Discrete BBD/tube phaser

[Mike I.]

Doug (and list),
A tube-based phaser is an intriguing idea. A possibility would be to 
make a tube version of the Univibe - use LDR's plus tubes instead 
of LDR's plus discrete transistors/op amps. The allpass stages in the 
Univibe are interesting, since they use a simple phase splitter circuit 
to provide differential drive to the rest of the allpass stage, instead 
of using an op amp with differential inputs. Sort of backwards to the 
usual method. Maybe use a triode phase-splitter, and replace the 
Darlington-connected transistor with a cathode-follower.
Mike