Does anyone have experience with Bohlender Grabener RD 75 ribbon transducers?

@atmasphere -- thanks for the info; they're being sold by someone in Santa Ana, CA, who apparently inherited several (that had never been used) from his uncle.  I listened to them, and they sounded good, but would have to be paired with other speakers to cover the low mids and lows, so I passed. If anyone is interested, they should check craigslist in the greater LA area.

BG isn't in business anymore and the drivers have failure problems associated with tears in the diaphragm. If you have a set that works people are looking for them to replaced failed units.

I owned an pair for a few hours.  Hope this helps