Motu M2 Review (Audio Interface)

[umbral]

For those interested, I've seen the insides of the M2 and M4. All the specs below are identical in both the M2 and M4. The ADC in the M4 is the same chip but supports 4 preamps instead of 2.


M2 & M4 chips:

• ADC - AK5552VN (AK5554VN in M4)
• DAC - ES9016S
• Integrated Circuit - XMOS U11680C20
• Headphone Amp - OPA1688 (50mW @ 32Ω, 3.3Vrms)
• Mic Preamp: THAT 6263

Very interesting.

The current top AKM is AK5572EN / AK5574EN / AK5576EN / AK5578EN
That has THD+N -112 db vs -106 db on Motu M2/M4 and 121 S/N vs 115 on Motu M2/M4

https://www.akm.com/eu/en/products/audio/audio-adc/

The headphone amp is from early 2016 / December 2015, quite good - can't find better in other buget audio interfaces, but needs low ohm headphones like AKG K371 because of USB power only.

The OPA1688 and OPA1689 are a family of SoundPlus™ 36-V, single-supply, low-noise operational amplifiers capable of operating on supplies ranging from 4.5 V (±2.25 V) to 36 V (±18 V). This latest addition of high-voltage audio operational amplifiers, in conjunction with the OPA16xx devices provide a family of bandwidth, noise, and power options to meet the needs of a wide variety of applications. The OPA168x are available in micropackages, and offer low offset, drift, and quiescent current. These devices also offer wide bandwidth, fast slew rate, and high output current drive capability. The dual and quad versions all have identical specifications for maximum design flexibility.

Unlike most op amps that are specified at only one supply voltage, the OPA168x family is specified from 4.5 V to 36 V. Input signals beyond the supply rails do not cause phase reversal. The input can operate 100 mV below the negative rail and within 2 V of the top rail during normal operation. Note that these devices can operate with full rail-to-rail input 100 mV beyond the top rail, but with reduced performance within 2 V of the top rail.

The OPA168x series of op amps are specified from –40°C to 85°C.

Mic Preamp: THAT 6263
http://www.thatcorp.com/626x_Dual_Programmable_Preamp_ICs.shtml

Also good.

 

[Longshan]

Does anyone know if the software offers a low cut filter?

If you're talking about MOTU software for the M2, then no.

 

[txbdan]

You would need a MOTU with built in DSP like the 624, etc. They have a DSP mixer with EQ, effects, etc. It's pretty darn slick.

 

[Chromatischism]

Thanks. I ended up getting a USB mic with a low cut switch so all of this is moot now for many reasons

 

[umbral]

Thanks. I ended up getting a USB mic with a low cut switch so all of this is moot now for many reasons

What USB model did you get ?

You can add low pass filter in DAW, you do not need it on the microphone itself. Same with high pass filter or any other filter.

 

[Chromatischism]

What USB model did you get ?

You can add low pass filter in DAW, you do not need it on the microphone itself. Same with high pass filter or any other filter.

Rode VideoMic NTG

 

[Chromatischism]

I have the M4, which has a few more inputs/outputs and some extra monitoring features. I vastly prefer it to the multi box situation I had before, for controlling headphones and monitors at a computer. I have the monitor outs connected to powered monitors and keep my headphones plugged in. I control which one I listen to by using the separate volume controls.

This functionality, combined with the immense convenience of the additional inputs/outputs/beautiful meters/super low latency has sworn me off so called audiophile dacs/headphone amps. If you want to get audio into or out of a computer this is probably the best way to do it for most people.

Also I like that they design these things in my backyard in Harvard Square.

Without an optical input, you're required to connect it via USB which makes it prone to picking up computer noise. You must not have an issue otherwise you'd have mentioned it, but I'd like to know if the M2 completely filters this out. That is the only way I would consider a USB DAC.

 

[jonljacobi]

I’ve only had issues with USB once. A shunt cured it completely.

 

[MNMLSM]

Living in Germany and trying to order the M2 since April, no chance.
Order status is "available in 8-10 weeks". Is it sold out all over the world?
Any hardware changes regarding the restock units? I hope the order status is correct this time, I am sceptical.

 

[Evgeniy]

Anyone tested, Motu M2 version 2 (with new USB chip) works with Android USB audio recorder pro ?

 

[Chromatischism]

Anyone tested, Motu M2 version 2 (with new USB chip) works with Android USB audio recorder pro ?

How do you identify this when shopping?

 

[umbral]

Got a new Motu M2, plugged in AKG K-371 there is a lot of hiss on all music via headphones, youtube or mp3 or flac.

What is the problem ? Defective headphone amps ?

Did anyone encountered this issue ?

The headphones AKG K371 are working perfect with the PC motherboard high quality audio chip for youtube mp3 or flac.

Regardless of where i put the volume on the Motu M2 you can hear hiss and distortion.

 

[phoenixsong]

Got a new Motu M2, plugged in AKG K-371 there is a lot of hiss on all music via headphones, youtube or mp3 or flac.

What is the problem ? Defective headphone amps ?

Did anyone encountered this issue ?

The headphones AKG K371 are working perfect with the PC motherboard high quality audio chip for youtube mp3 or flac.

Regardless of where i put the volume on the Motu M2 you can hear hiss and distortion.

That's strange, mine's pretty much dead silent on my different IEMs at loud enough listening levels. Used Windows media player and YouTube and Groove music with the native APO as well as Equalizer APO. Windows 10 pro laptop, tried both USB and Thunderbolt ports

 

[B-Flow]

Has anyone who has one of these upgraded to Windows 11 yet? Just wondering if the W10 software/driver works ok.

 

[andrewskaterrr]

Has anyone who has one of these upgraded to Windows 11 yet? Just wondering if the W10 software/driver works ok.

I suggest not upgrading to Windows 11 for the time being, but I'm guessing you already have?

 

[B-Flow]

I suggest not upgrading to Windows 11 for the time being, but I'm guessing you already have?

Are you saying that because you know the M2 has issues, or you just dont like Windows 11? Yes I'm running it allready and its fine. I was able to try a 2i2 and it works perfectly.

 

[andrewskaterrr]

Are you saying that because you know the M2 has issues, or you just dont like Windows 11? Yes I'm running it allready and its fine. I was able to try a 2i2 and it works perfectly.

Because if you hadn’t upgraded yet, I would’ve told you to wait and ensure it works with 11 before upgrading. In your case you’re already on 11, so you should still hold off until someone else takes the leap.

 

[Backflash]

I've read through whole "IMD hump" conversation. I still do not understand, what does it mean in practical terms? Is any of it audible?

M2 balanced (albeit probably not TRUE balanced) output is very nice for some up in power.

Also what does that mean? By "true" balanced you mean DAC per channel?

 

[Blumlein 88]

Q. How is impedance balancing audio different from normal balancing?

Would impedance balanced and electronic balanced audio provide exactly the same noise reduction as regular symmetrical...

www.soundonsound.com

Look at impedance balanced in the above article. Many/most lower priced interfaces (and some not so low priced) are made this way. And despite what you might think it works fine.

Here is another perhaps better explanation.

Impedance Balanced Output Circuits

 

[Backflash]

Q. How is impedance balancing audio different from normal balancing?

Would impedance balanced and electronic balanced audio provide exactly the same noise reduction as regular symmetrical...

www.soundonsound.com

Look at impedance balanced in the above article. Many/most lower priced interfaces (and some not so low priced) are made this way. And despite what you might think it works fine.

Here is another perhaps better explanation.

Impedance Balanced Output Circuits

Thank you. Neat, from user perspective it's the same thing. Begs the question why isn't everyone making balanced connections on everything this way, due to how many people use better audio hardware for all rounder PC use - it's long overdue to let go of RCA.
250w GPU under load messes with any USB port. Researching the topic I see many people complain about such things.