Hi Rich,
Okie dokie and here we go.
Answers...
Yep, each part is a layer. A phrase is made up of parts/layers.
Layer volumes are set via instrument and looper input gain on a general level and finger 'attack' on a minor adjustment level.
Phrase volume is set by looper output and amplifier settings.
A layer can be deleted due to a mistake, or incorrect volume, or even just because you don't like it via the 'handy dandy' Undo/Redo function on both the RC-20 and RC-50. This feature is good for only the last layer you ummm...'lay down'. For example, if you make a five layer phrase and 'blow' layer five, you can redo layer five. If you lay down layer five and like layer five, but are then dissatisfied with layer four, or three, or two, or one for that matter, you're stuck with it. Then you would have to rebuild from scratch. To summarize, you can only redo the last layer you 'lay down' on both the RC-20 and RC-50.
You can set up/lay down *only one phrase* at a time on the RC-20. You can have multiple phrases by saving them, but you can only 'call up' one phrase at a time (similar to songs on a CD, one song at a time).
Blather...
The above is a pretty good analogy by the way (CD songs) and how I approach my 'stuff'. I have a setting for rhythm and tempo saved to a song title. Then when I play, I select the song I want, fire it up and begin layering down with my bad self.
The RC-50 allows text input to title your phrases. The RC-20 only saves your phrases to a numbered bank. In other words, you have to remember what song number one is and what song number two is etc with the RC-20.
The RC-50 is also different from the RC-20 because it has three phrase capability. In this instance you can play all three at once, or in combination like phrase one and phrase two, or phrase one and phrase three, or phrase two and phrase three, as you see fit and what meets your need/application for the tune. (Remembering of course, each phrase can have multiple parts/layers.)
Sooo...
The RC-20 has only one phrase at a time and is about half the price of the RC-50.
The RC-50 has up to three phrases at a time and costs about $500.
They both have the 'handy dandy' Redo/Undo feature.
The RC-50 is stereo with almost double the record time of the RC-20. This time can also be extended by running it in mono instead of stereo, which doubles the record time (40 something minutes iirc). The RC-20 is mono.
The RC-50 allows text input.
The RC-20 doesn't support text input.
I think this covers everything. If not, I'll be around and try to clean this up some more. I hope it's getting closer to what type of information you're looking for.
As an aside, have you considered ordering from an online store being as how you live in the booinies? Delivery to your door and usually 30 days to try it out. A lot of online stores also have discounts on equipment that has been ordered and returned for various reasons such as, someone finds it doesn't meet their needs and they return it in like new condition. I mentioned earlier I initially had the RC-20XL. I returned it when I found it didn't meet my needs and upgraded to the RC-50 no questions. I got my synth as a return from someone who found it didn't meet their needs. I think it was about a 10% discount. Something to think about.
Nuff for this one. Time to stretch again.
Have you figured out I'm a yakker yet?
Bestest,
Kimberly