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Motu M4 Audio Interface Review

137tmxth

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The puzzle is now solved!

The INPUT 1 jack must be a high-impedance instrument-only input, I was using a JACK-JACK cable.

I've tried using the XLR connector, and now you do get a decent response. Not as good as INPUT 3, but it makes sense!

Be careful using INPUT 1 XLR, as line input, because if we press phantom power we can cause a problem.

If you read the manual, I don't think it says anywhere that inputs 1-2 are supposed to be used as line inputs only if using XLR connectors. In fact, it says the exact opposite on page 17:

page17.png

I'd say it's actually more likely that people will want to use phone plugs to connect line level devices than XLR, and the XLR inputs are more likely to be only used for microphones. So phone plug inputs on the combo connectors really should work just as well or better than XLR for line level sources. :(

I'll try some tests on my own unit when I get back home so next weekend at the soonest.

Occasionally I'd love having line inputs with gain that doesn't need to be applied in software and besides the device was always marketed as having 4 instead of 2 line inputs anyway. If there really is some kind of a design error here, I wonder what to do? There's still plenty of the warranty period left in case I'd try to get it exchanged, but are there even any revisions which don't have a problem? I do like the unit otherwise.
 
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isabido

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Si lee el manual , no creo que diga en ninguna parte que se suponga que las entradas 1-2 se usen como entradas de línea solo si se usan conectores XLR. De hecho, dice exactamente lo contrario en la página 17:

View attachment 205400

Diría que en realidad es más probable que la gente quiera usar enchufes de teléfono para conectar dispositivos de nivel de línea que XLR, y es más probable que las entradas XLR solo se usen para micrófonos. Por lo tanto, las entradas de enchufe de teléfono en los conectores combinados realmente deberían funcionar tan bien o mejor que XLR para fuentes de nivel de línea.:(

Haré algunas pruebas en mi propia unidad cuando regrese a casa, así que el próximo fin de semana lo antes posible.

Ocasionalmente, me encantaría tener entradas de línea con ganancia que no necesita ser aplicada en el software y, además, el dispositivo siempre se comercializó con 4 entradas de línea en lugar de 2 de todos modos. Si realmente hay algún tipo de error de diseño aquí, me pregunto qué hacer. Todavía queda mucho del período de garantía en caso de que intente cambiarlo, pero ¿hay alguna revisión que no tenga ningún problema? Me gusta la unidad de lo contrario.
I agree with you, I don't understand why with the TRS connection it has such a bad response, but I think it's because they have it designed for high impedance instruments.

What confuses me is that the fellow @trl has verified it with his MOTU M4 (first version) and measures it PERFECTLY by TRS.

I think this is a problem that affects the latest hardware versions, let's see if we can all draw a conclusion.
 

phoenixsong

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I agree with you, I don't understand why with the TRS connection it has such a bad response, but I think it's because they have it designed for high impedance instruments.

What confuses me is that the fellow @trl has verified it with his MOTU M4 (first version) and measures it PERFECTLY by TRS.

I think this is a problem that affects the latest hardware versions, let's see if we can all draw a conclusion.
Is it due to TS vs TRS? Instruments are usually TS only
 

isabido

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Is it due to TS vs TRS? Instruments are usually TS only
This is also true, it should be when the jack was TS, but in my case it happens with a TRS jack.

The only way to get decent frequency response out of inputs 1/2 is with the XLR connectors.
 

companyja

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Greetings!

I recently got my Motu M4 (v3), and wanted to know if anybody else got the input meters going up showing in the LCD screen after turning the mic pre-amps around 4 o'clock and above without a signal connected. Is this normal behaviour from the interface?

Thanks in Advance!View attachment 204230
Edit: Also, does anybody know if this unit version has enough gain for an SM7B?
The inputs will have gain noise if they're unloaded. As soon as you put an XLR microphone into the jack, that gain noise will disappear. It's normal for the device to be noisy with nothing connected to it
 
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I am the happy owner of a MOTU M4, but would like a little more power for my sundaras. Can you recommend me an amp that will pair well with the MOTU? I also have a rather trivial question, will I be able to control the headphone volume with the big knob on the MOTU when the amp is plugged in? Is this the correct way to control volume with an amp?

I am also wondering if i already have an amp, should i connect it with balanced trs/xlr or rca ? I know this question has been answered in this thread, but I am wondering why RCA would be better than balanced one ?
 
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phoenixsong

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I am the happy owner of a MOTU M4, but would like a little more power for my sundaras. Can you recommend me an amp that will pair well with the MOTU? I also have a rather trivial question, will I be able to control the headphone volume with the big knob on the MOTU when the amp is plugged in? Is this the correct way to control volume with an amp?
The SMSL HO100 that was recently reviewed here is a good budget balanced amp that can be paired with the Motu M series. Yes, you will be able to control volume via the big knob as well as through the amp itself or from your pc
 

spnc

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Greetings!

I recently got my Motu M4 (v3), and wanted to know if anybody else got the input meters going up showing in the LCD screen after turning the mic pre-amps around 4 o'clock and above without a signal connected. Is this normal behaviour from the interface?

Thanks in Advance!View attachment 204230
Edit: Also, does anybody know if this unit version has enough gain for an SM7B?

Hi just curious here, how do you know which version we have? I have two screws per output, is it a 'v2' (it says '2020, 2019' on the print at the back)?

What are the features of the 'v3'?

Is the anyway to find out about the version on a Mac with the firmware?

Cheers.
 

spnc

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Hi guys I'm about to get an amp (JDS Atom) to make the most of my 880 Pro 250 cans with the M4.

1. Total noob question here: which output of the M4 do I need to connect the RCA cable from the M4's RCA input: 'Line Out' or 'Monitors'?

2. Is this guy accurate when saying "the signal from the Motu's RCA out is phase inverted so keep that in mind"? What consequence is this going to have when listening through the Motu RCA > JDS Atom? What does he mean by "out of phase with balanced outs"? The JDS Atom is unbalanced anyway right, so I won't have this problem?


Screenshot 2022-06-24 at 11.23.33.png



Screenshot 2022-06-24 at 11.23.45.png



Cheers.
 

JimmyBuckets

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Travis at Motu was gracious enough to answer my questions. All versions are identical. v1, v2, v3 are in his words different production runs.
 

JimmyBuckets

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Hi guys I'm about to get an amp (JDS Atom) to make the most of my 880 Pro 250 cans with the M4.

1. Total noob question here: which output of the M4 do I need to connect the RCA cable from the M4's RCA input: 'Line Out' or 'Monitors'?

2. Is this guy accurate when saying "the signal from the Motu's RCA out is phase inverted so keep that in mind"? What consequence is this going to have when listening through the Motu RCA > JDS Atom? What does he mean by "out of phase with balanced outs"? The JDS Atom is unbalanced anyway right, so I won't have this problem?


View attachment 214380


View attachment 214381


Cheers.
Line outs for listening. For listening there is no need to worry about phase inversion...this would only effect you if you were making measurements using the M4. :)
 

agent_x007

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Travis at Motu was gracious enough to answer my questions. All versions are identical. v1, v2, v3 are in his words different production runs.
Right...
Actually there are three versions.
v1 XMOS controller+ES9016S DAC+AK5554 ADC
v2 NXP controller+ES9026pro DAC+AK5554 ADC
v3 Atmel controller+ES9026pro DAC+ES9840 ADC
v2&v3 both have 2.xx firmware:)
index.php
index.php
View attachment 191711
To answer previous question : Both v2s and v3s have two screws [top left + bottom right], on each XLR port (vs. one [top left] on v1).
Only way to be sure which version you have (v2 vs. v3) is pulling PCB out and checking ICs (as both v2 and v3 use the same firmware).
 

MCH

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Right...

To answer previous question : Both v2s and v3s have two screws [top left + bottom right], on each XLR port (vs. one [top left] on v1).
Only way to be sure which version you have (v2 vs. v3) is pulling PCB out and checking ICs (as both v2 and v3 use the same firmware).
Has anyone figured out if v.2 and 3, with different dac chips, still have the imd hump amir measured in v1?
 

spnc

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Line outs for listening. For listening there is no need to worry about phase inversion...this would only effect you if you were making measurements using the M4. :)

Thanks a bunch :)

I ended up getting the Lake People G103-S MKII (second generation released last december - www.lake-people.de/en/categories/headphone-preamps/lake-people-g103-s-mkii) instead of the JDS Atom because I don't wanna wait for the shipment from the US. It's a shame JDS solely sells its product from their US website and nowhere else, they seem to have a great customer support, but shipping times + shipping fees + VAT cost (I'm in Switzerland so not EU, they're gonna charge upon arrival...) is just a turn off.

Lake People is a very solid brand from Germany and a producer friend of mine was using the MKI, I hope I didn't make a mistake ^^ they look pretty similar as the -S version is unbalanced. Built like a tank. And in my experience anything built in Germany usually is superior (not referring to WW2 here, haha okay bad joke).

1656099611932.png


for anyone interested fyi there's also a -P version for 50 bucks extra with balanced ins:

1656099774716.png



For twice as much one can get even superior models:

- https://www.lake-people.de/en/categories/headphone-preamps/lake-people-g105-mkii (balanced + unbalanced & balance control)
- https://www.lake-people.de/en/categories/headphone-preamps/lake-people-phone-amp-g111 (this one still the MKI model, a classic)

Anyway sorry about the off topic but I'm really excited to finally get a decent headphone amp haha, don't get me wrong I love everything in the M4 except the headphone amp (although it's better than the competition at this price point, like I had the Scarlett Gen 2 or 3 and they clearly sucked lol, I also had the Audient ID14 Gen 1 and actually that's the only feature I'd say that would be superior and more powerful vs. the Motu, but the Motu wins overall).

Just received my new cans of 990 Pro 250 ohm today, damn they sound even better than my dying 880 Pro. Looking forward to receive the amp & cable ordered.
 
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spnc

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Funnily someone replied to me at the same time on Gearspace, now I understand... I should have thought about the USB power thingie earlier :p

Screenshot 2022-06-24 at 21.58.16.png
 
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Trell

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Funnily someone replied to me at the same time on Gearspace, now I understand... I should have though about the USB power thingie earlier :p

View attachment 214461

What is missing is the impedance to go along with the power output (including distortion). There are a number of USB powered audio interfaces that have much more output at 300 Ohm, say, than 18 mW.

Here is one reviewed at ASR that is USB 2.0 powered: 37 mW at 300 Ohm, or 3 dB louder than 18 mW.

This device has on-board EQ/DSP with priority that you can always record when needed, so headphone output is by design limited. Recording is the most important task.

@Julian Krause has his own YT channel with many reviews of audio interfaces that includes headphone out measurements.

 
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spnc

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What is missing is the impedance to go along with the power output (including distortion). There are a number of USB powered audio interfaces that have much more output at 300 Ohm, say, than 18 mW.

Here is one reviewed at ASR that is USB 2.0 powered: 37 mW at 300 Ohm, or 3 dB louder than 18 mW.

This device has on-board EQ with priority that you can always record when needed.

@Julian Krause has his own YT channel with many reviews of audio interfaces that includes headphone out measurements.


Oh yeah absolutely, I follow @Julian Krause channel on YouTube - Germans again they're solid :) so useful.

Duly noted for the RME BabyFace Pro FS, yeah actually I've been looking at it lately, thinking oh look it seems more powerful even though it's USB powered. Interesting point, thanks!

By the way when I'm to upgrade from the Motu in the future I will want this one brand (not a fan of UAD) - most likely one of the latest released FireFace series.

When I saved up enough I'm thinking of pairing a FF with a ADI-2 DAC FS amp, do you think the FF is powerful on its own to drive 250 ohm or higher impedance headphones, or would the pair of FF + ADI amp be even safer in terms of having plenty enough headroom (this is an important feature for me, I mix 80% of the time with headphones due to living in a building with difficult neighbours especially at night haha)?

Thank you.
 

Trell

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Oh yeah absolutely, I follow @Julian Krause channel on YouTube - Germans again they're solid :) so useful.

Duly noted for the RME BabyFace Pro FS, yeah actually I've been looking at it lately, thinking oh look it seems more powerful even though it's USB powered. Interesting point, thanks!

By the way when I'm to upgrade from the Motu in the future I will want this one brand (not a fan of UAD) - most likely one of the latest released FireFace series.

When I saved up enough I'm thinking of pairing a FF with a ADI-2 DAC FS amp, do you think the FF is powerful on its own to drive 250 ohm or higher impedance headphones, or would the pair of FF + ADI amp be even safer in terms of having plenty enough headroom (this is an important feature for me, I mix 80% of the time with headphones due to living in a building with difficult neighbours especially at night haha)?

Thank you.

TL;DR Get the UCX II first and then the ADI-2 if you want the ADI-2 DSP features or more powerful headphone amp or just the remote.

I don't have the RME Babyface Pro FS, but I do own the MOTU M2, RME Fireface UCX II as well as the RME ADI-2 DAC FS.

I don't use the MOTU M2 any more is I've replaced it with the UCX II for mic duties. That said, the MOTU M2 can drive my Beyerdynamics DT-880 Edition 250 Ohm to satisfactory volume level for much content but not for all (especially for more quiet recordings), for the Beyerdynamics DT-1770 Pro 250 Ohm (much more sensitive) it's generally quite fine. The UCX II has a powerful headphone output that someone in the UCX II thread estimated to be 157 mW at 300 Ohm, and yes, it's powerful as I've noted myself in my own testing. The ADI-2 DAC is even more powerful, of course, and a little louder (doubling of power gives 3 dB more volume).

The UCX II is not USB powered, though, and is an excellent audio interface with very useful DSP but about 40-50% more expensive than the Babyface Pro. For an all-in-one device it would work very well for most headphones but the ADI-2 has DSP features that I want like dynamic loudness. Currently my UCX II is stacked upon my ADI-2 and connected to it using ADAT, so I use the headphone amp in the ADI-2 and not the UCX II.

So, as you write that you mix so much as you do I would get the UCX II not only for the much more powerful headphone out than the BabyFace but also the much improved DSP along with many more available channels (useful for loopbacks and routing, if you don't use all the physical connectors). The UCX II has DUREC so it can record to a memory stick as a backup or standalone. The TotalMix FX software is very powerful and useful.

Edit: A few links.

The UCX II home page that also has link to the comprehensive manual:


The UCX II announcement thread:


UCX II review with measurements by @Rja4000:


Review with specs and measurement (by @solderdude) for Beyerdynamics DT-880 Edition and DT-1770 Pro, for reference:

 
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