Yep that's the one. Just a few days ago I snagged a couple Symetrix SX202's of Pohaku. I had purchased a 528e--and was looking for more channels of the same sound without all the 528's extras.
And in the course of that transaction, Pohaku's educating me a bit on Symetrix, and tells me about the 501 for bass. I'm doing more and more with bass (though primarily a guitarist) and thought I'd keep my eyes open for one. Well one found me a day later.
Go figure...