Quad ESL63

[ppppenguin]

I don't think floating is justified here. The environment isn't really hostile. I've certainly used audio transformers to get me out of trouble in the past. Alas I didn't have anything comparable for video back then. It's not funny when "earth" at each end of a video co-ax has several volts of 50Hz with the capability of putting amps through the screen of the cable. Anyway, that's way OT for this thread.

I've looked at electronically balanced floating outputs. We did them at Michael Cox Electronics in the early 1980s. Not my design but I remember them as hairy. Then the SST chips came out and they just seemed to work.

To get more drive I could replace the output TL071 with a 5534 though it would need compensation as it isn't unity gain stable. Or bodge in half a 5532. Need to check that the fairly high bias current won't give grief.

I don't think there's anywhere to put XLRs on a 34, much as I like using XLRs.

Another factor to chuck in the mix is playing 78s. I can set the tone controls and filters on the 33 to give decent results. The 34, quite understandably, doesn't have that kind of filtering. The right answer would be to build a phono pre-amp, with switched RIAA and other EQ, and feed line level to the preamp.

All these things are possible. It's a matter of how much trouble I want to go to.