Sliding 808 Portamento Glides in Reaper with the Free VST TX16Wx
THE STEPS! Here they are.
Step 1. Instantiate TX16Wx as an instrument on a new Reaper track - open the Regions view and drag your 808 sample in.
Step 2. Under the Regions piano roll, set the Root Note to how your 808 is tuned (check with ReaTune and if it doesn't recognize a note, open ReaPitch and pitch the 808 up by an octave until ReaTune detects a pitch).
Step 3. Open the Waves tab. Right click the waveform - "Loop" - "New Loop". The loop will stretch the whole length of the waveform - grab the side handles and shrink the loop/drag and drop the loop section to your desired range.
Step 4. Zoom in on the waveform (+ - next to the horizontal scroll bar) and use the Start and End arrows on the loops tab under the waveform to cycle through successive zero-crossing points. Note - make sure you are looping a set of complete cycles - each cycle is a combined upswing and downswing (like in a sine wave).
Step 5. To make the loop work, do 2 things:
A) right click the loop in the waveform - go to "loop" - "Assign loop"; and
B) click the circular arrow button above the waveform that looks like a refresh button - this enables looping playback.
Step 6. To enable legato gliding, do 2 things:
A)click on the Groups tab, and enable "Legato" or "Mono" under the Poly column; and
B) click on the Sounds tab, and under the AEG (Amplitude Envelope Generator) turn up the Glide knob to taste (I like ~300ms)
Optional:
Turn up the Release knob in the AEG until you get a desired fade out of the sample when the note is released.
IMPORTANT: to get the gliding behavior in your midi piano roll, overlap your midi notes slightly. If you don't, TX16Wx won't do proper gliding. Unfortunate, but that is what I noticed.