October 2013

iQ Audio M300 Monoblock Power Amplifiers
Small is beautiful!
Review By Rick Jensen

  We start off with a cliché, that small is beautiful, in talking about the very fine new M300 monoblock amplifiers from iQ Audio. It is worth examining that cliché just for a moment. I know I have read it or its equivalent in other reviews, evaluations that are very positive and complimentary. But, and maybe I am revealing my own biases here, I often read into those compliments a qualifier; "the Supersonic MTX-8000 is a superb component, in spite of not being very big at all". As though big were a virtue, and a sine qua non of quality, all by itself.

Most of the great amplifiers one might signal right now are pretty large, and heavy, and imposing (with the exception of some ultra-luxe SETs). There are good reasons for that, and as we know, they have mostly to do with the inefficiencies of most designs and the need to get rid of excess heat. I lust after many of those amps as do most card-carrying audiophiles. I like big toys, especially ones that are beautifully made. The M300s are different. No, they are not an assault on the state of the art. But they are pretty darn good, in spite of being small. And though small, they have big ambitions.

Good Things Come...
The amplifiers arrived in two boxes, which though much less imposing than most components, are quite well packed. Each box is about half again the size of a shoebox. Setup was a breeze. I placed the amplifiers on the floor just inside each of my speakers, using the two-meter Kimber Select cables I use normally. That said, one could place the M300s behind, in front of, or next to almost any speaker, and use a very short cable run. I just didn't have any shorter cables on hand.

The M300s are compact, well-machined, neat squares with rounded corners. They are about 7 3/4" square and 4" high with their supplied rubber feet. The feet were perfect on the hard floor of my listening room. While they are tall enough for a flat rug, those with deep carpeting might want them on stands or supports to raise them a bit higher. And because they are almost totally without any perceptible vibration, placement on the floor seems to work quite well. I also placed them on my Grand Prix Audio amplifier stand and did not hear any difference at all. One nice touch is that there is a very attractive and cool blue light on the front panel indicating when the amp is turned on.

Like many switching amps, the M300s are very light. Without any heavy transformers or heat sinks, they weigh only seven pounds each. But lest one think that this makes for a "lightweight" unit, one has only to look at the connectors. The "iQKord" power cords are hospital grade connectors made for iQ, very robust with good RFI/EMI blocking, and make a very solid connection at the rear of the unit. Even more impressive are the binding posts (called "iQ Torque"). These are heavy-duty posts that accept only a spade lug, and have solid wing-nuts for tightening. That appeals to me on both counts: I prefer spade lugs for the secure connection, and the wing-nuts make it very easy to get things tight. The models, or targets, for the design of the binding posts were Boulder and Pass, neither of which is in the same general price range.

Finally, the M300s allow for either single-ended or balanced connections. I used single ended, as that fits my system. The RCA connectors are from Cardas and as solid as one would expect. I did not have the opportunity to audition the balanced side but do not doubt the quality.

IQ's high standards for the M300s were not limited to the component parts. Bruce Weisberg, one of the two founders of iQ Audio, said that they wanted to build an efficient, compact and affordable amplifier that could have some of the musical characteristics of Spectral and Pass Labs at the high end.

A look at the iQ web site will show how much the desire to have a stable and powerful amplifier in the real world was a major goal for the M300s. There is a healthy amount of discussion of power ratings and what they mean for the consumer. IQ did a lot of testing in the development of the M300 to ensure that the amps could work with difficult loads. While the power ratings specify what they can do at 8 and 4 ohms, the testing involved loads down to 2 ohms, into Quads, Martin-Logans, Magnepans and more. The FTC tests are not easy for Class D amplifiers but the M300s passed quite well, with an FTC power rating at 4 ohms that doubles the 8 ohm specification.

Class D amplifiers measure very well in many characteristics and the iQ is no exception. The extremely fast switch mode power supply refreshes every 1/100,000^th of a second. Such a power supply can be both quiet and powerful if well made, as well as very reliable. The proof of the pudding is indeed in the eating: the M300s run very quietly, and are quite clean and refined, without gobbling up tons of power.

A Little Listening
I had not had great success listening to earlier Class D amplifiers. While I admired what they could do from their small packages, the musical results were never really convincing. With this prejudice built in, I decided to listen in what I can only call a very unfair fashion. After a brief time getting accustomed to the overall sound of the M300s but without listening too "hard", I selected a number of recordings that I know well. For each, I listened to the M300s first and then to my own amplifier, the Music Reference RM9 MkII, a very fine tube amp that has fared well next to some other excellent equipment in my home. Then to the RM9 again and at least once more to the M300s.

The RM9 is worlds away from the IQ amps in design, execution, weight, size. . . you name it. And it is not a solid-state unit like those that iQ used to voice the M300s. But it is a very good and fairly neutral amplifier that does a good job on all genres of music, from any source, be it analog or digital.

So unfair it may have been, but here goes. Please note that most of my listening was done with my brand-new VPI Classic 3 turntable (more later, but it is quite wonderful). I did also listen to digital recordings via my usual Squeezebox/Wyred 4 Sound setup.

Steamin' with the Miles Davis Quintet (Acoustic Sounds reissue). I started with the RM-9. Everything was crisp, clear, and round with all kinds of precision: the trumpet notes with the mute are sharp and fluid, both piercing and smooth, The bass is very solid and has lots of ambiance. One can hear both depth and a solid center image – the sax is rich and upfront. With the same recording, the IQs were a pleasant surprise. Overall, they were just as quiet as my RM-9. I noted right off the bat that they were more delicate and more reserved. Though a bit reedier than the RM-9, the difference was not huge. The bass notes very firm and tight' they did not lack force or impact.

I heard great left to right placement, wherein the instruments were all terribly precise in placement. It was almost too good. After reviewing for years, one becomes wary of such great images or rendition; it is nonetheless a hallmark of accurate reproduction. Depth was pretty good albeit not up to the laser-sharp lateral placement. Drums were quite clearly behind everything else across a palpable soundstage. Overall, the M300s might not have been quite as "round" or seductive as the RM-9 on the muted trumpet notes, but they held the musical line very nicely. In sum, they were a pleasure to listen to. The M300s excelled in jazz. The sax comes in just as prominently as via my tubes, maybe a little more so. In combination with the lateral precision, the instruments were placed perfectly. My notes used the term "uncanny" and that is not far from spot on. With terrific spatial coherence and truly fine temporal control, the bass does more than nicely with the M300s. My first impression was that this was something I had not heard before.

I then listened to a great album that came to me courtesy of a friend. "The Great Ray Charles" a Rhino re-release of Atlantic 1259, gives us Ray on piano alone. No lyrics; just Ray Charles playing piano. The first cut, Doodlin', is typical, which is to say beyond good.

It is most pleasing that the amps fill the silent part of the space as well as anything I heard. Possibly, there is slightly greater precision in the harmonic structure of a given tone via the tube amp than with the iQ. Though entirely different amps, they share a certain measure (a quality I find admirable).  Overall, my sense is that the harmonics of the tubes are more complete, even if in the bargain, there may be less "rigor" in the bottom end.

I listened to what is now an audiophile warhorse – Rickie Lee Jones' debut album. Via the iQ monoblocks, there was a good flow of the musical line that allowed for some unplanned toe-tapping. Though I am not a "PRAT" fanatic, I do value the ability of any component to follow the music, which often becomes an issue only when it is lacking. The M300s were clean, clear and still musical. I questioned whether or not they were a bit light on the bottom. Or were they just lacking in an extra weight in the bass? It was close enough that I couldn't tell straight away.

On the Rickie Lee Jones via the RM-9s, her voice is fuller and more lifelike. The progression and musical line are very good, with more continuity. Even the quiet sections are just a little more palpable. They pass a corollary of the open-window test – even at a remove, one knows that these recordings are being rendered very closely to the original.

While my RM-9 had generally "won" the comparisons up to now, I sensed that the strong point of the M300s – their precision and clarity – might shine with certain types of music. I had not listened to anything but jazz and classical to that point. A perusal of my LP collection led me to the Sundazed reissue of the Byrds' "Mr. Tambourine Man". The recoding is fine if a little thin, and the pressing pretty good. I had suspected that the iQs might shine and I put "Feel a Whole Lot Better" on my new VPI Classic 3.

And shine they did. There was clarity and separation in a recording with a compact space (some might say congested?). This is still a nice pressing of one of (IMHO) the most perfect pop-rock songs ever made. The iQs did everything right. With clean separation of the spaces between the instruments, and no congestion at all, they carried the tune, and could be played way louder!! The M300s fairly excelled. Only in the guitar solo did my RM-9 sound better, and not by much.

Conclusion
The iQ M300 amplifiers do a great job in every major regard. I am fortunate to live in a city where there is live music everywhere every day. I get to hear a lot of music in real time and real space. The M300s do a convincing job on recordings (jazz, classical) where the music is unamplified and played in a "real" space. One could always wish for more of the sweet, liquid sound of tubes but the M300s go a long way toward emulating the sound of their solid state role models such as Spectral and Pass.

With amplified music, they are superb, thanks to inherent musicality, a very quiet background, and a clear delineation of the soundstage that helps to overcome the crowding typical of so much popular music.  Along with tremendous power, a robust build, and ease of operation, it is hard to see why music lovers would not be attracted to these amplifiers. They are a great value in the under-$2500 segment and worth a careful audition. On that note, since iQ is a direct seller, there is a 30-day free trial period, which means you will have at the very least a month of very fine music.

Manufacturer Reply
We would like to thank Rick Jensen and the staff of Enjoy the Music.com for a thoughtful and thorough review of the IQ M300 monoblock amplifiers. We are quite pleased that the review confirmed many of our design goals, namely that the M300 is a very musical amplifier, coupled with precise inner detail and articulation, with an expansive and precise soundstage. These virtues have been confirmed by customers who have used the M300 with a diverse range of speakers: from planars like Magnepans & Quads, to dynamic speakers such as Vandersteen, Goldenear, Kef, B & W, Klipsch, etc.

We at IQ wish your readers many hours of good listening.

Best regards,

Bruce Weisberg
IQ Audio Corp

Specifications
Type: Solid-state monophonic power amplifier
Power Output: 150 Watt @ 8 Ohms, 300 Watt @ 4 Ohms
Frequency Response: 5 Hz to 45 kHz (– 3dB)
Analog Input Impedance: Balanced (XLR) – 100 kOhms, unbalanced (RCA) – 100K Ohms
Features: 12V trigger and 12V pass through
Dimensions: 3.25" x 7.75" x 7.75 (HxWxD)
Weight: 7 lbs.
Price: $1495 per pair

Company Information
iQ Audio Corp

Voice: (818) 481-8522
E-mail: sales@iqaudiocorp.com
Website: www.iqaudiocorp.com