The link above to Riders of the Purple Sage refers to two old bands from the 1930's through the early 1950's. I suspect neither of these used Alembics. The correct reference should be to the New Riders of the Purple Sage, the Grateful Dead spinoff band that was formed in 1969. IIRC, founding member singer/guitarist/songwriter John Marmaduke Dawson used an Alembic. I believe Dave Torbert, the bassist following a brief stint by Phil Lesh, may have also.
Bill, tgo