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MOTU 1248, 8M, 16A Thunderbolt interface Audio Interfaces
Old 29th July 2018
  #3571
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emrr's Avatar
Quote:
Originally Posted by ArborKnox View Post
Long time lurker, first time poster here, thanks in advance for any help - this is a shot in the dark, but here goes:

So at our studio, we have an ancient mid-70s MCI 500 series console, and we just upgraded converters to a MOTU 16A, wired to a MacBook Pro via Thunderbolt, running Cubase 9. We're just using the MOTU as a straight-up A/D interface, analog ins and outs corresponding to the first 16 channels on the board and using the MCI's preamps, and mixing in the box with Cubase. Everything runs smoothly, latency is pretty low (4ms), routing seems to work just fine, no pops or clicks or hardware glitches. So there's just one problem: the recorded audio doesn't sound quite right. It sounds okay, but there's a seeming lack of transient response and everything sounds just a tad.. fuzzy (and the MCI board has been well maintained and recapped and all that.) We're using the MOTU's clock, no external clock (never felt like we needed one in the past) - could this be a issue? The bit rates match up fine: we're recording 24 bit, 48k, reflected both in the MOTU web app and Cubase's main window. Or could it be something else entirely?

Thanks!
#1 thing to know, are the MCI inputs balanced or unbalanced? If unbalanced, the 16A is probably driving one side directly to ground, and this will make distortion go up. The 16A manual addresses it.

This is an aspect of the analog circuit design in these units that really doesn't stack up as 'professional', especially when there are plenty of circuit choices that would automatically compensate for balanced versus unbalanced connections.
Old 29th July 2018
  #3572
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Lady Gaia's Avatar
Quote:
Originally Posted by emrr View Post
#1 thing to know, are the MCI inputs balanced or unbalanced? If unbalanced, the 16A is probably driving one side directly to ground, and this will make distortion go up. The 16A manual addresses it.
Great observation. Nothing leapt to mind when the original inquiry was posted, but this would definitely be a reasonable explanation. I discussed my own discovery process and eventual custom cable order to address the issue of older outboard gear in this thread.
Old 29th July 2018
  #3573
Quote:
Originally Posted by ArborKnox View Post
...there's just one problem: the recorded audio doesn't sound quite right. It sounds okay, but there's a seeming lack of transient response and everything sounds just a tad.. fuzzy (and the MCI board has been well maintained and recapped and all that.) We're using the MOTU's clock, no external clock (never felt like we needed one in the past) - could this be a issue? The bit rates match up fine: we're recording 24 bit, 48k, reflected both in the MOTU web app and Cubase's main window. Or could it be something else entirely?

Thanks!
Have you tried bypassing the board (input connected directly into 16a)?
Or, Record same sound (say a keyboard with Line Out level) by multing keyboard output
1. To board>16a and
2. To 16a direct,
then compare recorded waveforms (invert phase of one and combine for difference file).

I'd perform as much testing as you can using various i/o approaches, then call MOTU and discuss.
Old 30th July 2018
  #3574
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emrr's Avatar
Quote:
Originally Posted by ArborKnox View Post
We're just using the MOTU as a straight-up A/D interface, analog ins and outs corresponding to the first 16 channels on the board and using the MCI's preamps, and mixing in the box with Cubase. the recorded audio doesn't sound quite right. It sounds okay, but there's a seeming lack of transient response and everything sounds just a tad.. fuzzy (and the MCI board has been well maintained and recapped and all that.)
Ok, I'm gonna try reading with comprehension again.....problem I described isn't yours, as you aren't using the 16A outputs, correct?

If so, I gotta wonder what your point of reference is; a previous converter? What? can you A/B that?

I did notice how astonishingly low the noise floor is in the 16A as compare to the 24i/o it replaced, the measurements showed a large difference, roughly 12dB, and I found the noise floor and low level resolution (by the numbers very respectable and seemingly below any point you'd have to worry about) of the 24i/o was STILL masking a good bit of background source noise, with the 16A revealing more starkly the noise floor and distortions of any equipment feeding it. Stuff you wouldn't think you could hear. The older converter also had a lot of hum/harmonics spiking much higher than the 12dB baseline difference, with the 16A having very little. I'm not saying that's your problem, but consider it. That extra stuff does add up to some 'warm fuzzy' soft focus.
Old 31st July 2018
  #3575
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locojohn's Avatar
Quote:
Originally Posted by flyingfadr View Post
after listening side by side against the 1248, the 1248 definitely sounds slightly better ( there's a reason for the extra $500 )... more depth, detail, and fuller in the mids.... some might not hear it, but it's there...
Honestly, I think there is no difference. The 828es is newer, only has 2 preamps and lacks a few other features of the flagship model (perhaps, this is the reason for price difference), but even according to MOTU they seem to share exactly the same D/A “and the same proven, award-winning audio quality as MOTU's flagship 1248”.

Andrejs
Old 31st July 2018
  #3576
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ponzi's Avatar
I presume they have the technologies for the various components and the different models are more or less the building blocks in different combinations--line pres, mic pres, headphone outputs and so on--economies of scale on chip purchases and the like. My 1428 gets a little warm, so I presume a linear power supply. I would guess more new products will be switching to switching power supplies--maybe one minor difference. I feel like their pace of new products has slowed down since the avb stuff came out, but maybe I just started looking at them during a new product portion of their life cycle.
Old 31st July 2018
  #3577
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Monkey Man's Avatar
 

My understanding is that it's the convertors in the 1248, 16A, 24Ai and 24Ao units that're responsible for the heat (most of it at least).
Old 31st July 2018
  #3578
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ponzi's Avatar
Quote:
Originally Posted by Monkey Man View Post
My understanding is that it's the convertors in the 1248, 16A, 24Ai and 24Ao units that're responsible for the heat (most of it at least).
Maybe, but I think its the transformer on the right hand side. (facing the front of the unit) Those converters are smaller than postage stamps and they don't have heat sinks.

Last edited by ponzi; 31st July 2018 at 08:45 PM..
Old 1st August 2018
  #3579
Here for the gear
 

Quote:
Originally Posted by emrr View Post
Quote:
Originally Posted by ArborKnox View Post
We're just using the MOTU as a straight-up A/D interface, analog ins and outs corresponding to the first 16 channels on the board and using the MCI's preamps, and mixing in the box with Cubase. the recorded audio doesn't sound quite right. It sounds okay, but there's a seeming lack of transient response and everything sounds just a tad.. fuzzy (and the MCI board has been well maintained and recapped and all that.)
Ok, I'm gonna try reading with comprehension again.....problem I described isn't yours, as you aren't using the 16A outputs, correct?

If so, I gotta wonder what your point of reference is; a previous converter? What? can you A/B that?

I did notice how astonishingly low the noise floor is in the 16A as compare to the 24i/o it replaced, the measurements showed a large difference, roughly 12dB, and I found the noise floor and low level resolution (by the numbers very respectable and seemingly below any point you'd have to worry about) of the 24i/o was STILL masking a good bit of background source noise, with the 16A revealing more starkly the noise floor and distortions of any equipment feeding it. Stuff you wouldn't think you could hear. The older converter also had a lot of hum/harmonics spiking much higher than the 12dB baseline difference, with the 16A having very little. I'm not saying that's your problem, but consider it. That extra stuff does add up to some 'warm fuzzy' soft focus.
First off, thanks to you, Lady Gaia, and everyone else for their thoughtful responses and input.

We have the 16 analog ins and outs wired 1-to-1 with the first 16 channels (in and out) on the MCI board. Although everything is physically connected, we're only using the MOTU analog inputs for now (the thought being that we could mix through the console instead of in the box if we so desired by sending stereo groups - we record mostly rock bands - back through the MCI channels, then print to the stereo out in Cubase.) Previously, we used a couple of old Metric Halo 8 channel interfaces for conversion. One of them bit the dust, so we decided to upgrade to the MOTU, having read numerous good reviews about it.

The reason I thought it might initially be a clocking issue is because everything I've read about "clock jitter" causing audio problems - undefined transients, kinda flabby low end with a lack of definition - is exactly what we're currently experiencing. It's not so much about noise and hum as it is just the overall quality of recorded audio - sorta hazy, fuzzy, real midrange-y. It doesn't sound "bad" per se but it "should" sound at LEAST as good at the Metric Halos, right? (and I know all of this is subjective.) Is it possible that there's some sort of grounding error on the cabling going from the MCI outputs to the MOTU ins? (please forgive my ignorance on this - the tech/under the hood stuff is definitely not my forte.)
Old 1st August 2018
  #3580
Quote:
Originally Posted by ArborKnox View Post
First off, thanks to you, Lady Gaia, and everyone else for their thoughtful responses and input.

We have the 16 analog ins and outs wired 1-to-1 with the first 16 channels (in and out) on the MCI board. Although everything is physically connected, we're only using the MOTU analog inputs for now (the thought being that we could mix through the console instead of in the box if we so desired by sending stereo groups - we record mostly rock bands - back through the MCI channels, then print to the stereo out in Cubase.) Previously, we used a couple of old Metric Halo 8 channel interfaces for conversion. One of them bit the dust, so we decided to upgrade to the MOTU, having read numerous good reviews about it.

The reason I thought it might initially be a clocking issue is because everything I've read about "clock jitter" causing audio problems - undefined transients, kinda flabby low end with a lack of definition - is exactly what we're currently experiencing. It's not so much about noise and hum as it is just the overall quality of recorded audio - sorta hazy, fuzzy, real midrange-y. It doesn't sound "bad" per se but it "should" sound at LEAST as good at the Metric Halos, right? (and I know all of this is subjective.) Is it possible that there's some sort of grounding error on the cabling going from the MCI outputs to the MOTU ins? (please forgive my ignorance on this - the tech/under the hood stuff is definitely not my forte.)
If you were to connect a pair of outputs of the 16A to a pair of its inputs and pass a stereo mix out and back in, that would help you diagnose the issue.

All my stuff gets multiple a to d and d to a conversions due to the way I work and the result is clear and great sounding check out the music in my signature all done on the 16A.

Cheers

Wiz
Old 1st August 2018
  #3581
Quote:
This is an aspect of the analog circuit design in these units that really doesn't stack up as 'professional', especially when there are plenty of circuit choices that would automatically compensate for balanced versus unbalanced connections.
Quote:
Ok, I'm gonna try reading with comprehension again.....problem I described isn't yours, as you aren't using the 16A outputs, correct?
Just to clarify, the MOTU inputs will accept unbalanced connections using standard 1/4" TS interconnect.

To connect the interface's outputs to an unbalanced input, one must use cables that, at the end attached to the MOTU, have a TRS plug with the ring left unconnected (floated). Per MOTU:
Quote:
Quarter-inch analog outputs are not cross-coupled. Therefore, use a TRS plug with the ring disconnected. Not floating the negative terminal will short it to the sleeve ground and cause distortion.
Old 2nd August 2018
  #3582
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loopy's Avatar
 

Windows 1803 and MOTU Ultralite AVB. Anyone having problems with the 1803 update to Windows 10 Professional? My box updated the other day and ever since I have been getting intermittant, weird distortion from the MOTU. It sounds like too low a buffer setting but using higher buffer/safety buffer settings doesn't help. Nothing else in my system has changed. Unplugging and re-plugging the USB cable or POR the unit fixes the problem until it happens the next time. This is just playing Youtube, streaming Amazon Prime music or playing local files. I haven't been recording lately so I don't know if ASIO is also effected.
I am at the latest firmware and driver levels for the MOTU.

I reverted back to the 1709 version and all has been well for a day so something is sick with the 1803, my system and MOTU.

Anyone else?
Old 2nd August 2018
  #3583
Gear Maniac
 

yeah! I have been experiencing this issues, I thought it was sonarworks software but could be windows....I sometimes fix it changing from 48k to 44k and back, but sometimes I have to reset the machine
Old 2nd August 2018
  #3584
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loopy's Avatar
 

Quote:
Originally Posted by pablo1980 View Post
yeah! I have been experiencing this issues, I thought it was sonarworks software but could be windows....I sometimes fix it changing from 48k to 44k and back, but sometimes I have to reset the machine
I thought it was Sonarworks too but I disabled it and set my default audio device to MOTU and I still had the same problems. Changing the sample rate sometimes fixed it for me as well. So far going back to 1709 seems to have fixed it for me. On the MOTU side, it failed with the latest firmware and also the previous version. At least on my system, the 1803 update seems to be the source of the troubles.

Maybe Travis from MOTU can respond?
Old 2nd August 2018
  #3585
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gradivus's Avatar
 

Quote:
Originally Posted by HCMarkus View Post
To connect the interface's outputs to an unbalanced input, one must use cables that, at the end attached to the MOTU, have a TRS plug with the ring left unconnected (floated). Per MOTU:
Is it TRS on both ends (with the ring left unconnected on MOTU output) or... TS on the side for your unbalanced device input and TRS with ring unconnected on MOTU output side?
Old 2nd August 2018
  #3586
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Lady Gaia's Avatar
Quote:
Originally Posted by gradivus View Post
Is it TRS on both ends (with the ring left unconnected on MOTU output) or... TS on the side for your unbalanced device input and TRS with ring unconnected on MOTU output side?
Both approaches would work, so you could use the former if you're just performing surgery on an existing cable. I lean toward the latter (TRS -> TS with the ring left floating) because it's easier to visually identify the cable as unusual.

This post includes the instructions I provided and a direct link to order the exact same cables I use for this purpose.
Old 2nd August 2018
  #3587
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Monkey Man's Avatar
 

Hey LG, I just realised something about the Kemper hookup and SRC.

The Kemper can only run on its internal clock, so doesn't this mean that whilst the 1248 would accept its output whilst running on its own clock thanks to SRC, the Kemper wouldn't be able to receive its S/PDIF out unless it somehow senses the Kemper's timing through the S/PDIF input and synchronises its output accordingly?

If this is the case, I'd need to set the 1248 clock to slave to the Kemper so that the latter receives a properly-timed stream at its input, wouldn't I?

If this is my only option, I'll need to confirm that I won't have to keep changing the clock source on the 1248. IOW, if I set it to, say, S/PDIF, would it automatically revert to "internal" in the absence of the Kemper's signal and also re-sync to it when I turn the Kemper back on?

Obviously I want to be able to avoid having to manually define the new source every time I fire the Kemper up and wait for DP's reloading of its audio system, buffers and plugins (including samples employed in a project).

Thank you in advance for any input(!) you might have on this, as well as to anyone else who can share some info.
Old 2nd August 2018
  #3588
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Lady Gaia's Avatar
If the Kemper insists on being the clock master then you’re quite right: you’ll need to slave your interface to it or suffer whatever behavior it might exhibit when there’s clock drift. The 1248 and 828es seem to handle this pretty gracefully, but the Kemper and other gear can be an entirely different story. Best to assume you need to get your clocks sync’ed as you suggested.

I can’t speak to the 1248, but if you tell the 828es to sync to an external source that isn’t present then you get no audio at all while it tries to lock down the clock. There doesn’t appear to be any way to get it to default to internal clocking in the absence of an clock signal (unless it happens after a longer delay than I’ve been willing to wait for.) You’re going to have to change the configuration. I’m surprised to hear about the dramatic reconfiguration DP exhibits when changing the clock source. I guess I could understand it for sample rate changes, but otherwise ... ? Perhaps someone more familiar with your specific configuration can weigh in.
Old 2nd August 2018
  #3589
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Monkey Man's Avatar
 

Thank you so much, LG.

I've seen no issues with the Kemper's clock stability on the K forum; it appears to work very-well.

Someone there told me a while back that most interfaces will revert to a default source automatically in the absence of an external one and re-sync when it appears again, but I didn't want to assume this would be the case with the 1248.

DP definitely does the audio-system-re-loading thing when one alters any settings in the audio-setup window, but I haven't tried this specific one as I've never had an alternative source (still on a PCI-424 system with "analogue" I/O only).

This "automatic" reversion and re-syncing is critical to me. If I can't find a quick way to switch manually in its absence, I won't be able to use the Kemper's S/PDIF I/O for recording and reamping, making it tougher to justify the 1248 in place of a 16A as my main device. I've been hoping that the quality of the preamps (ultra-flat on paper at least) would mean that I could use one of them for my Slate VMS mic instead of the "wedge" preamp, which presents physical-placement issues. This, along with the RCA S/PDF connections for the Kemper, would make the unit ideal for my proposed setup. Learned the hard way too-many times that it's best to seek absolute performance guarantees before committing.

Thank you again, LG. Travis, wherefore art thou?
Old 2nd August 2018
  #3590
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Lady Gaia's Avatar
Quote:
Originally Posted by Monkey Man View Post
DP definitely does the audio-system-re-loading thing when one alters any settings in the audio-setup window, but I haven't tried this specific one as I've never had an alternative source (still on a PCI-424 system with "analogue" I/O only).
One quick observation while you’re waiting for others: this shouldn’t require changing anything in DP’s audio setup. Can’t you just go to the web console for the 1248 and change the clock source behind your DAW’s back? So long as you’re not changing sample rate it shouldn’t really care...
Old 2nd August 2018
  #3591
Quote:
Originally Posted by gradivus View Post
Is it TRS on both ends (with the ring left unconnected on MOTU output) or... TS on the side for your unbalanced device input and TRS with ring unconnected on MOTU output side?
TS connected at unbalanced end.

TRS at MOTU output end with ring floated.

You can simply use TRS cables (TRS at both ends) to accomplish the same thing. At the unbalanced jack, no contact will be made with the ring, essentially floating the ring conductor at both ends. Whether that opens up potential for RF interference is another question.

Think about how a TS 1/4" jack contacts a TS or TRS plug (no difference) then how a TRS jack contacts a TS or TRS plug.. big difference! When TS plug is inserted in a TRS jack, the sleeve shorts the ring and sleeve contacts. By using a TRS plug with floated ring, this is avoided.

Sound System Interconnection
Old 2nd August 2018
  #3592
Quote:
Originally Posted by HCMarkus View Post
TS connected at unbalanced end.

TRS at MOTU output end with ring floated.

You can simply use TRS cables (TRS at both ends) to accomplish the same thing. At the unbalanced jack, no contact will be made with the ring, essentially floating the ring conductor at both ends. Whether that opens up potential for RF interference is another question.

Think about how a TS 1/4" jack contacts a TS or TRS plug (no difference) then how a TRS jack contacts a TS or TRS plug.. big difference! When TS plug is inserted in a TRS jack, the sleeve shorts the ring and sleeve contacts. By using a TRS plug with floated ring, this is avoided.

Sound System Interconnection
This is how I have run my setup 16A into TRS patchbay into Soundcraft Delta for a few years now.

Cheers

Wiz
Old 3rd August 2018
  #3593
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Monkey Man's Avatar
 

Quote:
Originally Posted by Lady Gaia View Post
One quick observation while you’re waiting for others: this shouldn’t require changing anything in DP’s audio setup. Can’t you just go to the web console for the 1248 and change the clock source behind your DAW’s back? So long as you’re not changing sample rate it shouldn’t really care...
Genius!

I've never had to change clock sources before; that's my excuse. Makes sense to me, LG. Thank you so much, man!

OK, so assuming this doesn't take long, I'd fire the Kemper up, switch the source, track a DI / processed signal from it via S/PDIF and /or reamp a DI track through it, switch sources again and then turn the KPA off, the final events in that sequence being to minimise the possibility of the MOTU's becoming stuck in a clock-source search and locking me out for a while?

Still a bit of a procedure. Not sure if it properly-trumps the analogue route (the KPA has great convertors), but combined with the preamp usage for Slate's VMS, it might well justify the 1248 over the 16A.

Thank you once again, mate!
Old 3rd August 2018
  #3594
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Quote:
Originally Posted by HCMarkus View Post
Oh I know the horror of using one out of the box when it's not needed. When I was starting out they sold me TRS - TRS cable instead of TS - TS at a music store and I got instant hum.

Thanks for the explanation.
Old 3rd August 2018
  #3595
Gear Maniac
 

Just to echo some posts from above. The latest drivers seem pretty unstable to me on Win 10. I'm back to not being able to change sample rates with Pro Tools crashing, which they seemed to have fixed with the previous driver.
Old 3rd August 2018
  #3596
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loopy's Avatar
 

Quote:
Originally Posted by bulley View Post
Just to echo some posts from above. The latest drivers seem pretty unstable to me on Win 10. I'm back to not being able to change sample rates with Pro Tools crashing, which they seemed to have fixed with the previous driver.
Are you on the 1803 build of Windows? All my problems started after that upgrade and at the time I was on the previous MOTU drivers. I updated to the latest MOTU drivers and still had the same problems. Reverting Windows back to the previous 1709 build seems to have solved my problems. It's been 2 solid days without any failures. Not using Protools though. My problems happen even with YouTube, Amazon Streaming, local music playing.
Old 3rd August 2018
  #3597
Gear Maniac
 

Quote:
Originally Posted by loopy View Post
Are you on the 1803 build of Windows? All my problems started after that upgrade and at the time I was on the previous MOTU drivers. I updated to the latest MOTU drivers and still had the same problems. Reverting Windows back to the previous 1709 build seems to have solved my problems. It's been 2 solid days without any failures. Not using Protools though. My problems happen even with YouTube, Amazon Streaming, local music playing.
Still on 1709. Things happened when I updated MOTU drivers, I've dropped back but still having same problems so I'm slightly concerned it might be the updated firmware causing the trouble.

Edit: Can confirm new firmware is a nightmare for me PT12 Win10, I can't change sample rates, just hangs. I have to create sessions using a different soundcard then switch to the MOTU to get them to work. Bobbins.

Last edited by bulley; 3rd August 2018 at 02:15 PM..
Old 4th August 2018
  #3598
Here for the gear
 

I just updated the most recent firmware (1 Aug) to my 828es. Now none of my routings work any more. The new firmware has caused changes, but I do not know what. Anyone else had this problem?
Old 4th August 2018
  #3599
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Lady Gaia's Avatar
Quote:
Originally Posted by smoltron View Post
I just updated the most recent firmware (1 Aug) to my 828es. Now none of my routings work any more. The new firmware has caused changes, but I do not know what. Anyone else had this problem?
Sorry to hear about the inconvenience. Have you tried downgrading to the prior firmware?

I updated this morning after seeing your message and everything seems to be working normally for me. Anything in particular I should look out for, or do even basic routings to the mixer and monitor outs fail for you?
Old 5th August 2018
  #3600
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ponzi's Avatar
Guts of a 1248 for those interested in such things:

1248 — imgbb.com
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