192 to HD I/O upgrade
 

Have just upgraded from a 192 to an HD I/O analog and could use a bit of help regarding the analog output.

With the 192 analog output I used an Avid DB25-TS +4Db/-10Db Padded Digisnake (MH094) to drop the output to -10Db and unbalance it. I'd like to continue to use this cable with the HD I/O rather than start opening the unit and changing the Hi/Lo jumper settings. Does anyone know any good reason to not do this as the DB25 pinouts are exactly the same on both units?


Many thanks.

Re: 192 to HD I/O upgrade
 

Pinouts are the same. This begs the question of why you need to lower the level and unbalance the outputs??

Re: 192 to HD I/O upgrade
 

To have the option of feeding the output into gear with a -10Db unbalanced input!



I'm a bit puzzled as to why you'd ask the question as I thought that might be somewhat obvious.

Re: 192 to HD I/O upgrade
 

If you want to be 100% sure, create a support case and ask Avid Support to confirm, but if memory serves me right you can use normal cable with Avid HD interface even if you connect to -10

It was the DigiDesign 192 that needed special cable to not fry the card, but that should have been fixed in the new version.

Again, double check with Avid Support.

Re: 192 to HD I/O upgrade
 

I'd dearly love to get an answer direct from Avid and that's the route I tried first.



I opened a case last Thursday and it's still showing as in the queue - and I pay Avid for a so-called 'support' contract!!!



The issue is both the unbalancing and the padding. The HD I/O has the option to change the internal jumpers for a -6Db pad but this involves removing the unit from the rack and opening the case whenever I need to change it rather than just swapping a cable.

Re: 192 to HD I/O upgrade
 

For both interfaces, the crucial thing is to NOT ground the cold side of the balanced line. I asked for 2 reasons: 1-because not everybody knows this stuff, and 2-because there still might be a better option(which I can't offer as I don't know what other gear you are connecting). I made a custom cable as I needed to feed unbalanced stereo inputs of a headphone amp(I needed 4 TRS lines with 2 outputs on tip and ring but unbalanced). Its also possible to connect balanced to unbalanced by floating the shield, connecting + to the tip and - to the case of an unbalanced connector(either RCA or quarter inch).

Re: 192 to HD I/O upgrade
 

if it takes too long, post your case number and we can escalate your concern

Re: 192 to HD I/O upgrade
 

Exactly.

If you do cables yourself, driving -10 should be using ground and hot pins only, not connecting hot and cold together. This is the most importan point, and which is why the original DigiDesign -10 cable ever existed.

If you do cables yourself, just use ground pin and hot pin, that will not harm anything. Same goes for AES/EBU to SPDIF connection by the way.

Short-circuit may fry the card, so with this kind of thinking you can avoid that.

Re: 192 to HD I/O upgrade
 

It is possible to use the MH094 cable with the HD I/O. Just had a very helpful reply from Maria in Avid support. I've posted below it to help anyone else with the same question:

"Your Digisnake MH094 should work connected to the default Analog Output + 4dBu (default Hi -option jumper) of the HD I/O to provide you the -10 dBV output.

If you would need a different output value, as you were reading on the manual you'd switch the jumper to Lo- output setting from -6 dB and if adjusting Trim pot for additional -4dB. (page 42) at the end you would have output to -24 dBu"