[Trysaeder]

So I got my dad to buy me an M^3 kit because I wanted to built something and didn't see the $25 kit thread.

Anyway I've heard this amp is technically pretty good, but I'm only going to be using AD700s with them.

I'll be getting another pair of headphones soon, probably something with a similar sounds signature to the AD700. I was looking mostly at the K701, but I wanted to know what other headphones the M^3 can drive to a good standard.

 

[nikongod]

There are few headphones the M3 cant drive well.

 

[Superpredator]

I haven't heard the M^3 choke on any headphones yet--yet neither would I say it has mind-blowing synergy with any one model or manufacturer. Very, very good with AT, AKG, Beyer, not my favorite with Grado or Senn. Of course, being DIY, variations in op-amp and power supply could translate to yours not sounding like mine. Either way, I'd expect it to make the AD700 sound quite nice.

Edit: Even though it doesn't see much use these days, I keep the M^3 around as a capable, dependable backup in case I'm ever in a pinch.

 

[Trysaeder]

What about IEMs? Is it safe to plug them in but just turn down the sound?

 

[Uncle Erik]

Pretty much anything aside from the K-1000.

 

[Superpredator]

Quote:

Originally Posted by Trysaeder /img/forum/go_quote.gif What about IEMs? Is it safe to plug them in but just turn down the sound?

I don't remember. Probably depends on your M^3's configuration and the sensitivity of the IEMs in question. Safe, but the background noise (humming, etc.) might be intolerable. I may have tried it once or twice using a UM2 but because they have such a short cord it wasn't worth caring about either way. I might be setting all my equipment up shortly; if I do I'll let you know how they fare.

 

[nikongod]

Quote:

Originally Posted by Uncle Erik /img/forum/go_quote.gif Pretty much anything aside from the K-1000.

Why?

Everyone says the K1000 needs a speaker amp and cant use a headphone amp, but the M^3 has been seen running speakers. Id try it.

 

[Shahrose]

Quote:

Originally Posted by Superpredator /img/forum/go_quote.gif I haven't heard the M^3 choke on any headphones yet--yet neither would I say it has mind-blowing synergy with any one model or manufacturer. Very, very good with AT, AKG, Beyer, not my favorite with Grado or Senn. Of course, being DIY, variations in op-amp and power supply could translate to yours not sounding like mine.

As you said, it depends on the opamps and maybe the build. I think they have excellent synergy with Senns, and pretty much every headphone I've tried tbh.

Quote:

Originally Posted by Uncle Erik /img/forum/go_quote.gif Pretty much anything aside from the K-1000.

That's incorrect sir, see below.

Quote:

Originally Posted by nikongod /img/forum/go_quote.gif Why? Everyone says the K1000 needs a speaker amp and cant use a headphone amp, but the M^3 has been seen running speakers. Id try it.

x2...Here's the math to prove it. Taken from a post by Morsel (M^3's co-designer).

Each M³ output has 1 set of 18A IRFZ24N & IRF9Z34N MOSFETs and 1 Ohm source resistors. The low output impedance before feedback and resulting damping factor will be more than enough to tightly control the most intransigent load. The figures below clearly confirm the capability to drive these headphones to ear splitting levels.

Please feel free to Review The Fine Numbers:

AKG K1000 Efficiency = 74dB SPL/mW. Impedance = 120 Ohms.

For 90dB SPL, 2.2Vrms (6.2Vpp) pushes 18mA to deliver 40mW of power.
For 100dB SPL, 7Vrms (20Vpp) pushes 58mA to deliver 400mW of power.
For 104dB SPL, 11Vrms (30Vpp) pushes 91mA to deliver 1W of power.

(1W is the maximum input power of the K1000)

AKG K340 Efficiency = 94dB SPL/mW. Impedance = 400 Ohms.

For 94dB SPL, .63Vrms (1.78Vpp) pushes 1.57mA to deliver 1mW of power.
For 104dB SPL, 2Vrms (5.65Vpp) pushes 5mA to deliver 10mW of power.
For 117dB SPL, 9Vrms (25.5Vpp) pushes 22.5mA to deliver 200mW of power.

(200mW is the maximum input power of the K340)

Beyerdynamic DT990 Efficiency = 96dB SPL/mW. Impedance = 600 Ohms.

For 96dB SPL, .77Vrms (2.2Vpp) pushes 1.3mA to deliver 1mW of power.
For 106dB SPL, 2.5Vrms (7Vpp) pushes 4mA to deliver 10mW of power.
For 115dB SPL, 7Vrms (19.8Vpp) pushes 11.6mA to deliver 80mW of power.

(80mW is the maximum input power of the DT990 600 Ohm model)

 

[zzffnn]

I have used M3 with Westone ES3Xs, Beyer T1, AKG K400s and LCD-2s. The M3 drives all three cans easily; my volume pot has never passed 12 o'clock even with gain at 2X (never passed 10:30 o'clock with gain 6, I can choose as my M3 has adjustable gain). At gain 2X, the M3 drives Westone ES3Xs without any hiss or noise. Sound quality is very good too, very transparent and detailed.
 
I agree with Shahrose. I read elsewhere that M3 can drive AKG K1000s and K340s to very load volume as well.
 
Edit: Westone ES3Xs are IEMs with very high sensitivity (124 db/mw) and will hiss badly when paired with a noisy amp, not the case with M3 at gain 2X though.