integrating analog devices with Digi 002

[greggoad]

Hello.

I am new to the forum, but have been using LE for three years or so.

I am trying to figure out how to use analog gear for specific functions with the Digi 002.

If I wanted to take tracks or entire mixes that already exist digitally in pro tools, and then send them through a device like an analog compressor for reamping or mastering purposes and then bring them back into pro tools -- how do I do this.

I have experimented using the digi 002's outputs, running them through the analog device and then sending them back into the digi 002's inputs.

I am experiencing latency problems, and in thinking about it, I am degrading the quality of my signal by doing this.

I have read of people using digi 002 and something like a Manley Vari - mu compressor to master. What do I need to do to preserve my signal quality and to avoid latency?



Do i need to run an A/D or D/A converter out of the ADAT in/out?


Is this application possible with LE and a digi 002?

Could you explain the Signal Path that I would use?



thanks very much for your help.

Greg

[albee1952]

First, read the section of the manula that describes setting up inserts. You will have latency as you are dealing with 2 stages of conversion(D>A on the way out of the 002 and A>D on the way back in) coupled with your buffer setting. There is no way around that but for mastering, its a non-issue(you end up with a stereo audio file that is processed and recorded back into protools. As it is the final mix, it does not need to align with the other audio in the session. Now if you are trying to use analog processing on some audio in a mix, then you need to nudge the audio earlier in the timeline so it ends up at the correct time once it passes thru everything. Using external converters in and out of the lightpipe ports works just fine with all the same details as described(but may sound better if you use higher quality converters like Appogee).

To recap, you can maintain the audio quality by using good converters and analog processing gear(but cheap stuff will probably make your audio worse than staying "in the box"). Latency is unavoidable unless the DAW has automatic latency compensation(protools HD and Nuendo have it, but LE does not). If you don't readup on the inserts, just pick 2 outputs(not main L&R) to send audio out, and pick 2 inputs to return audio(but set the new track's output to main L&R so it does not feed back to the external chain.

[greggoad]

Thanks a lot.

That's pretty much what I figured.

If I do the above, either nudging the newly recorded file, or simply use the process for mastering, will the signal be degraded a lot, or is this still a viable way do do things until I get a higher end converter?

I want the Playback engine to be at 1024 samples, correct? That will affect audio that's coming out of sends right?

Thanks again.

Greg

[daeron80]

I have a web page about mixing latencies. Calculating them is not quite as simple or obvious as one might think.
http://elvenminstrel.com/recording/p...auxlatency.htm

If you use the 002 converters, your sound will often lose a little something. Sometimes noticeable, sometimes not. Not always critical. Kick, snare, and bass will probably suffer the most. Vocals often pass through no problem. In any event, it won't sound bad. It just might not sound quite as good as it did, so the external process needs to be so good that it's worth the trade.

I used to do some of that, but I now prefer tracking at higher bit and sample rates and using good plugins. Get the fxpansion VST-RTAS converter and you'll have access to a variety of amazing ones for free, and a world of them for cheap.

[DigiTechSupt]

Daeron80 - When did you do those calculations? I'm curious, because I know that, at least in 7.4, Pro Tools compensates for the A/D/A latencies.

I just had a situation where I had to test this and doing a loopback test, the audio came back in perfectly aligned with the original.

[daeron80]

That's good news. I did the tests in 2006, I believe. I assumed they were a hardware limitation of the 002. I'm still on 7.3 both at work and at home. I'll update my pages to state that the data may not apply to 7.4+.

[daeron80]

OK, updated the mixing latencies page. Is there any reason to suppose that tracking latencies have changed with 7.4?

[DigiTechSupt]

I don't know if they changed with 7.4 or with an earlier version - I just know that, at some point, A/D/A latencies were being compensated for.

I'm going to try to find out which version this was implemented in...