Well, after much experimentation, and sadly little help from this board (what's up guys?), here are my results.

First off, MOTU 828 FW and Windows don't get along, at all. They recommend downgrading to SP1 for better stability. Give me a break MOTU.

The USB version has problems. First off, 256K Minimum beffer? Are you kidding me? Then, about three time a day, major stutter while recording. About 2 seconds. Useless.

Anyway, to accomplish the above mentioned trick, it requires putting out SMPTE LTC while the "tape" is running. Vegas and the MOTU don't jibe like that.

THis added with the fact that none of the plugins that come with Vegas support sidechaining, I was going to try the trick using good 'ol analog gear, but with no SMPTE output, even that won't work.

So I'm still open to suggestions, as I am ordering an M-Audio 1814 to see if the drivers will work better, but it won't be a slick due to the lack of TC out of the machine.

A work around I may consider is printing a square wave and dropping that in a track, then using analog gear with sidechains to accomplish the task.

Whew!

Sadly, there is no standard for side chaining with DX or VST plugins.

There we some suggestions using some specially crafted techniques and some very specific plugins to accomplish something close to true side chaining.

A Vegas user here - Pipeline - has had some success. Perhaps he can chime in on his approach.

Most of the solutions I have seen involve specific VST plugins used in a particular way from with in Neundo/Cubase. These particular approachs wont work in Vegas.

I am not sure I follow what you want to do with SMPTE or what issues you are having with the MOTU.

I run a MOTU 896 all the time and it works very nicely at 128 sample latency. The 828 can be a bit flakey, but I have never heard of 256 K buffer sizes!!!!! Yikes!

Peter

As long as the track to be sidechained is mono, its really not too bad.

Send that track to a buss, send the control track to a buss, making sure its a good deal louder than the track to be controlled.

Put your plugin in, and go to town, the louder track will spell when the gate opens or the compressor squishes

Download gpan ( its free, part of the trial for Gsonic stereo enhancer, but gpan remains after the trial is over) http://shareit1.element5.com/programs.html?productid=143329&language=English

use gpan to send only the controlled track to the output of the buss

For further reading http://members.cox.net/pipelineaudio/the_bonker.htm

for a gate example

and

http://www.sonymediasoftware.com/forums/ShowMessage.asp?MessageID=424869

for a ducker example

Anyone try this one yet, I haven't had the chance.
http://www.twistedlemon.nl/site/index.php?option=com_content&task=view&id=19&Itemid=32

On the SMPTE thing.

This is an ancient trick for listen talkback mics. It goes back to the 70s and 2" tape, which is why it's freaking me out that no program can simply do this out of the box, and modifying them to do it is such a pain. I have pulled it off in both Pro Tools and Nuendo, although Pro Tools was easily twice as easy.

The old Way:

Stripe the last track with SMPTE (track 24 on 2")
Plug in a mic in the control room
Patch in a compressor on the mic.
Set the compressor to a very high ratio, fast attack, and fairly quick release.
Patch the SMPTE Output into the Key in of the compressor.
Flip the switch for "use Key input" or sidechain or whatever the compressor calls it.
Mix the output of the compressor to the headphone mix.

Now, when the tape is stopped, the listen mic is audible. When the tape is rolling, for either playback or recording, the SMPTE will trigger the compressor, and effectively turn the listen mic off.

You can mult the smpte output to sidchain a listen mic in various rooms as well, but it is a good idea to put another compressor to smooth out the sound, especially if dealing with drummers. That is what SSL and other consoles have built-in.

So, IF I could have the SMPTE out patched into an input on the 828, routed to such a scheme, the same thing can be accomplished.

Another hack for PT is printing a squarewave and making a track for that. Route that track to a compressor on an Aux input being fed by a listen mic.

In PT, I have a template made with all the stuff ready to go. I can import session data and insert the entire rig into any session in seconds.

On the 256K Buffer thing. That was for the USB version which I guess just started shipping. I am sending this one back from the screws loose on the inside (nice MOTU). I couldn't even get the FW to work at all. I guess I'm not the only one as there is a message board I found through unicornation.com that is just there for getting PCs to work with the 828FW. Bottom line, use SP1.

This free sidechain compressor works in many VST hosts (I'm using it
in Vegas 6):

http://student-kmt.hku.nl/~jorn0/sidekick/
http://www.twistedlemon.nl/

It works for me, and I'd recommend it at this price!

What TwistedLemon.nl's product does is to levitate a 4 channel virtual
bus consisting of any stereo channel that you desire. Any of these can
be used to duck down another channel that the plug-in is subsequently
assigned to. There is also the exact opposite effect at your disposal
where silence on the sidechain can suppress the stereo track it is
applied to until the signal level returns. fwiw to me ;)

If that is at all confusing, the developer does have his own
description on his website and in the help gadget inside the VST plug-in.

What I did to get mine to work:-

I popped the DLL plug into the appropriate plug-in folder for Vegas
(preferences VST shows you the primary and secondary search path, you
need to do a refresh to hook new additions in).

I started a fresh project and dropped two AV tracks into this session.

I dropped the Sidekick plug onto the track filter controls on the
audio part of the voice-over track (on the left hand side area rather
than dropping the filter on a clip). This assigned the first channel
(alpha) to tee out to the plug-ins private bus ["sending audio to
virtual channel alpha"]. I left this track in the default bypass mode
as it would be the side chain and only needed to influence the ducking
of the audio bed. As far as I can see, none of the sliders serve any
purpose for the sidechain track as you are just making the signal
available to the library for use somewhere else.

I'll now describe what I did to the track I wanted to add the
compressor-level control to.....

Again, in the same Vegas session, I applied the Sidekick plugin to the
whole audio track on the music-bed track. I ignored the fact that this
track was also being thrown out to the sidekick library as virtual
channel "beta". I de-selected bypass (as I wanted to influence this
track with this plug-in). With ducking selected, I highlighted "alpha"
as the virtual channel to use (to squelch with). The ~-50dB of
threshold that I chose seemed to be the depth of control dished out
rather than the detection level for the sidechain. Attack and release
probably depend on the nature of the piece. I emulated what I think I
hear on the radio for this. ~80ms of attack and ~40ms of release
smoothness.

I'm glad to say that Vegas let me do this and watch the DV in realtime
(the video track wasn't in need of work).

This free plug-in is stated as being fully functional in Cubase,
Nuendo, Logic RPC Pro amongst others. BTW: I've read that Logic has a
sidechain compressor (perhaps you need platinum) but Apple are about
to sundown these products. [NB there is a warning about some
quirkiness with Vegas on the TwistedLemon website - I closed and
re-opened my first few projects without any trouble].


You probably don't need all this guff described, but it might save you
5 minutes if you've followed my turn of phrase and can remember it for
when you try it for yourself.