conjecture is only worth the electrons expended in displaying it.

Thank fully "supercapacitor" is not a new fangled nuveau-fizzy-marketing term.... it's a class of devices that combine quasi-battery energy density with quasi-capacitor charge/discharge cycling... Look them up on Wikipedia if interested.

thanks for the great discussion regarding REAL improvements in the sound of these components. BTW, i didn't know that the Criterion preamp had been discontinued....! wow, this IS a surprise. and the upgraded power supply for Corus is soon to be released- also, very interesting news indeed.
i guess i am getting a moldy brain when it comes to what these newer products can do for a more realistic presentation. i just tend to think of, for example, the Pass Aleph-P, which came out some time ago, a simple box running in Class-A, which sounded almost as good as a passive preamp in a stereophile test. i get "stuck" i suppose in thinking that at a certain point, you have a great preamp, so quit window shopping- in this case for an XP-30 ( or the rumored XS-series preamp to be releaseed). but i admit my personal biases- even though, as a Rowland audio-salesman told me as i took home my (1st big purchase) Consonance from his store , that "now you're done, that piece of your audio system is taken care of". i finally had a 1st rate, high-end component, built to an incredible standard, nothing like my mid-fi harman kardon preamp i had brought in on trade.
but i must now face a different challenge- WHICH high-end preamp gets out of the way of the music better than all of the other offerings at prices i can't afford anyway?
I kept worrying about how much money i had just spent- $3500 for (just) a preamp, and yet since that fateful day, I have had a Pass Aleph-P, a Consummate, and EMM lab pre/dac, a levinson 380S, and now a levinson 326S. and THAT is now quickly becoming passe... i think i need a big spoonful of Geritol and a nice long nap.
you youngsters better carry on without me....
Thanks for your responses, I appreciate them all. I has spoken to a technician who does authorised service for Rowland,Arc and a few other manufactures and he seems to think that the ARC Ref3 or Ref2 mk2 would in his words smoke the Coherence 2 but he couldn't comment about the Corus since he hadn't heard it. Feel free to comment and thanks again, you have been very helpful.
I owned Rowland gear in the 90's, then I made a long stop from 2001 until 2011 because none of those newer units moved me. In a way, power, but dead. I bought Coherence II.2 + Model 2 with Battery Power Supply 2012 and I think, they have indeed something to do with a musical reproduction.
Marketing will let us know that the latest is always the best. But you don't get a definition of "best". Instead you get a lot of technical explanations what parts are inside but you don't know what they do. A good Design is very often a combination of knowledge and pure luck. There is absolutely no guarantee that the next unit from the same designer will be better. Different of course, but better? There are endless examples out there, countless Audio Research units, Cartridges, Tonearms .... and so on. The old Pass Aleph amps beat any new in any second of the day when they are connected to a matching speaker. They can't drive ultra low loads, but is that a proof that they are worse?? Isn't it more intelligent to avoid such a Speaker Design and to look for something better....?

I listened to Criterion and I decided to go for Coherence II, but my priorities will not be shared from everyone. Most think, when they hear a difference, that this difference is better (for example, louder is always better, faster is always better.....) but a musical reproduction, the illusion of being part of a Performance is something different. Spectral for example is fast, but none of their units have something in common with music. It is the way it is.

Rowland gear is good, personally I don't like the Switch Mode Power Supplies, the sound is going on my nerves after a few hours, but there are others out there who like it more.
The Coherence II has a very unique internal Design with some very, very expensive parts and intelligent technical solutions. The XLR input and output are different from the "old" ones and the newer ones, so when you compare them you have to get the right cable terminations :-)
Specially when a Cadence Phono is used also (a very amazing unit, but wrong cable termination will rob a lot of its abilities...).
It is no secret that the very best sounding Rowland amps were Model 2/6/8/9.... some - intelligent - Dealers announced the 625 Model as the next best units after Model 8.... Marketing is one side, proof or time another....
Hi Syntax, Rowland seems to have passed through an inter-regnum at the end of the age of the single digit classics, when for a spell his soul seeking lead to some devices which fell just short of being emotional. Which amps and preamps did you experience as somewhat unemotional? G.
Let me throw another comment into this discussion since i have owned the Model-12 monoblocks. hey, remember the #10 and #12? doesn't come up much in discussions. after hearing Diane Krall through a #10 at the local dealer (whose main listening room is a marvel of great acoustics) i threw a large am't of money down on the 12's. they sounded absolutely great except they didn't like brown outs- which i have all the time. after going back to colorado twice Jeff assured me the ps's had been modified/replaced and would never give me any more problems.
by then i was kinda bummed out about the whole affair and got Levinson 33H amps which completely floored me- dynamics and musical and every nice adjective you can come up with. i still have the 12's as backup and can't decide whether to sell them or not. but they easily matched the Pass Aleph 1.2's (the biggest in that line) for smooth relaxed "tube sound without the tubes" presentation. without getting so hot.
but even if the 10 and 12 never got much attention. am i to understand that the newer products are going to make the 12's sound veiled or whatever...?
even with significant improvements i AM interested in the new pieces. BUT-
that day listening to Ms.Krall years ago was pretty amazing...thrilling. $14,400 for a pair of amps- WOW, i must have been pretty moved...
Hi Syntax, I fully understand your point as I myself have wrongly taken different for better and had to eat my words. Sometimes companies strive for improvement and mess up a good thing and that's the irony of this hobby.
French_Fries, it is my understanding that the group of products formed by M10, M12, M112, M302, and M301 up to serial 71, were all sweet sounding to the detriment of some emotionality at the micro and macro level.

the following generation of amps followed two diverging routes...

the higher end M312 stereo and later production M301 monos were much more emotional products than the previous 2 generations in the micro/macro domains, while the lower end products like M201 and M501 sounded somewhat matter-of-fact unless they were fed through the JRDG PC-1 rectifier. M301, M312, M201, and M501 are all withdrawn.

The current generation of amps is growing into a much broader family: M925, M825, M725, M625, M525, M125.

The early incarnation of the M625 stereo exhibited a denser harmonic content than M312 but in some cases sounded slightly less transparent. It is my understanding that the slight regression in transparency has been addressed by a minor internal change. The original M625 stereo in my system generated stage and images that were approximately 2/3 the size of M312... Driving the Vienna Muzik, it sometimes gave me impression of having to "work for living".... There was the slightest impression of the amp running out of steem on intense orchestral tutti.

M725 mono cleans up all the residual issues of M625... At least as transparent as M312, but with lots more harmonic content, equal or larger stage and images, authority galore, and oddly enough, greater control and musicality of the bass, in spite of it having lower damping factor than M312... Which points to the fact that published specs are not necessarily good predictors of product behavior. Oh yes, and apreciably better control of intermodulation in treble, which yields treble that is even sweeter than M312 without being dampened nor foreshortened. Bottomline: M725 replaced M312 as my reference because it is more resolving, more transparent, and more musical than M312.

M625 and M725 remain current products. The amp line is being augmented both upward and downward.... M925 monoblocks have been released in January and I have a pair on order. The M825 stereo will be released in April, together with a lower end M525 bridgeable amp, and an entry level M125 stereo. How will they sound? I do not know yet, and any conjectures on my part would be quite worthless.

Saluti, G.
GREAT DISCUSSION-THANKS GUIDO. look i come to praise Cesar, not to.. well, you know. but your information yields a lot of points which reinforce what i have experienced. JRDG welcomes you to participate in a grand experiment. Jeff is one of the best pair of ears you could want and he never tires of advancing the goal
of sweetness combined with an equal measure of transparency. the caveat is of course that without a large bank account one can only play this game once in a great while, if at all. I had wanted a Model 8, but ended up with a used Levinson 23.5 instead due to $$ of course. long time later i had a good time with a Krell FPB-300. only after hearing the Pass 1.2 Class-A amps did i decide after a few more years of getting the Rowland 12's. But the left channel power supply made a disturbing noise, and after sending it in for repairs, it came back with the same exact problem. Kicking myself for paying a big gob of money for them and getting a "gee, that's too bad" from the dealer, i was
not inclined to see where Rowland's experiments were going to go. as it turned out, not all that well for a good while. I have no doubt that the 725's for $30K are "probablu" nothing less than incredible, and not too much money considering what they can do (with all of the other necessary and expensive components included set up in an excellent listening environment).
but wait- if the 825 is even better, then what?
anyone still running a Levinson 33H amp can STILL lay claim to a very solid performer- TONS of clean power and build quiality and sound quality that kinda "smooshed" the Rowland 12's in a number of areas. Just no diamond-cut aluminum (this covered the entire amp btw). I long for and HOPE TO SEE
a product, no matter who makes it, that holds its own for at LEAST 5-7 years.
that will take a lot of research, and a lot of field testing. but i don't give a crap (pardon my french) if it is a black square box with a button on the front and an LED to tell you it's on. hide it behind your speakers if you want to, but make it sound like the angels have descended and are singing a happy tune. and keep the prices down. i wonder if Hegel from Norway is as good as some claim (a good example)?