16 simultaneous I/O on 192

[greglawrence]

I seem to be missing something,

I'm trying to make use of all 16 I/O's on the 192. I've always just used it for 8 but am going to be recording a live show where I'll need all 16 directly into pro tools.

I'm hooked up to the analog inputs and the AES/EBU digital with a digilink cable for each, but am only getting any signal through the analog inputs. Digital is set to AES/EBU under hardware setup and the signals are all present in the mixer, just not getting into the 192's digital inputs.

The reference guide isn't really enlightening me so I'm hoping someone here can.

Thanks,

[Stig Eliassen]

The 192 I/O is capable of recording 8 digital and 8 analog tracks simultaneously. What are your sources?

I've on several occasions recorded 8 analog sources from my mic pres, and 8 digital sources from my Yamaha 01V (AES/EBU).

[greglawrence]

The signal going into the analog inputs is coming from a mackie (just to test for now). The signal going into the AES/EBU is coming from a digi 002 in standalone mode.

I think I realize where I was confused. I can get the digital input using an optical connection, but I was trying to avoid that since I've been having problems with clicks and pops, even though everything appears to be synced properly. They are sometimes very random clicks (like once every few minutes), but persistent.

Anyway, I was using a TRS to DB25 digilink cable and simply connecting it from the TRS main outputs of the 002 to the AES digital input of the 192 (for a stereo signal to test). That's my problem, isn't it. It's an analog signal - [**SMACK FOREHEAD***]. I guess I was totally thinking that when using the AES input that it was taking an analog signal and then converting it internally.

So what kind of digilink cable do I need to use the AES digital input? And, the 002 only offers optical for 8 channels of digital output. Do I have to use optical then? I was planning on using 8 direct outputs from the location mixer and then using my 002 in standalone mode for the 8 digital inputs.

Thanks for your help!

[audiogeek1]

You should not need the AES inputs. The optical inputs on the 192 would be what you would use. Make sure you have you PT system clocked to the optical imput and you are feeding optical both ways. This will help with your issues I think. Although I am not sure the OO2 will allow for the optical to be used in stand alone mode.

Mike

[greglawrence]

You should not need the AES inputs. The optical inputs on the 192 would be what you would use............Although I am not sure the OO2 will allow for the optical to be used in stand alone mode.

The optical I/O's on the 002 are available in stand alone mode. All eight inputs get passed directly to the ADAT optical outputs when preferences are set to do so, but the random clicks and pops still exist when I do this (even when pro tools is saying I've got sync). Is it possibly because the optical cables are too long? They're 25' cables.

So....., if I can't fix the pops and clicks using optical, then I do want to be able to use the AES inputs, even if I don't *need* to. Where I'm confused though, is what type of cables I need for digital AES connectivity?

[Barnabas]

The AES/EBU digital protocol uses a balanced cable, two insulated conductors plus a shield. It's like a balanced audio cable, but uses a special 110 ohm wire rather then what you'd use for an analog line-level signal. For short runs (a few feet), you could use a mic cable, but it’s always best to use the correct cable when you can.

AES/EBU cables are usually terminated with a 3-pin XLR connector or 25-pin connector, like on the back of the 192.

If you have a mixer or set of preamps with a 25-pin AES/EBU output, then you could get a 25-pin to 25-pin AES/EBU cable made up to connect the two.

If your mixer or preamps have an XLR-type AES/EBU connectors, then you could have a break-out cable made up with eight XLR connectors at one end and a 25-pin connector at the other end. Half of the XLRs would be male and half would be female. Each XLR would either send or receive two digital channels depending on where they connect to the 25-pin connector. At higher sampling rates, you have four inputs and outputs rather than eight. What I’ve just described is the “DB25-XLR M+F AES/EBU DigiSnake.” See page 34 in the 192 I/O Guide for the pin-out diagram. That diagram might help make sense of this.

There are black boxes that can convert one kind of digital signal to another. Thus you could use an external box to convert your ADAT optical to an AES/EBU signal to go to the 192. I don’t think that you’d gain anything by doing this.

[audiogeek1]

The optical I/O's on the 002 are available in stand alone mode. All eight inputs get passed directly to the ADAT optical outputs when preferences are set to do so, but the random clicks and pops still exist when I do this (even when pro tools is saying I've got sync). Is it possibly because the optical cables are too long? They're 25' cables.

So....., if I can't fix the pops and clicks using optical, then I do want to be able to use the AES inputs, even if I don't *need* to. Where I'm confused though, is what type of cables I need for digital AES connectivity?

Sounds like a bad cable not the length. Do any of them have a hard bend in it. This could be where you problem is. If they look good I do not know what else could be the problem. It should work.

Mike

[greglawrence]

Sorry I disappeared for a while. Figuring out this problem is second priority to the other projects I'm working on just now and I've been a bit busy. Thanks a lot for your thoughts guys, I've learned some things.

And, I've figured it out is seems.

First off, I just didn't realize that there was such a thing as a digital AES connection. So that's one thing I've learned. I couldn't use the digital AES inputs on the 192 since I don't have the appropriate outputs on the digi 002 (unless I ran out of the 8 mono analog outputs into a designated A/D converter that had appropriate AES digital outputs, which would then go into the 192). So, that means that I pretty much do need to use an optical connection if I want 8 channels going from the 002 into the 192.

Up until now, I've been using the ADAT I/O located on the 3rd removable bay on the 192, and always had the pops and clicks. I only just now tried using the Optical I/O located on the enclosure. I think the proper name for these ports are Optical (ADAT) [Encl]. When I did this and had the clock source of the 192 set to Internal, I still had the clicks, even when the 002 was set to accept external souce through SPDIF. But when I set the 192 souce to Optical (ADAT) and the 002 source to Internal, slaving the 192 to the 002, voila! I've got 8 digital I/O with no pops or clicks!

I'm happy!

Thanks again!

[Barnabas]

I'm happy!

Happy is good!!