REVERB WITHOUT ONBOARD DSP

Why not add the reverb inside Sonar?

Many singers (including yours truly) get a better performance when they hear reverb in the headphones while singing. Of course, you'll always get a better final result by adding reverb later, in the box. But it's nice to monitor with reverb while tracking.
 
Even the best do it:

 
Another solution, if your audio interface supports it, is to use an effects loop within the interface. Unfortunately, it's one of the few features the Focusrite lacks, and one of the few features I miss from my old MOTU. Interfaces with a built-in effects loop is even better than having integrated effects because you can insert anything you like into the loop. There's no latency and the effect doesn't have to be recorded. Lacking such a feature you can still go old-school and dedicate a channel, as described by the OP.
 
 

Hello Jeff, with your 18i20 you should be able to monitor fx inside sonar without noticeable latency.
What drivers for the 18i20 you have installed?
What buffer size are you setting in the 18i20 software?
 
I have mine at 32 samples when recording and can't hear any latency at all, even with 64 samples I can record vocals and sometimes guitar thru amplitube and sounds very good.
I have the Scarlett MixControl 1.9b12 with Focusrite USB2 Drivers 3.2.2

Hey, thanks for the advice gentlemen. I'll have to see what my settings are. Don't  believe I'm as low as yours Sonico. Just remember an echo along with the reverb.
 
AntMan, I haven't tried your suggestion either, but you both may be correct.
 
Sorry it took me so long to respond. I had surgery and in bed now for a few weeks. Much appreciated!
I love the setup now

I used to monitor reverb by routing my vocal tracks to a bus with a send knob.
this was only for monitoring purposes. sonar is not printing it.
then I started realizing, the reverb setting I wanted was all set up and easy.
so I just put that in each track in the FX bin.
made a track template, that's my vocal track preset.
 
but a few years back I switched to using Delay instead on my vocal tracks (just for monitoring purposes).
a very fast delay, almost double sounding. really thickens the monitor mix up.
 
a few things can happen with this scenario though.
After a while one can be fooled in to thinking this monitor sound should be included in the mix.
hel if it sounds good while recording it, it must better when mixing it right ?
not really. don't fall in to that category. before the days of DAWs, I printed a lot of FX to tape.
I ruined many a good tracks that way.