Problem when using an 828mk2 as ADAT expander (standalone) - only 4 channels work

[parkellipsen]

Hi,

sorry if this is not the right place to ask (just delete this if it isn't), but I'm trying to configure a Firewire 828mk2 as a standalone ADAT converter, using the on-board menus only (neither I nor any friend of mine has a computer with Firewire anymore).

I followed this guide: https://motu.com/techsupport/technotes/ ... 7968752604

The problem is, I'm only getting ADAT input on channel 5-8, but not channels 1-4.

There might be different reasons for the problem ... either my main interface has a problem (even though I have 2 of the same make and it's the same with both) or the 828 is broken (it looks fairly battered).

But before I give up on it, I thought I might ask whether there's some "magic setting" somewhere that I've missed.

Any ideas ?

Best,
N

[James Steele]

What sample rate are you using? Forgive me if I'm way off because I don't own any ADAT expanders, but I have read that if you're using a sample rate higher then 48k, like 88.2k or 96k, it reduces the number of channels??? Again, just taking a shot in the dark here.

[bayswater]

if you're using a sample rate higher then 48k, like 88.2k or 96k, it reduces the number of channels

That's correct.

[mikehalloran]

Hi,

sorry if this is not the right place to ask (just delete this if it isn't), but I'm trying to configure a Firewire 828mk2 as a standalone ADAT converter, using the on-board menus only (neither I nor any friend of mine has a computer with Firewire anymore).

I followed this guide: https://motu.com/techsupport/technotes/ ... 7968752604

The problem is, I'm only getting ADAT input on channel 5-8, but not channels 1-4.

There might be different reasons for the problem ... either my main interface has a problem (even though I have 2 of the same make and it's the same with both) or the 828 is broken (it looks fairly battered).

But before I give up on it, I thought I might ask whether there's some "magic setting" somewhere that I've missed.

Any ideas ?

Best,
N

if you're using a sample rate higher then 48k, like 88.2k or 96k, it reduces the number of channels

That's correct.

What they said.

If everything is set to 44.1 or 48kHz, let us know.

This should default to 44.1k as a standalone converter from the analog inputs. If it doesn't, try resetting to factory default settings:

828mkII: Disconnect Firewire. Press the Setup knob until the LCD screen reads "Clock Source". Turn the Setup knob all the way to the right. The LCD screen will read "Factory Defaults Press [SELECT]".

[parkellipsen]

Hey, thanks for all the replies

Yes, it's set to 44.1k ... I use the main interface as a clock source, and it's running at 44.1k ... if the optical cable is not connected, I can see the samplerate indicator blinking, and it stops blinking when I plug it in, and shows 44.1.

So I assume that's not the problem.

I also re-set everything to factory before I started.

[bayswater]

That was the only obvious thing I could think of. Can you test the optic cables?

[CharlzS]

Are you trying to connect 2 828s together in standalone mode or is the main interface something else? The issue could be on the receiving end.

[parkellipsen]

No, the main device is a different make and model, and I'm trying to get more outputs, so the MOTU is the receiver, the main device the sender.

Not ruling out that the problem is on the sender side, but as I said, I tried two different devices (of the same make and model) as a sender, and it's the same problem ... either they're both broken, or it's some general incompatibility ...

I should probably get another optical cable to test, true ...

[CharlzS]

I should probably get another optical cable to test, true ...

Not necessarily. It's been my experience that optical cables are either good or bad - there's not a partially working scenario.

What is the main interface? So ADAT out from the main interface to ADAT in on the mkII, the optical in on the mkII is set to ADAT, mkII is clocked to ADAT @ 44.1k (with main interface @ 44.1k), and you dialed in the mixbus setup correctly. Just a recap.

[parkellipsen]

I should probably get another optical cable to test, true ...

So ADAT out from the main interface to ADAT in on the mkII, the optical in on the mkII is set to ADAT, mkII is clocked to ADAT @ 44.1k (with main interface @ 44.1k), and you dialed in the mixbus setup correctly. Just a recap.

Mostly, except that the mkII uses the ADAT in as a clock source. EDIT: oops, sorry, that's what you wrote ... so, yes, your recap is correct.

Main interface (don't laugh) is a Behringer UMC1820.

[CharlzS]

Not familiar with that interface. I use a Behringer ADA8200 for an expander, so no laughing. The UCM is set to 44.1k also. It should be pretty straight forward. It looks as though either the UCM isn't sending ADAT 1-4 or you need to recheck the first 2 mixbus and level settings on the mkII.

[mikehalloran]

The very newest 828mkII was built in 2006. I bought mine in 2007 at a GC closeout after the mk3 was announced January NAMM. That’s over 17 years.

If nothing else works, time to take the cover off. Look for burnt resistors, cold solder joints, bulging caps, burnt traces around the optical connectors etc. If you don’t see anything obvious, burnish all connectors by unplugging and reconnecting each 3x before moving to the next. Reseat socketed ICs—once is enough. Reassemble. Is this a Hail Mary? Oh yes. Does it work? Far more often than you might think. The tiniest bit of corrosion in the wrong place can shut down a piece of gear completely. Can’t hurt.

[parkellipsen]

That might be worth a shot. But before that, I still have to try some other devices ... I was rummaging through the space I'm renting with friends and found an equally battered Traveler MkIII ... also Firewire, and thus unused. I'll give that one a shot.

There's even an old 828mkI that no one's using ... a shame that there's no way to attach firewire devices to recent computers ...

[HCMarkus]

a shame that there's no way to attach firewire devices to recent computers ...

IIRC, if you use a couple of the right adaptors, you CAN! I fully expect that Mike will chime in, but you may want to search the posts...

[parkellipsen]

Ok, so the Traveler MKIII is receiving ADAT on all channels, from the Behringer, so I assume the first four channels on the 828mkII are just broken somehow ...