It is a very nice looking one box amp and sounds very well.I am using it with meridian 508.24, Wilson Benesch ACT 1 speakers with satifactorily.

This is the first time I am talking about an audio equipment.I have owned JRDG Concentra for about 8 months already. I upgrade it fr a full Krell setup ie. KRC-3 pre, KSA 100S power and KPS 30i Cd player. You might say that it is a downgrade but I actually prefer it to my Krell set-up.
Finish is first class and I would safely say that it is the best intergrated amplifier (non tube) avaliable. And if you play vinyl, you will get the quitest phono card in an integrated amp.
This amp sounds good with most speakers but if you owned a Sonus Faber, you are not doing the speaker justice if you don't at least give it a demo.

Associated equipment:
Meridian transport 500
Meridian 518
Krell KPS30i CD player
Marantz CD99DR Transport
Pro-Ac Response 1SC
Audio Research Intergrated amp
Krell KSA 100S
Krell KRC-3
etc, etc.....ah yes... Jeff Rowland Concentra!

I've heard the Concentra described as "tube-like", but, given my limited experience with tube equipment, I don't think I can really comment on that particular quality. However, the treble, midrange and bass are superbly reproduced in a very neutral manner with no coloration (not too cold, not too warm).

None. System matching is key and those who have not preferred the sound should consider source or speaker changes in order to get the best out of this amp. Originally, I had a mid-fi system and upgraded slowly, starting with a Wadia 830 CD player. I then bought my Concentra after auditioning the two together. Afterwards, I auditioned this combo with a pair of Acoustic Energy AE-1 Signature mini-monitors (which I subsequently bought), thereby assuring system compatability. By the way, a word of advice to Justy, who in the previous review complained about his power bill secondary to the lack of a power switch: use the mute button, it functions as a stand-by!

I can't say enough wonderful things about this amp. Before checking the Concentra out, I was actually auditioning pre-amp and momoblock combos. With this component, I get excellent sound, a relatively compact size and an overall decrease in complexity and cost in terms of components and interconnects. Yes, everybody thinks that Jeff Rowland owners are just swayed by the looks, but I don't know of a single audiophile that would that would trade sound quality for external beauty (only millionaires trying to impress the uninformed would do so).

This is as excellent amp. It looks fantastic and the build quality is awesome. The convenience of the remote is great, particularly for getting the balance right. If you have never been able correct the balance from your listening position you have no idea what a difference small changes in balance can make to the sound quality and the soundstage. The transparency of the Concentra defies belief with music sounding starlingly real when everything is set up correctly. I use the Concentra in Balanced mode with a Meridian 508-24 and Von Schweikert Research 4 Gen II spearkers wired with Kimber Select. In my opinion all of these other products are also rate a five!!

Transparency, detail, holography

lack of warmth, loose base

I have used Jeff Rowland products in my systems for over 15 years. I have also used Audio Research and Krell in my system have have had Mark Levinson on loan several times. My listening biases are:

1. Holographic soundstaging

2. Liquid midrange with no bump in the upper midrange

3. Ability to resolve the subtle nuances in tonality or dynamics which give music (and musicians) its character.

I have used the Concentra for over two years now and have had other pre-amps in my system during this time (I use the Concentra as a pre-amp only). The Concentra is one of the few pieces of equipment I have ever had in my system which allows me to be transported from my listening room to a musical event. I hear the pacing of the music and each instrument contributing to its sound. I hear the counterpoint between instruments. The music has a life like quality, in real space and time. You hear the bloom of the instruments and their full decay.

Is it perfect? No, no piece is but its the closest I've gotten to the real life musical experience. It base reproduction (not a strength of my system in any case)is questionable. It provides the music quality of base, but does so with a slighly bloated sound; seems to lack the control I have experienced with the Krell or Mark Levinson. Also, it has lost some of Jeff's signature sweetness in the midrange, it no longer sounds like an outrageously good tube pre-amp. This is the reason I use it as a pre-amp only. The Concentra in combination with his earlier amps (Model 5 or 7s) gives the best of both worlds- sweentness with incredible detail and transparency. Given what the other competing pieces cost, the Concentra was a bargin and added just the right synergy to my system. I think its truly one of the benchmark products of the high end thats affordable to mere mortals.

The System:

Modified WATTS
CD-2
TNT Series 5
Clearaudio Insider
Highly modified Revox with master tapes (30ips) I recorded
Rowland Model 5
Transparent Audio Reference Interconnect
Shunyata Power Cords (Black Mamba and Viper, Series II)
3 dedicated 30 amp circuits with Wattagate power outlets
Dedicated listening room set up with a TEF

Similar Products Used:

Coherence II, Audio Research

build quality

Recently purchased new system from source(CD) to speakers. Solid-State amps compared included Krell seperates(FPB amp), Classe seperates and integrated, entire Linn and Naim Systems. Tube amps from BAT and VAC also compared. Tough to make broad comparison as speaker's used varied from Audio Physic Virgo to ProAc 2.5 to models from JM Labs, Naim, Dynaudio(3.3) and Eggleston Works(Andra). Lucky enough to use similar source for much of testing, either new Linn Genki CD, or Naim 3.5 w/ flatcap(tested Krell amps with Krell CD though).

Music listened to was a range of opera(Cecilia Bartoli Live in Italy, Track "4 especially), solo cello(Bach Suites by Rostropovitch, sp?), classical(Respighi, outstaning test of dynamics), pop (bob dylan nashville skyline) reggae(bob marley exodus gold cd) and jazz(coltrane ballads).

Not going to bother comparing the Tube amps to the Solid-State. I'll just mention that if you can make a tube amp that won't fry my kids fingers, can drive a reasonable load and be left ON all day, then you wouldn't need solid-state. The VAC renaissance 30/30 MKII(w/ Vac preamp) managed (just) to drive Audio Physic Virgo speakers into the land of sheer bliss. Vocals were riveting, soundstage was immense, dynamics were musical and exciting(no no, not as intense as all Krell w/ same speakers)...around 18,000 for system less source(Krell CD for test), but best sound hands down that I heard. I decided not to buy TUBE in the end, but still dreaming...on to...

Solid-State - Krell seperates (FPB 200 amp, medium level preamp and CD) sounded completely uninteresting w/ Virgo's compared to the VAC Tube, lifeless, cold, quick at the expense of experience, if that makes any sense...I asked the dealer if they had any other solid-states to try, he said "that's the best" and I left. If anyone wants to rebut the Krell comments, keep in mind that I also auditioned a FPB-600 with AudioNote Pre-amp and Eggleston Works Andra speakers, source was Copland CD and, well, the problem could have been in something other than the Krell, but the strings were not 'there', neither was percussion despite the eggleston double-bass set-up, have to give them the vocal award though, extremely natural sound, you could tell that the TUBE was coloring a bit after this set-up.

Moving quickly through the all Naim(too "soft", easy on the ear but not engaging enough at these price levels) to the all Linn(gear just below the top of line models) which with Linn speakers made me think I was suddenly in a hospital emergency room getting sliced and diced by every analytical note(tried with dynaudio and naim speakers and worked better, but still not getting anything like the VAC sound and still spending a fortune).

Next i took a step "down" and auditioned Classe, the seperates left me with the impression that my Threshold Amp was just as good, maybe i should just add new speakers(have old KEF Reference 2.3 and Vandersteen 2's), tried the new Classe integrated amp and almost bought it(think of the extra money i would have for CD's and records!), the unit did everthing fairly well, nice soundstaging, clear tones, tight bass, but clearly lacked the excitement and sense of prescense which I experienced in the TUBE set-up and which was the reason i started my new HI-FI search...back to the drawing board.

Came across the name of Jeff Rowland in an audio mag, read a little research on the web site about the attention to build quality, the viewpoint on the importance of the Volume knob, etc etc and made an appointment to audition.

The Concentra(which by the way is the most beautiful piece of audio gear I auditioned, but DON'T CARE about that) was connected by way of Kimber Bi-Focal XL's to ProAc 2.5, source was "budget" Wadia(which is maybe not fair?). Pulled out the audition CD collection, popped in DYLAN girl from the N Country Fair, the one with J CASH also on vocals, and, bang, love at first sound. Dylan's early country picking emerged from a background of total silence, the strings resonating in the air, I play the guitar, and immediately i wished I had an instrument there to play along, then the vocals, totally natural, no CD strain, and J Cash went deep, man his voice can drop off a cliff, it was all there.

I was so excited I popped in the Cecilia Bartoli to really check the vocal, blah blah blah, i went through the rest of my CD's and didn't experience any shortcomings, bass was very full(not as tight and articulat as the Virgos), sound stage was deep and wide(though speakers didn't disapper like the Virgos - FYI, I went back to listen to TUBE set-up again after). I had found the TUBE presence, naturalness and musicality(almost, almost) in a unit that I never had to turn off, didn't require an expensive interconnect cable, was built like a tank, and ALL THINGS CONSIDERED, is a good value.

I bought the Concentra amp, the Kimber Bi-Focal XL and the ProAC 2.5, and after extensive break-in on the speakers, am very happy with the results. Source material currently comes from CD and Tuner(if you don't know how good FM sound is with a good tuner, you are really missing something), and i'm in the market for a new record player.

I thorougly enjoyed all the time I spent researching and auditioning my new Hi-FI. Equipment was purchased in NY, London and Paris(!), and all the dealers were professional and helpful. I hope this review helps readers, although clearly each person prefers a different 'type' of sound.

GOOD LUCK!!

Similar Products Used:

replaced Threshold Amp

The look ..., Balance input, resonably good sounding

not able to drive low-sensitivity speakers well, a bit over priced

I would say people who buy Jeff's Product are mainly convinced or distracted by its beautiful look (not as many amp as pretty like Jeff in the market).

To compare with Krell KAV300, Krell wins in any respects in term of dynamic, transient response, high and bottom extension and smoothness in mid range. I don't own Krell or Audio Research CA50 but I just happened to listen them in my system. My system consists of the following. However, Jeff Int. Amp. does not sound like powerful enough to drive my WATT 5.1 even it is said to 100/W per channel.

ARC SP15 II
ARC Classic 150 Mono Block
WATT system 5.1
Well-Tempered Black Classic with Arm
Clavis D.C.

Similar Products Used:

Krell KAV300, Audio Research Int. Amp,