Greg Mayman wrote in a message to Jasen Betts:

 -=> Jasen Betts said to Greg Mayman
 -=> about "IMAGE FILES" on 12-19-03  20:26.....

 JB> Or a triac driver like MOC2031, basically an optocooupler, but the
 JB> output stage is like a 400V/100mA triac (or silicon bilateral switch)

 GM> Some years ago (30 years?) I saw some optos with FETs in the output
 GM> that acted as opto controlled variable resistors and they could be
 GM> used for AC control.

I know that there's a whole mess of different kinds of optos out there, 
and I haven't looked at what there was in quite a while.  Do you happen to
recall who made them?

 GM> According to the specs we should have been able to use them as
 GM> audio level controls, but we found they had a most peculiar type of
 GM> distortion at low levels.

I would imagine so.  A little bias should fix that,  maybe?

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