HD Native/ HD IO gain/distortion issue. Help!

[tronnyjenkins]

I will try to keep this short but include all pertinent data.

Mac Pro Late 2009 12 Core 3.46
Tried using both Snow Leopard with PT10 and
High Sierra with PT Ultimate.
DSubs are going into +4.

We recently built a new desk and so therefore I had to change our patch bays around. We also upgraded our Pro Tools setup to Ultimate from 10HD. Before this, there were no issues.

What's happening:
inputs 1-8 seem to be clean and of a normal gain level.
inputs 9-16 are low gain and have distortion but all match.

Are there any software issues to check? Are there any known HD IO issues that might cause this? I of course am concerned that it is in a bank of 8 since those are the number of ins or outs on the interface itself.

Got a big drum session on Friday so panic mode starts now...

Help!

[tronnyjenkins]

Could it possibly be a bad Digilink cable?

[JFreak]

If you swap the cards from A to B and vice versa, does the problem follow?

[Darryl Ramm]

Originally Posted by tronnyjenkins

Could it possibly be a bad Digilink cable?

No. The problem seems analog, not digital.

[Darryl Ramm]

Originally Posted by JFreak

If you swap the cards from A to B and vice versa, does the problem follow?

^^^ yes. it’s likely either the AD cards or the cables feeding them (eg non balanced cables shorting pairs to ground etc.). Or maybe that group of preamp/preamp rack if coming from a single box/500 Rack etc. Swap the input cables (and so preamps attached to that) first. Crank up signal gen plugin to drive preamp or line inputs can make things lots easier to troubleshoot. Get out a multimeter and confirm the DB-25 cables are wired correctly/not wrong AES/EBU cables etc.

[albee1952]

Assuming this is an HD IO 16x16 analog? Open Setup>Hardware and verify that 9-16 inputs AND outputs are set to +4(or the same as 1-8). I would also try swapping the DB 25 connections to see if the problem follows the cable or remains with the IO(1-8 or 9-16).

Last thing(and really important), if you attempted(on purpose OR by mistake) to run UNbalanced signals, the manual states in bold letters that this will damage the unit if the cold side(the "-" of the balanced line) gets grounded(this could happen if you had DB25's routed to a 1/4" patchbay and connected with an unbalanced cable(TS instead of TRS).

[JFreak]

Originally Posted by albee1952

Last thing(and really important), if you attempted(on purpose OR by mistake) to run UNbalanced signals, the manual states in bold letters that this will damage the unit if the cold side(the "-" of the balanced line) gets grounded(this could happen if you had DB25's routed to a 1/4" patchbay and connected with an unbalanced cable(TS instead of TRS).

Should make damage channel by channel, not the entire card at once

[albee1952]

Originally Posted by JFreak

Should make damage channel by channel, not the entire card at once

Good point, unless the failure affects at a root level, like power supply regulation. I've actually never known anyone that has done it, but thought it might be worth a mention anyway