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Solid upgrade from Motu M2?

reter

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Jan 19, 2021
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I'm looking for an upgrade from the motu m2 audio interface

just to be clear, i want to upgrade the adc , NOT the dac since i'll be using the device to record from mics


any suggestions?
 
I think any real upgrade will cost significant money. How much is the budget?
 
Is this the latest version M2 with the ESS ADC or the older one with an AKM?
What kind of microphones are we talking about (and what kind of peak SPL levels)? Which sample rates are to be used?
Will two mic inputs be sufficient or do you need more?

TBH the M2 is no slouch. The AKM ADC digital filters are a bit meh (below 192k in particular), but its input dynamic range is above average and peak input level handling is more than decent, mic input EIN is fine, and it's among the least expensive interfaces to use a PGA-based input amplifier chip so should not completely tank in distortion and bandwidth at high gain, even if distortion at full input for the old version is a bit meh. Plus the low latency A/D + D/A, and a rather decent headphone output (no the most powerful but clean).

For a substantial upgrade all around you can probably expect to spend about 3 times as much... think Focusrite Clarett+ 2Pre or RME Babyface Pro FS. (If you just want something similar with a fancier ADC chip, the new Scarlett 4th gen 2i2/4i4 would be worth a look.) If you need to handle pretty much the entire dynamic range of a large-diaphragm condenser without having to set the gain and thought the "old" M2 ADC was more than fine, the Zoom UAC-232 will be worth a look. (Note that it can handle about 6 dB less maximum input, but if you never were anywhere near 0 dBFS at minimum gain on the M2 that should not be a problem.) Or you could go all out with a Neumann MT48, which uses a higher-grade implementation of a similar concept composite ADC.
 
Is this the latest version M2 with the ESS ADC or the older one with an AKM?
What kind of microphones are we talking about (and what kind of peak SPL levels)? Which sample rates are to be used?
Will two mic inputs be sufficient or do you need more?

TBH the M2 is no slouch. The AKM ADC digital filters are a bit meh (below 192k in particular), but its input dynamic range is above average and peak input level handling is more than decent, mic input EIN is fine, and it's among the least expensive interfaces to use a PGA-based input amplifier chip so should not completely tank in distortion and bandwidth at high gain, even if distortion at full input for the old version is a bit meh. Plus the low latency A/D + D/A, and a rather decent headphone output (no the most powerful but clean).

For a substantial upgrade all around you can probably expect to spend about 3 times as much... think Focusrite Clarett+ 2Pre or RME Babyface Pro FS. (If you just want something similar with a fancier ADC chip, the new Scarlett 4th gen 2i2/4i4 would be worth a look.) If you need to handle pretty much the entire dynamic range of a large-diaphragm condenser without having to set the gain and thought the "old" M2 ADC was more than fine, the Zoom UAC-232 will be worth a look. (Note that it can handle about 6 dB less maximum input, but if you never were anywhere near 0 dBFS at minimum gain on the M2 that should not be a problem.) Or you could go all out with a Neumann MT48, which uses a higher-grade implementation of a similar concept composite ADC.

How do i know which chip has my motu M2? there's a serial number which says 2019-2021 next to it, so i don't really know when is made
 
How do i know which chip has my motu M2? there's a serial number which says 2019-2021 next to it, so i don't really know when is made
If opening it is out of the question, you could try running a loopback test using either RMAA or REW to determine the frequency response at 44.1/48k. REW can be trickier to get working right but may be you only sensible option if you're on a Mac or something.

If everything works well it shouldn't be too hard to spot the +/-0.03 dB periodic passband ripple of the AKM's digital filter if you zoom in a bit. (If you see something much bigger / different in REW, something about the windowing is messed up.)
ak55xx-singlespeed-periodripple.png

In any case you still haven't answered all of the other questions. (BTW, I was asking about microphone types more so than specific models. There's no point in looking for something with super-low EIN if you're going to be using a condenser. But then input level handling may become a concern if you expect levels in excess of 130 dB SPL, which might occur with someone screaming directly into the mic or something.)
 
If opening it is out of the question, you could try running a loopback test using either RMAA or REW to determine the frequency response at 44.1/48k. REW can be trickier to get working right but may be you only sensible option if you're on a Mac or something.

If everything works well it shouldn't be too hard to spot the +/-0.03 dB periodic passband ripple of the AKM's digital filter if you zoom in a bit. (If you see something much bigger / different in REW, something about the windowing is messed up.)
View attachment 314094
In any case you still haven't answered all of the other questions. (BTW, I was asking about microphone types more so than specific models. There's no point in looking for something with super-low EIN if you're going to be using a condenser. But then input level handling may become a concern if you expect levels in excess of 130 dB SPL, which might occur with someone screaming directly into the mic or something.)

yeah, i don't need much input level, my mics are condensers, motu is pretty ok but i've already heard about this roll-off and i'm a bit concerned because the 48khz is something i use for some of my recordings

also, as i understand adc chips have different manufacturers and aren't all realiable to all samples, then can you suggest something very reliable at 48khz, maybe for the same price or a little more than the m2?
 
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then can you suggest something very reliable at 48khz, maybe for the same price or a little more than the m2?
Here are some potential candidates, ordered by descending price (going by Thomann, specifics may vary depending on where you are) and assuming your M2 is an "old" one, with ADCs used:

Focusrite Clarett+ 2Pre - CS5381
Audient iD24 - ES9822PRO
MOTU M4 (current production) - ES9840
Focusrite Scarlett 4i4 4th gen - CS5381
MOTU M2 (current production) - ES9820
Audient iD14 MkII (current production) - ES9822PRO
Focusrite Scarlett 2i2 4th gen - CS5381

There'll be no doubts about filter performance with the CS5381, which has exactly one option per sample rate, well-documented in the datasheet. (It's fairly close to bulletproof at 48k.) With the ESS ones there'll be some choice in the matter, though I wouldn't call any of the options bad, quite the contrary - you're generally better off than with the AK55xx filter for one reason or another with any of them, I just wish there was another intermediate setting for a better compromise between passband ripple and stopband rejection (basically, one of them is always just "decent" while the other one is spectacular). The linear phase fast rolloff filter even rivals the old AK5394A for being bulletproof at 44.1 kHz, not to mention filter performance doesn't get worse at all up to 192 kHz.
 
Here are some potential candidates, ordered by descending price (going by Thomann, specifics may vary depending on where you are) and assuming your M2 is an "old" one, with ADCs used:

Focusrite Clarett+ 2Pre - CS5381
Audient iD24 - ES9822PRO
MOTU M4 (current production) - ES9840
Focusrite Scarlett 4i4 4th gen - CS5381
MOTU M2 (current production) - ES9820
Audient iD14 MkII (current production) - ES9822PRO
Focusrite Scarlett 2i2 4th gen - CS5381

There'll be no doubts about filter performance with the CS5381, which has exactly one option per sample rate, well-documented in the datasheet. (It's fairly close to bulletproof at 48k.) With the ESS ones there'll be some choice in the matter, though I wouldn't call any of the options bad, quite the contrary - you're generally better off than with the AK55xx filter for one reason or another with any of them, I just wish there was another intermediate setting for a better compromise between passband ripple and stopband rejection (basically, one of them is always just "decent" while the other one is spectacular). The linear phase fast rolloff filter even rivals the old AK5394A for being bulletproof at 44.1 kHz, not to mention filter performance doesn't get worse at all up to 192 kHz.
thank you, i will try the focusrite 4i4 4th gen with his CSS chip and xlr inputs, that's what i need the most

Is there a difference in timbre or spacial presentation between adc chips? i'm asking because i had the behringer uphoria before the motu m2 and the way it sounds is slightly different between the two, what kind of adc chip does the behringer have?
 
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Which Behringer specifically? U-Phoria is just a generic brand name for their USB audio interfaces. UMC22 (PCM2902)? UMC202HD (CS4272), UMC204HD (CS4272 + CS4271), UMC404HD (CS4272 x2)? I would rather suspect the Behringers' preamps in this case, which have a reputation for high levels of dominant-H2 distortion at higher gains and premature clipping.
 
Which Behringer specifically? U-Phoria is just a generic brand name for their USB audio interfaces. UMC22 (PCM2902)? UMC202HD (CS4272), UMC204HD (CS4272 + CS4271), UMC404HD (CS4272 x2)? I would rather suspect the Behringers' preamps in this case, which have a reputation for high levels of dominant-H2 distortion at higher gains and premature clipping.
umc202hd, so they have the same manufacturer but a better one
 
The CS4272 ADC is much the same as a CS5361, yes (the standalone part may have a hair less distortion still but that's about it). The Behringer's analog stages running on +5V single-supply with inexpensive opamps are definitely the bottleneck though... it's a typical sub-$100 interface in that respect (no budget for an inverter to generate -5V at least). Tons of audio interfaces are using CS4272s (Focusrite Scarlett 1st-3rd gen, Arturia Minifuse, Tascam UA-2x2HR, UAA Volt and many more), CS5361 and its multichannel relatives (64, 66, 68) are not exactly too rare either - you should find plenty of instances listed. These are midrange workhorse parts and have been for years.
 
In my experience i cannot get enough power to my Podmic even with maximum gain on my Motu M2. I have to use a cloudkicker.

Would a Moth M6 provide the same power or more? Would a Clarett 2pre give enough juice without hacing to use a cloudlifter?

Im looking for an upgrade myself from the M2.

One thing that satisfies my needs with the Moth M6 is the inputs are on the back ❤️
 
In my experience i cannot get enough power to my Podmic even with maximum gain on my Motu M2. I have to use a cloudkicker.

Would a Moth M6 provide the same power or more? Would a Clarett 2pre give enough juice without hacing to use a cloudlifter?

Im looking for an upgrade myself from the M2.

One thing that satisfies my needs with the Moth M6 is the inputs are on the back ❤️
Probably the same gain, I don't see it called out on their specs. The chip-based pres are mostly going to be a little light on gain without the cloudlifter. In a nut shell, if an interface isn't boasting 60-70 dB gain on their mic pres, they probably don't have 60-70. I think an Apollo has about 65 dB gain, but I think the more budget priced interfaces in general don't have that much. Or, you could get a condenser mic.
 
Probably the same gain, I don't see it called out on their specs. The chip-based pres are mostly going to be a little light on gain without the cloudlifter. In a nut shell, if an interface isn't boasting 60-70 dB gain on their mic pres, they probably don't have 60-70. I think an Apollo has about 65 dB gain, but I think the more budget priced interfaces in general don't have that much. Or, you could get a condenser mic.
What would the successor to a chip-based pre look like?
 
According to Julian Krause the M2 has 52 db of mic gain while the MOTU Ultralight mk 5 has 75 db of gain. So that would be a solid upgrade from the M2.

Might look at the Lewitt Connect 6 as it has 72 db gain on mics.
 
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What would the successor to a chip-based pre look like?
Well, I'm not up on the current chips and specs, I'll just give you a general idea of what I mean.

It's not so hard to give 70 dB gain, but it's hard to give 70 dB of clean gain. 70 dB is a factor of 3162 times the input level. 50 dB is a factor of 316.

The noise floor of electronics depends on how clean your layout is, and components, but ultimately there is a minimum noise floor that you can't go below, due to things like thermal noise, which is constant (with resistance and temperature, but I mean there is a level that you can't get quieter than). Normally it's too quiet to hear, but in this case we're using a boat load of gain, which brings up the noise floor.

The only way to increase your signal to noise and therefore dynamic range is to expand your maximum output—you can't make the minimum output less than thermal noise, so you boost your max output. If you're using plain op-amps, they have a limit (something less than the supply rails). There are dedicates mic preamp chips that can do better, and also discrete op-amps that are less restricted. Tubes generally have high voltages, so that's another way. Also transformers can help. And of course combinations—IIRC one of Rupert Neve's designs used op-amps but extended their range with additional components (transistors? I think it was transformer-less, but maybe it wasn't).

The point here is that inexpensive boxes use inexpensive designs. Obviously, transformers, tubes, and discrete op-amps are already a no-go, due to cost, but even if some of the dedicated chips (THAT, etc.) have enough gain (they might, I just don't have time to look them up), their cost will perhaps be too high for a budget box.

Something like UA Apollo had high gain pres. As @Blumlein 88 notes, Julian Krause says that the MOTU Ultralight mk 5 does 75 dB, and I assume that's clean, as Krause is a pretty thorough guy. I see Motu says 74 dB, so Krause's claim seems in line. Amir has a review, looks impressive for the price:

MOTU UltraLite-mk5 Review (Audio Interface)

Note that the Ultralite is $250 more than the M6, more i/o, but half the number of mic pres (2 vs 4). So they can afford the higher-gain pres.

I use external mic pres, I use an interface with no mic pres (Motu M64 + Ferrofish Pulse 16 MX).
 
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