Two phasers tuned differently.
Got this scheme from a Elector magazine-87. The nice phase effect occurs at slow speed setting. Match therefore the J-fets closely.Adjust trimpot=250k for maximum amplitude modulation with minimum distorsion.All this can be done with your ears! Use metall-film resistors!
My version differs a little from the original. I use true bypass(with relay) instead of the digital/analog-4066 circuit (i don't like those!)
and i use the modification with depth control-2A shown in Text2.

The original schematic looks like this!
Here is the PCB !
Some aditional Text 1
Some more! Text2 with trimming procedure
Part list plus some remaining text.
Here's the zip covering everything!
Let us build!

Stellan