I have a good answer for you, as I recently investigated to see if it was still worth using NLS since I use Scheps Omni Channel on every track.
If you run a 100hz or 1khz sine wav through NLS you can see the harmonics it produces if you use something like PAZ Analyzer (or Voxengo Span which is free, and higher resolution.) Note that it helps to expand the range down to -144db when evaluating harmonic distortion because sometimes plugins to low-level changes which you won’t see if your analyzer cuts off at 90db or something.
When you evaluate the harmonic distortion in NLS you’ll see that yes, all three consoles are different, and every channel is a little different as well. Does it matter in that specific regard? That’s questionable, because harmonic distortion varies based on your input signal. So sound already varies.
However, if you look at the PHASE and balance, you’ll see that NLS also adds individual variation in those aspects, too… And that’s part of why a mix through NLS can sound “wider” — because some of the channels actually alter your panning and phase a little, and those little additions add up!
You don’t get that individual variation in Omni Channel, obviously…
What you DO get, though, is harmonic distortion.
You can get it through Saturation in the preamp. Even or Odd. (Heavy is strange and I can’t explain what it’s doing.) The saturation in NLS, though, is a combination of even AND odd.
But here’s what many people do not know:
You get NLS-like harmonic distortion if you engage the OPT or FET compressor… Even before compression! Just by turning it on you get the equivalent of an NLS channel turned up to about 6 if I remember right. (!) You don’t even have to dial in compression for this harmonic distortion to occur.
It is SIMILAR to NLS’s harmonic distortion. Not the same, but similar.
You get harmonic distortion with the VCA compressor, too, but LESS – it’s a much cleaner compression, it only happens when you compress. You don’t get it just by turning it on.
The bottom line is, I turned on the FET compressor in my default setting and I use it on every channel. It’s close enough and it speeds up my workflow… but I don’t get the subtle panning/phase variation that you can get through NLS. This ensures I’m always getting that by default.
Does that mean you don’t need NLS? No, it just means get Scheps Omni Channel first! =)
I would love to see another iteration of Scheps Omni Channel with the addition of per-channel variation. Plugin Alliance offers that with their “TMT”, but I prefer Waves’s offerings overall and that’s why I’m here. (I should note that when I evaluated “TMT” the randomization was nice, but it was subtle compared to NLS. Since NLS wasn’t just random, but based on real specific channels in actual mixers – some of the channels are practically broken, which is actually very cool! You don’t get that with TMT.)
Anyhow, hopefully that answers your question. Definitely learn to analyze running sine waves and pink noise through your plugins (and phase analysis) to see what they’re doing!! It definitely helps to know.
For example, if you use a bunch of analog emulation plugins back to back it’s going to stack the effect. So in a case like that you might want to use RComp when you need an additional compressor because it actually doesn’t color the sound at all, etc…