360 Systems 20/20 "tremolo"
I am very fortunate to have a window of access to all manner of rare gear at the moment, including a full E-Mu modular system (!) and my favorite ring modulator of the pack, the 360 Systems 20/20 Frequency Shifter. Playing with the two earlier today, I managed to coax a downright beautiful tremolo out of the 20/20, which, sure, tremolo from a ring mod is nothing new-- set the modulating oscillator to sub audio and there you go-- but here's a bit of a twist:
The 20/20 has three outs: Low, Ring Modulation and High (the sum and difference have their own outputs (!)). Patching all three into channels of the mixer (with Low and High panned hard left and right) and playing their levels along with the dry signal, I was able to get these sorts of sounds:
360 Systems Frequency Shifter tremolo by Peter Speer
(the E-Mu photo = the drone patch you're listening to.)