IQ Audio M300 MonoBlock Amplifier Review

Discussion in 'Amps, Pre-Pros & Receivers' started by admin, Jan 30, 2014.

  1. admin Audioholics Robot Staff Member

    admin
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    When I was presented with the pint sized IQ Audio M300 MonoBlock amplifier for review, I wanted to pick it apart as nothing more than a gimmick. Instead I was pleasantly surprised. The M300 is the first Class D amplifier that I'd seriously consider for my own use. It offers better measurable performance than I've seen from any other Class D designs, generates little to no heat making it ideal for stacking multiple units or cramming into tight spaces. Most importantly, the M300 sounds fabulous, never misbehaving or losing composure. Deceptively good is how I'd best describe this amplifier. It has me wondering, what's next for IQ Audio?
    [​IMG]

    Read the IQ Audio M300 MonoBlock Amplfier Review

    Would you buy a Class D amp? What about this little gem? Let us know.
    Last edited by a moderator: Jan 30, 2014
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  2. greatdavide Audioholic Intern

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    Well we all knew it was possible but it's awesome to see a truly kick *** Class D design. I hope these guys make it or at the least that their tech gets bought by a big player and we see a lot more products along this line, especially 2 channel and 7 channel versions! But seriously I love routing for the little guy with the kick *** tech, I hope they clean house with these, I have an Aperion system that I'd love to play a little louder. On a side note didn't Axiom redesign their amps? Have you tested their new design or will you soon? I know they had... some issues last time. You guys still on speaking terms?
  3. ImcLoud Audioholic Ninja

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    interesting, I would like to see 300w at 8 for that price, but still good idea, also I hate seeing phillips screws on gear, another 8 cents for recessed allens...
    I do like the look, xlrs, and speaker terminals... very cool.
  4. RichB Audioholic General

    RichB
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    Great review.

    This is an impressive little amp. Is this a startup, they appear to have only this product?

    - Rich
  5. TheoN Audioholics Contributing Writer

    TheoN
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    Gene,

    Wow. The power/size ratio of these things is just amazing. There's some exciting potential in the years ahead.
  6. jinjuku Moderator

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    So outside of the obvious efficiency = no 'head room' was there other legitimate concerns / items you saw with this amp?

    Class D isn't going to have that margin where the old, in-efficient, A/AB designs could get efficient for a split second and deliver a wallop of power outside their measured spec.

    The solution to that is getting a Class D that is simply rated higher in terms of over all output. There should be no difference ,as a stress level, of a Class D that can output a reliable 1kw and a 300WPC A/AB that can get there in a cycle or two when needed.
  7. RichB Audioholic General

    RichB
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    ^^^

    So is this a correct statement:

    When buying class-D versus A/B, you cannot rely on extra margin for use with a stressed system, therefore, buy more power class-D powre to make sure there is sufficient headroom?

    - Rich
  8. jinjuku Moderator

    jinjuku
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    Say you have a sub that is RMS 400 Watts and Peak 1100. Good chance that with a Class AB amp that does 400 WPC at the impedance of speaker that it could hit clean peaks of 800-1000 watts.

    Since a Class D is so efficient it wears it's #'s more on the shirt sleeve than heater designs do. So with a driver that can handle 1100 watt peaks you would get a 900 WPC RMS Class D that would match up.
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  9. greatdavide Audioholic Intern

    greatdavide
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    I've never though of this before but it raises a lot of questions for me.
    Can Class A/B amps hit that peak power across the frequency range? Or will you still see clipping at certain frequencies? And do you even need the headroom since the class D won't clip? How often do you have non repetitive momentary peaks to that extreme in a source material (2X-2.5X)?
  10. surveyor Audioholic Chief

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    Nice Amp

    Thanks for the excellent review!:)
  11. RichB Audioholic General

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    That is 3 to 5 DB. Not that hard in well record music.
    Of course, at that point the volume turned up.

    - Rich
  12. haraldo Audioholic Spartan

    haraldo
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    Thx Gene for a great review (as always)

    You write:
    At 4 ohms, I measured a whopping 371 watts (1% THD+N) and 317 watts (1% THD+N).

    Do you mean?
    At 4 ohms, I measured a whopping 371 watts (1% THD+N) and 317 watts (0.1% THD+N).
  13. cutedaddy Enthusiast

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    "Class D come of age"?!!

    No one ever heard of Bruno Putzeys' 'Universal Class D' before? That's when class D came of age, over ten years ago if i'm not mistaken. Since, Putzeys has improved his class-D circuit so often and so much, that there really is no class-D in existence to beat it, or any other class for that matter. Putzeys' NCore units need the invention of new measurement gear, for their distortion, hiss, hum and what have you are unmeasurable. When opened at full power, 700W into 2Ω, with a source connected but not playing, this is what you hear: nothing at all. Nothing, total silence at 1cm from the speaker driver. Please feature a comparative on several top-class D amps, including the Hypex NCore of Putzeys asap.
  14. haraldo Audioholic Spartan

    haraldo
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    I wonder if Bruno is overly confident, is this the revolution he claims....????

    This is what Dusty Wavter at Channel Islands Audio say about ncore:
    We have built a few prototypes using the NCORE technology and they are very similar to the standard modules but with a few upgrades.
    The main improvement is the efficiency of the on-board gate drive circuit. We don't use the on-board circuit and have had our own for a couple of years now (MKII versions and D-100B). On our D-500 MKII, we use a custom module in full bridge configuration that we feel is better than any of the high power DIY models and are working on a full bridge stereo amplifier which uses the 250LP module (with NCORE gate drive circuit).
    The NCORE models are great for the DIYer, but don't get caught up in their marketing hype, it's not a "revelation" just has some improvements/refinements.
    We use primarily the output section & modulator of the stock module, everything else is done in-house.

    They push these with their switching power supplies (which we have tested) and they do not compare to our linear supplies with individual windings for each part of the amplifier circuit.

    There are some really well performing class-d contenders out there: Devialet, nuforce, CI Audio, Lyngdorf, Steinway Lyngdorf and probably many more.... to say that Bruno killed all competition is a bit of an exaggeration if you ask me.... (it's my opinion only though)
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  15. jinjuku Moderator

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    I've never heard a bad thing about the NCore but he's hardly only and first. Carver, Crown all have PWM and SMPS patents dating back almost 30 years. Crown has something like 17-20 patents just for PWM/SMPS alone.
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  16. greatdavide Audioholic Intern

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    I thought about this some more and feel like I'm missing something here.

    I thought most subs used class D (I'm fairly ignorant so I may be completely wrong). They still state power at peak and RMS. What does that mean then?
    For instance, here is the power rating for the class D amp in paradigms sub 12:
    Prodigious total output: 3,400 watts of Dynamic Peak Power; 1,700 watts (850 watts each amplifier) of RMS Sustained Power.
    How is this possible with class D if they have no headroom? It makes sense that Class D would not have headroom but then what are these guys claiming?

    I would love to see the education pages expanded, I read the amp class article and the class D article and while helpful I still feel pretty unsure on Class D amps.

    To be fair Paradigm refers to these as "ultra-class-D" amps ;)
    ref:
    Paradigm® | Subwoofer | SUB 12 | Overview
    Last edited by a moderator: Oct 19, 2014
  17. greatdavide Audioholic Intern

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    Class D amp shootout

    I'm also with the guys above thinking it would be really great to see a bunch of reviews of this amp class and an overview of the differences to compare what everyone doing. For instance Axiom redesigned their class D and the other brands mentioned earlier would all be interesting.:cool:
  18. conanb Audiophyte

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    Audioholics should review one of the D-Sonic class D amps.
  19. gene Audioholics Master Chief Administrator

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    Yes, let me fix that. Thanks.
    gene,
  20. cutedaddy Enthusiast

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    @jinjuku and @haraldo

    Thanks for your replies, i am honored.

    Whether Hypex's UcD and NCore modules are overhyped i wouldn't know. That's why i would like to see a Class-D comparative testing article, really putting the measurements in perspective, on a nice comparative spreadsheet. Relevant measurements that is, but we can leave that to Gene, or someone else serious about testing.

    As far as i can find, there are no serious (meaning "objective") reviews that doubt the claims Hypex is making about it's own modules, but, on the contrary, several that confirm the stated claims. In other words, Putzeys is NOT overconfident as far as i can judge.

    Sure there's more class-D contenders, and sure class-D existed before Putzeys. Carver e.a. are great contributors to audio development. However, the UcD module originally patented by Philips was patented because it was a leap forward. Since, Putzeys has left Philips to join Hypex and has registered a whole number of new patents making even the Philips UcD obsolete by comparison. So yeah, Putzeys is a step ahead IMO.

    About Channel Islands Audio: they have a lot to say about Bruno's modules, but the bottom line in my view is: they are USING THESE MODULES for their own products. Why? I'll tell you three good reasons why: 1. The modules are so good; 2. The modules carry a patent CIA would like to own, but they don't; 3. The modules are very competitively priced. So much so, CIA can make a huge profit. Of course they will have to uphold that they do a lot 'in house', or else what would be the justification of their pricing?

    To me, Channel Islands Audio are too much involved to give any objective comment on the NCore. If it's nothing at all, why do they use it in the first place? If it's not a bother to do all these 'upgrades' in house, why don't they do their complete amplifier in house, but use Hypex modules instead? They don't have the right to speak AFAIC, i have yet to see ABX-tested any accomplishment completely their own.

    The Hypex modules measure unrivaled and do very well in blind listening trials as well. Output impedance (=cone control)? Industry lowest. Completely discreet signal path, no IC's, who else has that? Regulators measure unrivaled as well. Gain structure, I/O buffering, plenty other features no one else handles so well. Please show me wrong, always curious to learn more.

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