VTM phasing bug?

[cyjanopan]

Turn off the wow and flutter and there shouldn't be any phasing

[The Warmth]

Tried that. Didn't work. When I send from the main drum bus to the parallel bus it's fine, but not from individual tracks to the parallel.

[RKrizman]

Originally Posted by The Warmth

Bought this a few days ago, so I've got v 1.0.1.1. I've got a phasing issue when using parallel compression. I've got all my drum tracks running through one instance of VTM on a bus (sounds great). Then sending varying amounts of the individual drum tracks to a parallel bus. When I turn up the parallel bus, I hear weird phasing going on which disappears as soon as I disable VTM on the main drum bus. It's as if VTM is being processed a few samples late?

Not sure how logic handles delay compensation, but perhaps it's the plugin's latency on the one bus causing the problem. Try instantiating it on the other bus and bypass it, so the other bus has the same amount of latency.

-R

[edva]

There is a setting in Logic to make the busses have delay compensation ("ALL", I believe). Not sure if that's your issue, but worth checking.

[psycho_monkey]

I've replied to your Slate forum thread as well - I notice it in PT as well. It's enough to cause a sample to flam with the main track, and annoyingly, it the delay doesn't happen in bypass - which means you can't use the whole "copy plugin over and bypass it" trick to match the latencies.

I think the plugin is reporting it's latency incorrectly....

[dawnfirst]

I have the same issue.
From time to time, even with delay comp turned on (and set to maximum samples) I am getting phasing issues on drums.

i find if I take off all the tape plugs and then put them on again it sometimes fixes it. It's weird though as I checked the delay of all of the tracks and they were well below the minumum PT allows in it's delay compensation.

[psycho_monkey]

Originally Posted by dawnfirst

I have the same issue.
From time to time, even with delay comp turned on (and set to maximum samples) I am getting phasing issues on drums.

i find if I take off all the tape plugs and then put them on again it sometimes fixes it. It's weird though as I checked the delay of all of the tracks and they were well below the minumum PT allows in it's delay compensation.

I'm very convinced it's a bug...something gets confused with reporting the delay.

[The Warmth]

Originally Posted by psycho_monkey

I'm very convinced it's a bug...something gets confused with reporting the delay.

That's what thought... But the weirdest thing is happening to me as we speak - I'm suddenly getting latency while using a bus in Logic regardless of VTM being on or not. I've disabled all my plugins and have drums all coming out of one bus then sent to the parallel bus. When I enable the parallel, phasing happens

Tried latency compensation. Not working. Only happens in this project - my only one with VTM - and none of my others.

[psycho_monkey]

Originally Posted by The Warmth

That's what thought... But the weirdest thing is happening to me as we speak - I'm suddenly getting latency while using a bus in Logic regardless of VTM being on or not. I've disabled all my plugins and have drums all coming out of one bus then sent to the parallel bus. When I enable the parallel, phasing happens

Tried latency compensation. Not working. Only happens in this project - my only one with VTM - and none of my others.

I find it comes and goes - if you import tracks it sometimes screws things up. Might just be the old PT ADC bug going on...

[Pucks]

Get rid of the VTM on the Drum Bus and give every drum track it's own VTM. Makes more sense if you want to get the 70's sound. It saves a big deal of PSU consumption in Cubase. (don't know if that will be the case with your DAW)

Or:

Get rid of the VTM on the Drum Bus, and patch both the parallel compression and drum busses to a new bus and put a VTM on the insert over there.

[narcoman]

the VTM does have a lot of latency - and maybe its not reporting it correctly. One way to test it !!

I'll get back to you

[psycho_monkey]

Originally Posted by Pucks

Get rid of the VTM on the Drum Bus and give every drum track it's own VTM. Makes more sense if you want to get the 70's sound. It saves a big deal of PSU consumption in Cubase. (don't know if that will be the case with your DAW)

Surely that could mean running 10 or more instances of VTM - surely that's more power not less?

That is also the way I'm doing things, and occasionally having problems (which are fixed by restarting PT it would appear). I agree that paralleling with a tape sim isn't exactly conventional.

[Pucks]

Originally Posted by psycho_monkey

Surely that could mean running 10 or more instances of VTM - surely that's more power not less?

8 VTM's on single (stereo) channels leave me more DSP power than one on a bus. (in a production of over 24 channels)

[psycho_monkey]

Originally Posted by Pucks

8 VTM's on single (stereo) channels leave me more DSP power than one on a bus. (in a production of over 24 channels)

That's weird! oh well - if it does it does! Maybe if the audio is being bussed there's something to do with real time processing involved..who knows. It doesn't work like that in pro tools.

[The Warmth]

Seen your posts on the Slate site, Psycho Monkey. I haven't had a chance to upload all the info they require yet. Let's hope this gets sorted soon! For all others, here's the link with an explanation .::SLATEDIGITAL::. | View topic - Phasing issue

The issue seems to go beyond that. I'm surprised no one else had reported this issue.

[stella645]

Originally Posted by Pucks

8 VTM's on single (stereo) channels leave me more DSP power than one on a bus. (in a production of over 24 channels)

So glad you mentioned this....can't believe I hadn't worked it out myself.

Because VTM seemed so cpu heavy I stopped using it on channels and have been putting it on my groups only but I have still been disappointed how quickly my system's been running out of steam.

I just removed 6 VTM from my groups and inserted 29 on all channels and my asio meter has gone down over 10% and the mix sounds better to boot.

[RKrizman]

Odd. Of course, when you consider that this is TAPE emulation perhaps it's not designed to be used on an aux bus, but only on tracks that are actually recorded. You need console emulation for your buses, because they don't go to tape.

-R

[psycho_monkey]

Originally Posted by RKrizman

Odd. Of course, when you consider that this is TAPE emulation perhaps it's not designed to be used on an aux bus, but only on tracks that are actually recorded. You need console emulation for your buses, because they don't go to tape.

-R

I don't think the system cares what the program is trying to emulate - it's more to do with feeding audio sums in real time through an aux channel.

It might well be the case in PT - but like you say, I've never felt the need to put a tape sim on the bus (apart from with the mix buss). Occasionally I would if I'm summing 2 guitar mics ITB as if I'd done that on tracking...but usually no.

I'll try it when I feel the need!

[Hardtoe]

I have noticed some weird phasing in a similar mix situation in Ableton Live 8 as well....

Also, in Live, all channels that are bussed together need to be processed on the same core (I'm on an 8-core mac pro) so it can be beneficial CPU wise for me to load down the tracks instead of the busses as well.

[Sebastian]

Weird. Why would there be a CPU drop between busses and tracks? I'm going to have to try this and see if I can get better performance.

[The Warmth]

Using 8 individual instances of VTM on drums instead of on a drum bus doesn't really change my CPU performance In Logic. As suggested by the Slate team, turning down the buffer size really helped with the phasing