Any Jeff Rowland owners?

GuidoCorona said:
Hi Kiwi, did you review C500 or C250? The C250 lacked a PFC unit which helps to protect the ICEpower module from residual grundge and ripple... Hence C250 would sound a little sterile, somewhat like the M201 mono amplifier.

C500 did have a PFC unit, which was however different from the one found in the M312 stereo amp.... For some reason, the 312 sounded always amazingly musical, with instrumental and vocal images fully alive and fleshed out with harmonics and microdynamics (at least compared to its contemporaries), while C501 did not seem to reach the same degree of refinement, and could not yield the same emotional involvement to me... Yes, I heard them at length in the same system during the same session.... Rest of system was a Boulder CDp, Capri (original) on M312, and Vienna Die Muzik speakers. It is possible in theory that C500 may be handicapped in some way by the bank of output capacitors post power conversion module... They were designed to enhance authority and macrodynamics, but they might have been slightly detrmintal to subtlety.

Furthermore, C500 required a complete break-in of about 600 hours, before which it would sound sterile and hard.

You are correct also that the casework of Continuum S2 is based on the original C500. Internally things are entirely replaced/redesigned.... Different PFC unit, ICEpower is gone in favor of Pascal technology, different transformer coupling, and the preamplifier circuitry is that of the new Capri S2, which is very different from the original Capri.

There is a CS2 section on the Rowland Knowledge base where you will find 20 short articles with some more information:

Continuum S2 Integrated

Bottomline is that I had some reservations about the performance of the original C500, while what I heard at RMAF 2014 from Continuum S2 and the Raidho D1s -- particularly on the third day (Sunday) -- was magical.

Guido
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Thanks for the reply Guido and for the link.

I auditioned the C-500 twice. The second time it had over 500 hours on the clock and I left it on for 48 hours before the audition began. The C-500 sounded dreadful on cold start and took forever to stabilize in temperature and come on song. I believe the C-500 internally used a pair of 501’s for power amplification and the Capri for the pre-amp section and come what may, I just could not connect to the music via them. A summary of my review is reprinted below:

“SUMMARY

What do you listen for when you play your system?

Those who want their sound clean and analytical, with carved from stone bass will find the Jeff Rowland near perfect. There is no mistaking this amplifiers power, headroom, transparency and resolution with the later underpinning the amplifiers ability to demystify complexity, allowing you to see from the front to the back of the soundstage. In pure high fidelity terms the Jeff Rowland is easily the most impressive amplifier I’ve auditioned to date. In terms of speed this amplifier can turn ‘on a dime’ and deliver fresh insight into your music library that is of the – “smack you in the face, jaw dropping, how could I have not noticed that?” kind.

One question however lingered – how long would one remain impressed and satisfied by attributes of high fidelity before the ‘rose tainted glasses’ gave way to more circumspect analysis anchored around physical connection to the music itself? The problem for me was the Jeff Rowland was not involving enough. Other amps feel better nourished, more sinuous and harboured a fluidity that invited the listener in and held you there enthralled. Sure I was impressed, enthralled even; by the Jeff Rowland’s big sound with its sparkling almost directly coupled clarity. But this misses the point which is sometimes amplifiers can get so wrapped up in the means of music delivery that they forget the meaning of the message itself. Put another way the Jeff Rowland Continuum 500 scores the highest grades for innovation, technology and musical delivery but fails, at least for me, and in direct comparison to some other amplifiers here, to recreate the emotional intensity of the experience.”
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At that time the C-500 was compared with the GamuT DI-150; The Gryphon Diablo; the Plinius Hiato; AMR AM-77 and a couple of other top of the line integrateds.

While the link you provided does give some interesting technical information I am really wondering how the S2 differs sonically from the C-500? Do you have any insight on that? Not everyone was impressed at RMAF 2013

Ultra High End Audio had the following to say:

“This was one of the most disappointing rooms of the show for me. Given the praise Jonathan Valin has been lavishing on all things Raidho of late, I expected to be at least mildly impressed with the Raidho D1 standmount loudspeakers….. pairing with the brand new Continuum S2 integrated amplifier ($9800) what I heard was boomy, one note bass, an uninvolving midrange and an edgy treble. Soundstaging was imprecise….”
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This seems to be quite different from what you heard? Could we put the differences down to inadequate run-in for the Rowland? I did not the photo showed the Raidho’s parked on what looks to be marble tiles – which IMHO is a sin.

I am asking the question because I have an Esoteric Kilo Zero Three source (mounted on Nordost Sort Kones of course) and Raidho D2 speakers and looking for an integrated amp to complete the picture.

Thanks
Ralph
 
Hi Ralph, Raidho speakers need long-drawn setup, particularly in small rooms, like the 13x19 suites at RMAF. If the UHEA reviewer visited the suite on the first day, or in the morning of the 2nd day, he would have heard traces of peakiness in the treble because CS2 was still relatively underexercized, and more than some mid-bass over-resonance from D1s. The Rowland team continued to dial in the speakers until they achieved optimum setup by Sunday... having said that, D1 would enjoy a breathing space that the RMAF standard suites simply won't afford to them, hence one needs to factor in the limitations of the environment... Admittedly, A double sized suite would have yielded enhanced synergy, but on Sunday, bass pitch unspecificities were hard to detect, except for occasional traces in double-bass bowed parts of large symphonic works.

Raidho D1s were set on top of blocks of carbon. I do not know what was between them and the carpet... Sorry, I have been blind as a bat for the last three decades, and do not do pics.

Concerning the sound of a cold C500... Yes, I fully expect it to have sounded horrid... That is an unavoidable characteristic of ICEpower modules coming out from deep sleep, inside amps from any manufacturer.... They do take about two days of exercising a signal before they yield best performance... Past full breakin, that is.

If I were to make a comparison from memory between C500 and CS2, using the 2nd movement of Dvorak's new world symphony with Bernstein and the Israel Philharmonic... C500 yields an intro low brass chorus where the stage is relatively two-dimensional, and the cuivree has hints of jarriness, so do the Tympanis at the end of the first cadenzas... The double bass line in the first thematic exposition is definitely well pitched, but has a wooden and non denomoinational quality to it... Yes, orchestral instruments are "transparent", but they lack ultimate harmonic and microdynaic subtlety... There seemed to be residues of edge... And the build up to the concluding cadenza on tutti of the first thematic exposition does slide into some further jarriness and detectable treble cross-modulation.

All above defects were completely absent on the Continuum S2-based system I heard. Staging in the chorus projected in 3D... Cuivre meant that the brass resonated, not that upper harmonics fought with one another to generate the nasties.... Tympanies sounded intense and present, rather than inducing you to avert your ears.... Double was pitched starting from the fundamental, and showed harmonics and small dynamic shifts... I heard no traces of treble cross-modulation... The experience was emotionally immersive rather than clinical.

As for technical details on S2... When I receive a full briefing, I will post them... Meantime, discount what you heard from old and withdrawn C500... 'Tis a dead horse. Beyond the casing, there is no commonality with S2...

G.
 
Davey, I am glad that ICEpower is of your radar... It is largely off Rowland radar as well, Only the very entry level M125 is still based on ICEpower. Conversely the balance of current amp production, like M525, Continuum S2, M625, M725, M825, and M925 utilize enormously more musical power conversion technologies.

Saluti, Guido
 
They all use variations of Rowland's power factor corrected switched mode power supply (SMPS) design, but the 625 and 725 use class A/B output stages. The 825 and 925 use nCore class D output stages.
 
Hi Davey....

the output stages of M625 and M725 are based on a moderately high bias class A/B design without overall negative feedback. Conversely, M825 and M925 are even more sophisticated designs with Ncore NC1200 modules in the output stage which run in class D.

I have owned M625, M725, and now M925.... M925 are superior by several country miles... Runs wide circles around the other two.

I realize that you and so many others in our community,understandably experience digestive cramps when hearing the words "Class" and "d" strung together.... For a very good reason.... By themselves, the old ICEpower ASP and ASX series modules were quite unbearable, as exemplified by the shrieking boxes of way too many low end integrators. I have experienced only two manufacturers who have managed with a lot of work to extract emotionally involving music from ICEpower: Bel Canto -- only with REF1000M (mk.2) monos, and Rowland -- with M312 stereo... If there are any other ones, I have not heard them.

The good news is that we are now in a brand new ball game, with class D modules that bear no resemblance to the previous generation.... Hypex Ncore NC1200 designed by Bruno Putzeys, and at least some Pascal modules are far cries from those inherently rough class D creatures of old which had only hidden potential of moderte refinement... The new breed of modules appears to be an inherently hi performance starting point for amplifier designers... Even basic Ncore implementations like the Merrill Veritas monoblocks deliver musicality that is at least uncommon in amps at higher price points. See my Veritas article at:

Merrill Audio Veritas Amplifiers

Other engineers, including Bruno Putzeys himself with his own Mola-Mola Kaluga monos, as well as jeff, have instead created amplifiers that leverage the NC1200 as a springboard for their own advanced designs. M825 and M925 in particular, are, to the best of my knowledge, the most sophisticated amplifiers on the market that incorporate the stock Ncore NC1200 power conversion modules. Amongst other things, the Rowland devices, instead of including the Hypex unregulated Ncore SMPS1200/700 power supply, have implemented a multi-regulated 2500W custom SMPS prefixed by a PFC-based rectifier. As you can read in the technical information on the Rowland knowledge base,

Model 825 Stereo Amplifier

Model 925 Mono Amplifier

Ncore technology is but a small part of the M825 and M925 design. This is reflected by the sonic difference with the delightful Merrill Veritas -- a difference that is congruent with the respective pricepoints.

If you ever get the audiophilic itch to listen to the new Rowlands, Matt Aikawa is the dealer in California... He has considerable experience with the new series, and might be able to arrange a listen:

Matt Aikawa
Moraga, CA
Tel: 1 510 206-1766
[email protected]

Saluti, G.
 
First we have this:

daveyf said:
Like you, I have the utmost regard for all of Jeff's products. I believe that they are ALL classics in their own right and will hold a very well deserved place in the history of audio.
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And then we have this statement:

daveyf said:
Guido, I for one, cannot quite understand why Jeff has so much love for the ICE power modules. Of all his products, I feel that the ICE based ones are the worst. Frankly, when I see that an amp has ICE modules, it is no longer on my radar, period. I'm sure this could change, BUT for the here and now, it's totally the case.
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How do you reconcile these two statements?
 
He was referring to the ICE power modules; for which he is not particularly fond of. ...But he has high regards for all other Jeff's products.

Me, I know nothing, only that all the reviews I've read of amplifiers (receivers) using Class D power, are not my cup of soup either.
But then, I didn't read (even less heard) all the reviews and amplifiers out there using the ICE (Class D) power module designs.

* Words are words, but there is a line of thought behind them, a context that we understand and that goes above them simple words.
 
Let's keep things on track here. Someone can respect someone, but also query their use of ICE in their earlier work.
 
Davey, your sentiment of JRDG matches mine as well. I love their classic looks and the house sound they try to achieve in all of their products. But I also call into question their use of some technologies they've used, and it's not limited to just amplifier modules.:weird:

Davey, have you had your Model 8 serviced yet, i.e., recapped?
 
Based on what I felt to be two very conflicting statements, I thought it was a valid question to ask. If everyone doesn't think there was a conflict between the two statements, I stand corrected.
 
Oh wow guys... I just left for a few hours and beer-bottles's gone aflyin' already?!

Davey, your skepticism is quite understandable... And I do respect your apriori preference for the tubier side of audiolife. Unfortunately at shows it is very difficult to find any suite that reflects the true potential of the gear shown... Acoustics is bizarre, the gear is just off the factory floor, synergy with ancillary equipment is often a case of wishful thinking.

If you ever visit Austin, drop me a line.... I will be happy to let you hear a well broken-in M925 under good field conditions... Bring along your own CDs / SACDs of course... Sorry no computer audio.... I am a veritable digital audiodino... If in the end you still find M925 to be an undigestable cup of class D musical tea, that will be perfectly fine with me...

Mike and all.... If you ever visit Austin, do come and visit as well!

Saluti, G.
 
I did see and hear the 825s at RMAF. The Joseph Audio room with the Pearl 3s and the 825 was very musical. One of my top 10 rooms at the fest.

Also, I spent some time talking with Jeff Rowland. Really good guy.

I considered the 725s and the 825 for my Revel Salon 2s. Jeff uses the Salons in his shop. So this is a great match.
 
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