Review: Jeff Rowland Design Concentra mkIIp Amplifier

Dave, I too have been very impressed with my Rowland Concentra II and I have owned various tube syatems in the past. I am still waiting to find faults with the unit. I have been happy with Cardas Neutral Reference Speaker cable and interconnects. CD is Phillips SACD1000, and VPI Aries JMW 10 Shure V15 type Vmx. Speakers are Nestorovic 5AS MKIV. Jallen

I've also had the Concentra II for just over 6 months now and am amazed at how it reproduces music. I've found it really synergistic with the rest of my system: LP12/Lingo/Graham 2.1L/Glider M2, HT Pro-9 Plus, and ProAc R2's on Rix Rax stands. If it has sins of omission I've yet to find them. The system flat-out sings!

Dave, I have a Concerta II as well. I have been experimenting with cables lately. How did you come to choose the Cardas and did you also audition the Golden Reference Speaker cable? I am having quite a hard time getting a cable that just sounds right. Otherwise I love the Rowland and wouldn't give it up.

Jwt-
You should try the Audio Magic cables and speaker wires (current production)- their Sorcerer models on up.

I've heard nothing near them for clarity and musicality. Some people find them "bland", but we've found that's because something downstream can't respond to the small subtleties these cables can pass- they do not make the dynamics "off/on"-sounding as some cables; instead are capable of the most graceful swings.

On the other hand, there have been some we know who have found them "harsh", but we've found the downstream components or wires cannot handle the complicated, quickly-changing signals these wires can pass- they do not throw a haze over complicated signals, and those complex, super-quick signals "overwhelm" some gear/wires.

For these tests, we play half-track master tapes directly into Rowland and Edge amplifiers, and into Audio Note, Manley and VAC tube amplifiers. Regardless of amplifier, opinions on their cables' sound are consistent. We have compared them to the Cardas.

Best regards,
Roy Johnson
Green Mountain Audio

Hi!

Great to see so many music lovers using the Concentra II - like I do. It replaced a AVM pre-/power combo and an Ayre AX 7 intergrated as well as my Levinson integrated. The standard C II is extremely smooth with greta soundstage and an absolutely coherent sound - but with the typical Rowland roll off in the hight. I now use a modified C II - more speed, more timbre, more space and more details. The best power cord to match is Electra Glide Mini Khan Plus - adds a lot of power and speed.
As gear I use: Transrotor Fat Bob S with modified Rega RB 2.6 tonearm and a Shelter 501 cartridge. Wadia 860x and Sonus Faber Cremona speakers. As cables I use Tara Labs The One ISM Onboard - speaker and IC´s as well as Electraglide cables.

Yeah that was nice of you Ovature. And by the way it also could just be that synergistically it worked well in their systems. Of course maybe they just haven't heard better cause you'd know that for sure. How bloody presumptuous.

Ovature, what speakers were you trying to drive with the Concentra II? I have heard the problems you describe when amps were not warmed up (Concentra I was very grainy when cold) or when an amp had insufficient power for the speakers it was trying to drive. When underpowering speakers you get volume but it's unpleasant. As for Dave's review, well, by coincidence I heard the Concentra II at Dave's house and to my ears his review - on his speakers, in his home - is pretty much on the money. I would perhaps have added that the unit does not have the "tube palpability" that many hobbiests seek, so it might not be for every taste. And we definitely did not open up the unit and look inside. The II sounded more liquid to me than the I, by the way, and crisper and cleaner. As for what else I've heard, well, you name it. I've got 20 years experience as an audiophile including owning lots of gear and visiting many stores and shows (CES several times, etc.). And of course opnions and tastes among hobbiests do vary.
Art

ps: Shortly after the Concentra II became available, Rowland began to migrate to a different technology for their amplification. This could account for the short shelf life of the C-II, if it in fact has been discontinued.

I ended up with Synergistic Research Absolute balanced interconnects from the Rowland to an Ayre CD-5xe, SR Absolute 10ft. Speaker cables to Vince Christian E-6 monitors/dedicated Sistrum custom stands. SR Absolute Power cords to the Rowland and the Ayre, with a SR Master Coupler X-2 from a Exact Power EP-15 to a Dedicated 25 amp circuit wired with Cardas 10 Gauge in- wall cable to the main panel. This Cardas wire is six nines copper with teflon wrap on the wires. My equipment sits on a SP-5 Star Sound Sistrum audio rack with 1-1/2" thick maple shelves. The Ayre then sits on Black diamond racing cones/carbon fiber shelf squares #4. The Rowland sits on the same maple shelf material but uses Finite Elemente Ceraball feet. The bass is filled out with a small unit Paradigm Seismic 12 sub connected with a SR Phase II balanced sub-woofer interconnect (killer) and another SR Master Coupler X-2 power cord. The SR Quattro is next in line for me.
The room is filled with echo buster room tunes. With the volume up to about 65 on the Rowland the sound opens up big time and fills the room. The detail is astounding. The Rowland is far from being a piece of junk. The Rowland is mighty powerfull. My Vince Christian E-6 monitors will clip at about 78 on the Rowland but its way to loud anyway. I turned it up by accident as well my son did the same thing, lucky not to have blown the speakers. All I can say is the better the power cables, interconnects, speaker cables, and conditioning the lower the noise floor, the cleaner the sound and the more realistic the sound becomes. The Rowland thus far will hold its own against any Solid State Amp bar none. Using the Rowland in balanced configuration, matched with another truely balanced front end such as the Ayre CD-5xe and then you will hear sound like you have never heard before. Authority and power beyond belief. The Seimic 12 is incredible as well. Ihave a Revel B-15 as well but its not needed in my stereo room so Ileave it in my Theater Room which is another topic altogether and equally as awesome as my two channel. Once again the cables, power and equipment stands make all the difference in the world.
Happy Listening and all good things come in time, hard work and lots of money, above all patience and more patience and more hard work. Gotta Love this hobby.

Ovature: strange comments about the C II. Never ever heard of any C II user that complained about build quality, ergonomics or sound quality. The build quality inside/outside is world class and the sonics of the C II are more stable, transparent and dynamic than the original C I with better frequency extension on top/bottom. Don´t know which problems you had with the C II but normally the C II is a great performer in its price class.

The Jeff Rowland Concentra II is wonderful sounding and very well built. Ovature must have a hearing problem. The Concentra II is one of the finest sounding integrated amps I have owned. I also had the Mark Levinson 383 and many separates. I much prefer the Concentra II over the ML 383 and it performs better than a handful of well known separates.

Ovature,
What type of integrated do you have that is so much better than JR. My CII is still working flawlessly and its over 12 years old, still looks new too. I am using SF Auditors and some SR AR cables to good avail. I took a look inside the piece and thought it was quite well built even though hard to get inside. You and other high end audio folks I run into on occasion have stirred up the same pot of bull stew you are stirring. Something seems wrong here, more like a personality conflict. I blew your response off but after so many years of listening to other components and separates more expensive and very well built top of the line front ends nothing really sounds a whole a lot better than the Rowland to this day, unless its costs three times as much. If Steve did design the guts then it should be good right. I think your are incorrect with this particular piece of junk as you put it, what a classless comment. Its a classic not your comment and well deserved. Heck I can still sell it for what I paid for it. Hopefully you have found the illusive audio heaven cause it sounds like it could help you. Lastly JR is a gentleman all the way, to the bank.

Hmm JEFF ROWLAND has ALWAYS designed beautiful gear! Krel is NO WHERE near as good! You must have been eating macaroni and decided to stuff your ears with it!

Agree with orgman above,I’ve had the Concentra II, Krell KAV300i, Perreaux and Plinius integrated amps,None sound as beautiful as the Concentra,Jadis DA60 gets close but is unreliable, PureAudio One surpassed the Concentra but the company is no more :(

Ovature,
Please stop this nonsense. There is no other way to describe what you have written here. Concentra dark? Two dimensional? While everybody is entitled to an opinion, it seems you never heard JR Concentra.

I am now listening to original Concentra I, shocked how beautiful it sounds. (Never heard JR amps before).  I am considering buying it, however would also like to listen to another well respected amp from around that area (at least in Europe) from Denmark - Gryphon Callisto. 

BTW, in my main system, I use Krell KSA100 mk2, one of very few I actually like. The more modern ones are in my opinion nowhere near as good sonically as the 100mk2. Unless you are talking about D"Agostino's at 30 times the price... 
Best regards to all happy owners and fans of JR Concentra. Stay safe 

For your information, I personally owned both the concentra 1 and the 2. The 1 sound smooth but boring and somewhat dark. The 2 was more lively but grainy sounding. So before you put your foot in your mouth again, understand the circumstances. I owned both pieces and I think they suck.

@ovature interesting comment, particularly since we have no frame of reference as to your ancillary gear. There has never been a grainy sounding piece of gear made by Rowland, so if you truly heard that, it can be credited to something else in your system.