I received the M700s on Monday, April 3rd.
The casework is well done. No gaps, raised edges or screws akilter. They are a nice clean design and very unobtrusive looking. I really like having two sets of speaker binding posts. It makes bi-wiring much easier.
Amp: Krell KAV-3250 (250 watts x 3 channels), used to drive the main speakers and a passive subwoofer.
Speakers: Krell Resolution 1 (main), Nelson-Reed 1204 passive sub (4 12" woofers). The processor is set to crossover to the sub at 40 hz.
Preamp: Krell S-1200U home theater processor. Yea, I'm a Krell guy, maybe something to do with watching Forbidden Planet when I was young.
CD Player: Sony BDP-S5000ES Blu-ray player
Analog: Music Hall 7.3 turntable with an Ortofon Bronze cartridge
Phono Preamp: PS Audio NuWave Phono Converter. I love it.
Power: PS Audio P10 and Powerplant Premier.
Power cables: PS Audio Statement and Plus (xStream, I think), which I believe are some of the earliest power cables PS Audio came out with.
Interconnects: PS Audio xStream digital interconnect from Nuwave Phono converter to processor. Pure Silver Sound Octet with locking RCAs from preamp/processor to amps.
Speaker Cables: Pure Silver Sound Octet bi-wired from amp(s) to speakers
My system is in is a combined home theater and stereo room. This family room is open to the kitchen behind it, as well as having open hallways to the living and dining rooms. The family room/kitchen space is approximately 18x28'. The ceilings are 10'. Internal walls are 2"x4" studs with drywall.
After the initial hookup, there was a hum coming from the speakers. I wouldn't say it was loud, but from the listening position, it was obvious. I was not able to reroute any cables, as that would require taking apart the shelves. I didn't want to do that until I decided whether I was going to keep the M700s.
My solution was to use cheater plugs. This removed most of the hum. I could only hear it when I had my ear within 6" of the speakers. I'm concerned that putting cheater plugs would affect the sound quality to some extent.
The initial sound was thin, though there was good detail. No point in going into any more detail at this point.
The M700s have been on continuously since the afternoon of April, 3rd. For the most part I have been playing music 24x7. I've also used Purist Audio Design System Enhancer burn-in CD during the past few weeks. I would say the units have in excess of 400 hours of time on them during which they were actively playing music.
There was a two day period when I switched back to the Krell amp so I could compare the sound more closely, and a few other times where I switched back to the Krell for a few hours.
One of my concerns is that the speakers may present a difficult load for the M700s. I don't know how this might affect the sound. From the M700 literature, they can handle a 4 ohm load, and be stable with 2 ohms for musical transients. I found a Stereophile review of the speakers. From the measurements section, most of the audio band is well below 4 ohms, and even dips below 2 ohms at one point. Offsetting this load is the subwoofer, which is powered by the third channel on the Krell. Anything below 40 hz (not sure how the rolloff works, whether it's 6 DB per octave or something else) goes to the subwoofer. Here is a link to that review:
Most of my listening was done with analog (vinyl). When I listened to digital it was done with CDs, I don't have any hi-rez recordings. I feel my system has noticeably higher resolution when listening to vinyl. The downside is the deficiencies of vinyl, such as surface noise, pops, and somewhat restricted bass, along with everything else the analog chain offers.
Overall, these amps are more dynamic than the Krell, so recordings sound more alive. On some songs, singers will harmonize with themselves. It is much easier to hear this with the M700s. I can hear two or more distinct voices, rather than a suggestion of this with the Krell. Comparing the M700s to the Krell, there is greater clarity on vocals. The Krell sounds slightly muddy in comparison.
For the high end, cymbals, and the upper range on the piano through the M700s, it doesn't seem quite as natural as with the Krell. Maybe that is due to the additional clarity, and I need to become used to it.
When a female vocalist goes into her upper range and sings more loudly, it becomes hard sounding, sometimes to the point of being unpleasant. This happened on the Barbra Streisand album Guilty. On the last song, Make It Like A Memory, Barbra starts out singing and it sounds wonderful, but then 2-3 minutes in, she goes into a higher register and sings much more loudly, when this happens, her voice becomes hard, brittle and has a glassy sound to it. This is when listening to vinyl. When listening to the CD, it seems like the dynamic range isn't as great, so her voice doesn't become nearly as unpleasant. The odd thing is that the CD is supposed to have greater dynamic range than vinyl, so I would expect the CD to have even more of a problem with this. When I listen through the Krell, I'm not hearing nearly as much of that hard glassy tone in her voice, either on vinyl or CD.
The M700s produce a more developed soundstage than the Krell. It is wider and deeper. I can hear details I couldn't hear before. Things that were only hinted at with the Krell, and more clearly audible with the M700s.
Vocals, both male and female, are more present and physical with the M700s, as compared with the Krell. I would call vocals more vivid and lifelike with the M700s.
I made some changes to see if I could address the hard sounding vocals. I removed the stock power cables that came with the M700s, and used two xStream Plus power cables. I tried with and without the cheater plugs. The hum was still present, though to a much lesser degree with the cheater. I need to work on that and see if I can get rid of the hum completely. With the Plus power cables, the loud vocals became less hard sounding. However, they still didn't seem natural. I wonder if there is something going on with the M700s, maybe increased distortion (regular or TIM) of some kind, when they are trying to reproduce the higher range in vocals or piano when loud. I don't hear this hard sound when the singer/piano isn't hitting their notes as loudly. I did clean the stylus on the cartridge to make sure it wasn't due to contamination. The cleaning had no effect.
Other material I listened to (on vinyl unless otherwise noted)
Mannheim Steamroller's Fresh Aire III - The Sky has a piano that echos throughout the song. It sounds good, but still that hard sound is there slightly. When listening through the Krell I can relax into that song and just enjoy it. As a side note, I never enjoyed this song until I listened to the vinyl version. It has a dreamy quality to it. Listening through the M700s, I just can't seem to completely relax during this song. It sound good, but it just doesn't pull me into the song, due to that hardness.
Crosby, Stills, and Nash's Daylight Again - Southern Cross sounded exceptional through the M700s. The chorus behind the singer built a huge expansive wall of voices that was wonderful. I've never heard this song sound this good. This song doesn't really have any hard percussive sounds and has a warmer sound in general, so that might be why it sounded so good to me.
Dire Straits first album - In The Gallery, it has some nice cymbal accents throughout, which are beautifully reproduced. Again, I wonder if it is because the cymbals aren't hit very hard. This is their only album I enjoy from beginning to end.
Dan Fogelberg's Wild Places on CD - Forefathers, compared to the Krell, the sound was much more expansive with many details on the mix, which the M700s brought out, which were not nearly as clear through the Krell.
Heart's Little Queen - Love Alive starts out with acoustic guitars and Ann Wilson singing. Her voice sounded much more present as compared to the Krell, where it seems a bit buried in the mix.
Al Stewarts's Year Of The Cat, MSFL release - On The Border sounds very spacious. Al's vocal is very clear and natural. The percussion, guitars, and lyrics combine to create a song that is shimmering and slightly hypnotic.
Supertramp's Crime Of The Century, MFSL release - School is outstanding. There are many details during the opening that are much clearer through the M700s. When the little girl lets out a scream just before the song starts cranking, it made me jump. The soundstage is wall-to-wall throughout the song.
Bruce Springsteen's Born In the U.S.A - I'm On Fire is a very simple track, guitar in the right channel, wood block (I assume) and cymbals in the left, and Bruce's vocal in the center, along with bass drum. There is also a synthesizer playing as a wall of sound behind everything. It's a haunting song. Through the Krell it doesn't quite have the same emotional impact.
Judy Collins' Colors Of The Day - Farewell To Tarwathie had the largest soundstage of anything I listened to. I wonder if Judy's vocals were recorded in a church. There was a very natural spaciousness and reverb to her voice, and the dynamics of how she sang the different verses drew me into the song.
I very much enjoyed the M700s. Visually, they are very clean looking. It's also nice that they don't get very warm. After an hour the Krell gets almost too hot to touch. I live in the Southwest, and during the Summer, they would bring the room temperature up by 5 degrees or more.
Soundwise, the M700s are very clean sounding. I would not say they are lean, but I think the Krell has a little more "meat on the bone". Acoustic guitars through the Krell provide a little more of the body of the instrument than do the M700s. However, this is at the expense of resolution. Perhaps this will change as they break in further, or perhaps it's a cabling, speaker or some other issue. The M700s provide a clarity that the Krell can't quite muster. The Krell is over 15 years old, so maybe some of its deficiencies are due to its age.
I am concerned about the hardness when vocals or instruments increase in volume during a track. I don't know if this will go away over time, or if cables, speakers or some other component is a factor. I wonder if balanced interconnects would make a difference in this regard. I do dread going down this path, as I fear I will get on the upgrade merry-go-round and not exit it for awhile.
There were times when I was listening and I couldn't completely relax into the music. It could be because I was trying to be analytical about the amps, and that got in the way of just enjoying the music.
At this point, I am planning to keep the M700s. I will continue to listen and make a final decision in the next week.
Lastly, since going through this process I now have more respect for the reviewers of stereo equipment. Critical listening takes discipline and staying focused, which I don't think I could muster. Not to mention putting it into words in the form of a coherent review.