828ES odd phase issues with Analog insert

[Domy Castellano]

Hello,

I recently bought a Motu 828ES. The unit has been great so far. I'm using it as my main Interface in my studio, with analog gear (SSL Fusion, Tegeler Creme etc.) connected to it. I used to have a Motu 828 mk3 which gave me no phase issues when using analog gear but now I'm struggling with the ES. I notice that when I insert analog gear in Ableton (like I always did) there are now some strange phase issues happening (though not very evident). This becomes very apparent when I collapse the signal to mono, after the analog insert. There's an obvious loss in "punch" and what's even funnier is that if I collapse the signal in mono BEFORE the analog insert, it becomes stereo again in a weird way (hope this makes sense). I never had any problem like this with the old Motu and I think it has to do with the routing of the 828ES. What are your thoughts?

Thanks for your patience.

[CharlzS]

Are you monitoring through two sources, hardware and DAW? In the Mixing Panel of Pro Audio Control, are your inputs for the outboard inserts muted? I'm just feeling my way around the ES coming from a mk2 - little bit of a steep learning curve compared to the older units.

[Domy Castellano]

Hello CharlzS,

Me and Travis Hagan from Motu are trying to figure out what is happening. I already checked for the mixer and unfortunately the inputs are already muted. It's not something that has to do only with the monitoring. We tried looping cables from various inputs and outputs and the resulting waveform has something really odd going on, Stereo-wise and Tone-wise (Sounds like comb-filtering and phase cancellation to me). Also the signal loses a lot of gain. I'm attaching some screenshots I did for Travis here :

Test Tone without Insert
https://ibb.co/cbcP38b

Test Tone with Insert
https://ibb.co/Xs42HN3

Both Test Tones
https://ibb.co/fd4rgLm

My routing
https://ibb.co/xH9DxPk

The funny part : Here I matched the two waveforms from the test tones, before and after the analog insert
https://ibb.co/R9pfQkg

I'm wondering if the issue is from the unit itself...

[CharlzS]

Something I ran into a couple of days ago - is your talkback mic live? Check the routing on your talkback. Out of the box I didn't think about the onboard talkback. It was picking up room and putting it back in. Something I must have messed up/overlooked in my initial routing/config.

[Domy Castellano]

I thought about that too so I removed every connection to it but the problem unfortunately is still there.

It really seems like there's a difference between the Left and Right analog channels...Again, the funny part is that if I send a mono signal into the analog channels, it becomes oddly stereo, while with the mk3 it would have added just a little bit of noise from the analog routing.

[CharlzS]

Are you trying to configure for an Audio Interface for a DAW? I have all my Mix In set to the physical inputs of the device for thru hardware monitoring and I see yours are all set to from the computer. Just for grins, take your AVB Streams and your To Mix channels down to zero (that will eliminate the mixer completely). That's just inputs to the computer and outputs from the computer (I guess like the original 828). Just something to try to isolate issue. Screen image: https://imgur.com/a/QC6xzJA

[Domy Castellano]

I tried that too but unfortunately it seems that the waveform is getting "skewed" by being processed through the I/O of the 828Es (as I showed in the screenshots)

Just for fun I reconnected my old mk3 and did the same thing, passing a test-tone and a stereo drum-loop through a Tegeler Creme and with no surprise everything was good. Stereo-image, phase etc. very solid and without issues. No wacky waveforms or mono-to-stereo effects from the processing. I'm still thinking this has to do with the hardware and not the software...

Here's a screen of the two test-tones

https://ibb.co/v32BfgV

[CharlzS]

I'm not familiar with Live - is there anywhere in Live where you set the loop back latency like what's necessary in PT or ping the device for latency? That would be different between the ES and MK3 and the only other thing I can think of.

[Domy Castellano]

You mean the Hardware Latency? Sure, I always compensate for that.

This device is for the External Instruments but it's the same for External Audio "Effects".

https://www.attackmagazine.com/wp-conte ... rument.png

What a mystery

[Domy Castellano]

Travis from Motu Support suggested using Input 1-3 instead of 1-2 and it seems that the problem doesn't appear in this case...that's quite interesting. I'm gonna try connecting my analog gear using this scheme later and see if this does the trick!

[studiocubico]

Hi!

I'm having the same issue with my 896mk3, and just on input channels 1-2.

Changing to 3-4 sounds just fine... Did you find the reason why? I'm trying not to loose the option of using that pair as a hardware insert.

Thanks in advance!!

[EMRR]

Don't know that this is in any way related, but I just had some in/out assign confusion arise from having changed things in the 16A AVB routing grid with DP open. Once changed the assignments all looked correct but the a loopback of a mix out through hardware back to an input pair was skewing heavily to one side. I changed the output bus to sum mono for troubleshooting and confirmed the input path was still skewing. blah blah blah.....the fix was changing the input assignment to something else and back, then it was coming in correctly. So....invisible routing confusion.