Let me first say the RFB02 designs are great! I have about 16 of them
If you need the snubbers or not depends on your choice of diodes. Some diodes give more RF noise than others.
Today, many use fast recovery diodes even for audio purposes.
I would say that the 3rd best diode choice is fast recovery diodes (FREDs), then as 2nd we have the fast soft recovery diodes, and on 1st place we have Schottky diodes (no recovery).
I use soft recovery diodes and Schottky diodes for all my own designs.
Whn I use Schottky diodes I do not use snubbers, and I have quit using the snubbers with soft recovery diodes.
You can also use the RFB02 as a base for filtering RF from the AC voltages from the transformers as I have done herehttp://instantboard.com/users/peranders/viewtopic.php?t=93