Hardware insert on master fader feeds back?

[KK Proffitt]

PT 6.3.3
5 card Accel
2 Gig MP G5
OS 10.3.3

Unless I'm missing something crucial, hardware inserts on master faders seem broken.

I set up my 2nd 192 interface in i/o setup "insert" as 5.1 for an XLogic Multichannel (analog) compressor. I inserted this on a multichannel master fader and the thing caused feedback at listenable levels. Am I misunderstanding something here? Shouldn't an insert be post fader on a master fader so that the output of the insert gets routed out the original signal path with the fader feeding the insert? I.E. signal path BACK to the insert is terminated from master fader out?

channel sum---->master fader signal path output---->xlogic------->192 out

Works this way for plug-in inserts, why not hw?



We worked around it by putting the XLogic on input and output i/o and routing channels to the XLogic and then setting an aux in coming from XLogic out which we routed to main outs.

If hw inserts on master faders feed back when you set them up as inserts on i/o, then how can you use hw inserts on a master fader?

[Russ M.]

It is possible that due to the electronicaly balanced i/o on the 192 if your hardware is not balanced that it can cause problems like that. I've even noticed cross talk between inputs that are not used/connected from another input... I hate the way it works but I have to deal with it even to the point of adding balancing circuits to the inputs and outputs of hardware..

[KK Proffitt]

It is possible that due to the electronicaly balanced i/o on the 192 if your hardware is not balanced that it can cause problems like that. I've even noticed cross talk between inputs that are not used/connected from another input... I hate the way it works but I have to deal with it even to the point of adding balancing circuits to the inputs and outputs of hardware..

Thanks for the info Russ. Unfortunately, that's not the case here. The SSL Multichannel Compressor is definitely balanced (and at 7 grand it had better be!).

I believe the problem is either a design flaw in the i/o inserts section or the master fader signal path...or both.

[doug_hti]

is it possible that you have a signal going out digitally on 1&2 simultaneously. I think that the 192i/os default setup will add a digital output on 1&2 along with analog 1&2...Sorry if you already know this, but under the hardware setup, you shouldn't see the "+" sign on any of the ouputs indicating multiple outs...
At least this happened to me with a reverb running in an out digitally creating a feed back loop...after I threw away preferences one time

[KK Proffitt]

is it possible that you have a signal going out digitally on 1&2 simultaneously. I think that the 192i/os default setup will add a digital output on 1&2 along with analog 1&2...Sorry if you already know this, but under the hardware setup, you shouldn't see the "+" sign on any of the ouputs indicating multiple outs...
At least this happened to me with a reverb running in an out digitally creating a feed back loop...after I threw away preferences one time

Thanks, Doug.

So, this was digital feedback that immediately became apparent on reboot after trashing prefs? If so, that's not the case here. Feedback occurs when increasing the main level of the XLogic which is on an insert of the master fader, so it should be the last thing in line and (according to me <g>) it shouldn't go anywhere except to the analog outputs on the 192.

My first 192 i/o is just the regular i/o for multichannel mixing. On the second, I had the XLogic assigned to 6 analog channels via i/o setup on the inserts page. I have the TC6000 assigned to 2 digital channels via input and output pages in i/o setup.

I trashed all sends to the TC and I didn't see any signal on the stereo aux return for the TC. The analog and digital paths should be separate, yes?

I do see your point, though. If your scenario is the one affecting my problem, analog channels, once selected in i/o setup inserts, shouldn't be available digitally.

Maybe I'm not understanding your point, but I can see the potential for a feedback loop if dig i goes directly to dig o....but it shouldn't on an insert. It should break signal path and route output down the channel. Yes?

[doug_hti]

yes, I got feedback, because the "hardware setup" defaulted to the main output putting out analog 1-2, as well as digital 1-2(which was going to a pcm81)...so even though you only see analog 1-2 on the session, it's duplicating that out to digital 1-2...so if you have the 6000 on digital, then there is a chance that this could happen...I believe it happened to me when I had a hardware insert over the master as well and I just heard more reverb...

but it sounds like it may very well NOT be the case, but it does sound like there is some sort of "mult" going on..I would just verify and go to "hardware setup" not the "i/o setup" and check the "output" section. And make sure there is not a "+" on any of the outputs, indicating the "mult"...

that is the only possible scenario I can see happening. good luck!!!

[KK Proffitt]

Thanks for the added info, Doug!

KK