Summary:
i bought my c-j mf2100 used from an audio dealer after trying it for a few days. a musical fidelity xas100 was purchased only 4 months prior, and serving well at pushing the maggie mg-12's ( maggie's need current drive). when the c-j was fired up, the 1st thing i noticed was way more bass...this bass however, had a more rounded quality than i expected from solid state. yet, the experience was satisfing. the 2nd thing i noticed was how smooth the music sounded. i have very good hearing and any brigthness in my system annoys me. a lot of CD recordings are mixed "hot", which makes my pursuit for a balanced system that much more frustrating...till now!!! with the c-j in tow, music previously somewhat threadbare, was now imbued with an envelope of body and fullness the recording lacked in the past. throwing every bright recording i had at the c-j showed this was no fluke, yet most of the detail was still preserved. audiophile recordings were rendered "spot on", bass as tight as a drum and harmonics rich and realistic. i also concur with the other poster on this wonderful amp. you like what tubes do best without the hassles? c-j solid state gets as close as you can get. happy listening ~

Strengths:
body, soul and flesh in midrange ...refuses to get bright w/o giving up detail

Weaknesses:
although very deep, bass could be a little tighter

Similar Products Used:
linn lk100, mc cormack .05, musical fidelity xas100

Summary:
I had (notice past tense) a Conrad Johnson Sonographe Amp which I liked very much. Was able to demo a close-out MF2100 and the improvement was amazing. Well worth the $ to upgrade. Most improvement was in the midrange like vocals and wind instruments. Ditto on the compliments in the earlier reviews.

Strengths:
Clear accurate and musical.

Weaknesses:
None

Similar Products Used:
Sonographe

Summary:
I've had this amp in my system for 6 month's and can say it is one of the best amps i've ever heard.Home Theatre and Music are one of my hobbie's and i like to go around and compare equipement and this amp was completely different in the way it sounded.For a start it is so smooth and relaxed.The relaxed sound is not a slow sound but a sound that makes you FEEL relaxed.Every time i turn up the volume i can feel comfortable not irratated like you do when you turn up the volume on some other amps out there.You can have it past 1 or 2 o'clock and it doesn't hurt your ears,you just wanna turn it up more.This amp also has the looks to complement it's sound.
There's something about Conrad Johnson stuff were all their gear sounds very good.It looks and sounds like they wouldn't just make something to sell it but also to give people enjoyment and this is what the've done with this little beauty.
I must also say that Audio Research stuff sounds pretty good also.
And remember, a house isn't a house till it's filled with music.
Keep pumpin e'm out cj.

Summary:
Great amp for the money. When relieved of bass duty, it becomes far more transparent in the midrange. It also gets human voice right. Could not recommend this amp enough. Unfortunately, discontinued. Associated equipment: CJ PF2 preamp, B&W 805 matrix/ ASW800 sub. MIT cables and PAC. LInn LP12 Valhalla. Adcom GDA600 DA converter feed froma philips player.

Summary:
My system comprises of:Preamp: conrad-johnson PFR
Poweramp: conrad-johnson MF2100
CD Player: Arcam Alpha 8
Speakers: Paradigm Studio 80(reference series)
Interconnects: Nordost Blue Heaven(flat line silver)
Speaker Cable: Nordost Super Flat Line Gold MKII(biwire cable)

With the system mentioned above the only component not quite in place may seem to be the poweramp. Although the MF2100 is rated at 100w/ch x 8ohms, driving a pair of Studio 80s with rated input power of 250w - 300w at nominal impd 6ohms, it is capable of exceeding transient responses equivalent to a 200watter. Infact I tested the amp side by side with a 200w/ch poweramp along with a Potentiometer and Sound Pressure Level analyzer, and found the MF2100 to be in total control. Although the 200watter had much more punch, it did not have all the depth and finese compared to the MF2100. It also recorded double the amount of current and voltage drive, including the SPL levels of the Studio 80s which seemed to make the sound stage expand each time dB levels were attenuated in 3dB steps. This is partly due to the MF2100's design. With a JFET input stage and a MOS-FET output stage, what we have here is an amp that can deliver double its rated output power in short term peaks and still have ample amount of power for the long term passages. MOSFETS have proved to be the number one choice for power and finese reproducing sound equivalent to that of tube designs with "solid-state slam!" This is where conrad-johnson's moto "Just sounds right" couldn't be expressed any better. However, there is a small catch to this entire senario. If you have carefully noted the components used in the above system, only then will you understand why this is a very high-definition system. The cj PFR preamp is probably the best preamp I have ever come across in its price range and it is a match made in heaven when coupled with the MF2100 or any of the other MF series. I also have the MF2300, which takes you at a higher level of definition. I cannot imagine the MF2100 performing any better when coupled with the PFR preamp. Although I have used a vast number of highly regarded preamps costing twice the price, the overall sound synergy obtained between the PFR and MF series power amps simply cannot be matched, unless of course you were using cj valve designs, which are of course in a league of their own. Cables and interconnects are extremely important when considering true high-end definition. If any of you out there have not yet tried Nordost flat-line cable, you are missing out on a new horizon of musical detail! I will close my review with a small coment, "conrad-johnson, defining music at a higher level."