The Yamaha RA 100 is a unique rotating speaker from the 1980's. It was made for compact organs to get an authentic Leslie sound, but can used with any electronic instrument that you'd like. It's got a speakon external speaker output and RCA inputs. There's also a 1/4" remote output. It has two 12" speakers and also two rotating horns. It's a very easy to use amplifier and sounds quite good. The parameters it gives you to work with include knobs for volume, bass, treble, reverb, and tremolo speed. I've only used the RA 100 in the studio, but it would certainly be a nice thing to have live as well for your digital organ. I've used it with a Farfisa compact organ and for this it sounded fantastic. Even if you don't use the rotating speaker and just use it as an amplifier it sounds great. Having the two rotating horns however really make the RA 100 a cool speaker. I've seen a few speakers like this out there, but this is one of the only models that I've used and is definitely the best sounding one of it's kind. Unless you've got a preamp for a real Leslie speaker, I don't think you're going to find one quite as good as this. I don't know much background on the RA 100 and I'm not sure how easy it would be to get your hands on this as I've only used one the one that the studio owns. If I were a keyboard player with a digital organ, or even a guitar player looking to get creative with a rotating speaker, I'd consider the Yamaha RA 100 or something like it for live shows and in the studio as it really adds a certain quality that you miss out on with a digital Leslie simulator!