Reviews of M^3 amplifier ?
Feb 2, 2010 at 2:32 PM
Quote:

 Originally Posted by Beefy /img/forum/go_quote.gif About half that, actually. At the default 24V and 80mA quiescent current per channel, total current draw is approx 300mA - 7.2 watts.

Well just to point out your math is just for the power draw of the M3 itself, the s11 is far from 100% efficient so the power draw total is going to be a good bit more than 7.2 watts.

Feb 2, 2010 at 2:51 PM
Quote:

 Originally Posted by m1abrams /img/forum/go_quote.gif Well just to point out your math is just for the power draw of the M3 itself, the s11 is far from 100% efficient so the power draw total is going to be a good bit more than 7.2 watts.

Say an S11 is dropping 10V to regulate (well above the recommended 7V) and running at 300mA...... that is still only approx 3 watts

Feb 2, 2010 at 2:55 PM
Quote:

 Originally Posted by Beefy /img/forum/go_quote.gif Say an S11 is dropping 10V to regulate (well above the recommended 7V) and running at 300mA...... that is still only approx 3 watts

And the transformer loss
We are getting close to his 15 watts, and we do not know how he measured it or if he is using a 24V supply and only 80mA bias.

Feb 2, 2010 at 3:14 PM
Quote:

 Originally Posted by Beefy /img/forum/go_quote.gif My point was a round-about way of saying I don't think he actually measured it......

maybe not but I think actually usage is closer to 15watts than 7.2watts. Not accounting for transformer loss which is probably about 85% efficient you have calculated 10.2 watts add in the transformer loss you get ~12 watts total.

Feb 2, 2010 at 3:52 PM
Quote:

 Originally Posted by Magsy /img/forum/go_quote.gif My Mcubed was always warm and bassy but I like it that way. I had AD843 opamps for maximum (softer) bass. I think the advantage you have with this amp is you can swap the opamps and hopefully find what you require. I changed my source and it became too bassy so I put OPA627's in and the balance was restored. I always hated the AD8610's but they might be the sort of thing you'd want, a bit leaner and lighter. The Beta 22 is faster, lighter and more punchy but cooler sounding. I had the Mcubed since release and even now with a balanced Beta 22 in the house I find it very good, it is not that far away.

Quote:

 Originally Posted by johnwmclean /img/forum/go_quote.gif x1 This is exactly the same impression I found between the two amps, also with OPA627s.

Great impressions...and just what I would expect when compared to an M^3 with those opamps. The AD843 warm the sound and emphasize but slow the bass as well (not as much as the OPA637) with a smaller soundstage than the OPAs and treble characteristics somewhere in between the OPAs and the AD.

At the risk of sounding like a broken record, I'll say that if the default AD8610 opamps are used (ones AMB recommends and tests with for 24V), the sound signatures would be a lot closer to the Beta based on what's being described here. I would be interested in someone trying this out. Almost every comparison I've seen of an M^3 with something has been with different opamps in the M^3 and this has resulted in impressions scattered across the board.

Feb 2, 2010 at 5:15 PM
I built matching m³, one with 637/627, and the other with ad8610. With the Senn 6x0, I preferred 637/627 by quite a wide margin, but dumped both for tubes. That was the point at which I discovered SS is just not my scene.

Feb 2, 2010 at 5:56 PM
Quote:

 Originally Posted by Shahrose /img/forum/go_quote.gif Great impressions...and just what I would expect when compared to an M^3 with those opamps. The AD843 warm the sound and emphasize but slow the bass as well (not as much as the OPA637/627) with a smaller soundstage than the OPAs and treble characteristics somewhere in between the OPAs and the AD. At the risk of sounding like a broken record, I'll say that if the default AD8610 opamps are used (ones AMB recommends and tests with for 24V), the sound signatures would be a lot closer to the Beta based on what's being described here. I would be interested in someone trying this out. Almost every comparison I've seen of an M^3 with something has been with different opamps in the M^3 and this has resulted in impressions scattered across the board.

i'll throw some AD8610 in with my Digikey order this week.

Feb 2, 2010 at 6:18 PM
Quote:

 Originally Posted by Beefy /img/forum/go_quote.gif My point was a round-about way of saying I don't think he actually measured it......

Take it up with the Kill A Watt meter. I also measured the G2/s11 and it sits right at 6 watts all the time. So for 21 watts I get a killer headphone setup, I think that's a pretty good trade.

I spent some time researching alternative energy some years ago and bought a Kill A Watt meter to understand what the solar people were talking about. Amazing how many current sucking vampire devices there are in your home like clock radios that are constant loads. It makes a huge difference when you run off batteries and converters.

Feb 2, 2010 at 6:29 PM
Quote:

 Originally Posted by fishski13 /img/forum/go_quote.gif i'll throw some AD8610 in with my Digikey order this week.

You know I have both AD8610 and OPA627 opamps for my M3. I have swapped them a few times and really could not hear much of a difference to be honest. Course it is really hard to compare the two since switching is not a quick task. Also when I compared them that was with my Grado SR225 which may make it harder to hear subtle differences. I might try the swap again with my K702s see if I hear any difference. I would not expect a whole heck of a lot of change though, I think sometimes people tend to make things sound much more drastic in writing than they exist in real life.

Feb 2, 2010 at 6:36 PM
I actually dropped the electric bill by using power strips with switches on stuff like computers and entertainment systems and leaving them turned off when not in use. Refrigerators suck it down but small chest freezers are extremely efficient.

Central A/C is a beast you can't really do anything about and that's why I am always concerned about heat with electronics. I sit in an 8x8 room all day with 3 monitors and a computer radiating a pretty constant 180 watts. Needless to say a 100 pound class A speaker amp idling at 200 watts isn't in my future. Yet another reason I think the M3 is a great amp....it's straight up Class A without the heat.

Feb 2, 2010 at 7:36 PM
Quote:

 Originally Posted by CodeToad /img/forum/go_quote.gif Take it up with the Kill A Watt meter. I also measured the G2/s11 and it sits right at 6 watts all the time. So for 21 watts I get a killer headphone setup, I think that's a pretty good trade.

That's good to know. It's something I'm also taking into consideration when buying my gadgets. I need to get myself a Kill A Watt meter these days as well. I'm quite curious about the power consumption the different electrical appliances we have at home.

Feb 2, 2010 at 7:38 PM
Quote:

 Originally Posted by m1abrams /img/forum/go_quote.gif You know I have both AD8610 and OPA627 opamps for my M3. I have swapped them a few times and really could not hear much of a difference to be honest. Course it is really hard to compare the two since switching is not a quick task. Also when I compared them that was with my Grado SR225 which may make it harder to hear subtle differences. I might try the swap again with my K702s see if I hear any difference. I would not expect a whole heck of a lot of change though, I think sometimes people tend to make things sound much more drastic in writing than they exist in real life.

Exactly why I had matching units, side by side, except for the opamps. Same source. Same phones. Same cables.

But note also I was using 637 (big diff) on the signal channels, and 627 on the center channel. It was a clear difference, where I found the ad8610 harsh in the treble, and far colder / sterile / analytical compared to the opa637 (which is what you actually hear). Don't doubt for a moment that the delta between 627 and 8610 is less pronounced, especially with lower end (or any) Grados. I am betting the k701 will be a better test.