Digital to Digital Tracking and mixing

[gl3ny]

I know proper analogue to digital recording is based upon the calibration of A/D convertors. Meaning that if I record a 0dBVU signal through my convertors into my daw I should be tracking at -18dBfs (my A/D convertor calibration) on a 24bit system.
My question is, what is the digital to digital equivilent if any? Is there an optimun gain stage for setting my soft synths?

I have been tracking digitally between 2 computers and applying the same strategy as analogue, keeping my meters around -18dBfs. Is there any point to this and does it really matter if I track digital to digital at -18dBfs? By applying an analogue to digital style gain staging strategy, my soft synth outputs have to be set at an extremely low volume setting within the plugin (with the output computer mixer fader at unity) to acheive a -18dBfs reading in my recording daw.
Am i doing this right, I'm looking for technical answers to this please?

[FeatheredSerpent]

There are no analogue stages to consider and you have total control of the dynamics at source so no, it doesn't matter.
(This is assuming you are streaming the soft synth audio via a digital connection, which you are implying, I think!).

A lot of people have experienced a favourable difference when running softsynths at a higher sample rate though, so you should try having the source machine set to 96k for example, and record that audio in.

If you don't want your recording machine set at 96k, then you'll have to convert the sample rate down using something like Voxengo R8 Brain.
But, you'll have to render the v.i., not record in real time.

Otherwise, run the softsynths at the higher sample rate and send out via analogue, perhaps through some sort of cheeky line-driver (I use a vtb-1 but only have one of them - drag) and then in to your 'tape machine' rig, which will take you back to observing sensible and appropriate input levels again

What's the rationale behind feeding digital sources in this way, is it a slave machine running cpu hungry plugs? (Just curious).

[gl3ny]

Yes that’s right.

Originally Posted by FeatheredSerpent

A lot of people have experienced a favourable difference when running softsynths at a higher sample rate though, so you should try having the source machine set to 96k for example, and record that audio in.

That’s not an option for me as my hardware is limited to 48k and I don’t really feel the need to run my plugins run @ 96k and rerecord them back in as analogue. That sounds like a lot of work to me and will considerably decrease workflow.

Originally Posted by FeatheredSerpent

What's the rationale behind feeding digital sources in this way, is it a slave machine running cpu hungry plugs? (Just curious).

And again yes that’s right. The rational is to spread the load of processing power and increase workflow. The softsynth/sequencer computer has an RME RayDAT HDSPe and is slaved to a loaded protools TDM system with a 24ch pro control. Both the master and slave computers can access apogee convertors for recording analogue. By feeding 32 tracks digitally from slave to master I don’t ever have to record those tracks if I don’t want to and can keep them forever midi. Instead, I just monitor them through the PT system and get to use all the TDM plugins at the same time.

My apogee convertors are calibrated at -18dBfs, so I track analog @ -18dBfs. The DIGITAL gain structure to track at -18dBfs looks like this:

Slave computer plugin = low > Slave Computer Mixer = Fader @ unity > optical transfer to PT system. I adjust the pluggin output level to achieve -18dBfs the PT meters.

The softsynth pluggin output is set very low to achieve a -18dBfs at the PT meters. One advantage I see in doing this is that all my levels whether tracking analog or digital are relatively the same at the mix stage.

So my question is, should I track the softsynth plugins at -18dBfs and is there any technical advantage or disadvantage to this? Will I be loosing anything with the quality at the mix stage with such low settings at the plugin?