Craig Anderton's Ring mod. This ring mod sounds good. It has a little bit of carrier wave bleed thru like most ring mods do. Nothing too distracting thou. I added a tone switch and a pitch switch to this circuit. I think they were both suggested mods in the EPFM book.
SUPER TONE CONTROL
Envelope switch connections
This phaser sounds pretty cool but I wouldn't call it lush or anything. Compared to my Ross 8 stage phaser, well, it doesn't compare. It is capable of other interesting high resonant modulation type sounds though. This is one of the more complex circuits to build. It has the most parts and uses four vactrols or opto couplers. It calls for CLM6000's in the book. These are non existent these days. Some people have luck building there own vactrols with LED's & Photocell's. I bought some opto couplers from electronics goldmine. You can buy them individually or get a lot of untested ones. I went for the lot and hand picked ones with similar resistance values.
This is the envelope follower circuit found near the back of the book. This is like an add on that works in conjunction with the other effects. This circuit also uses the opto couplers mentioned in the Phase shifter text. If you go back and look at the pictures of the Tone control front panel , and the front panel of the Phase shifter, you'll see the envelope switches. These switches activate the envelope for these effects. When activated on the tone control it acts like an auto filter type effect. On the Phaser it's suppose to add a swell type effect. The envelope works great on the tone control and not so well with the Phaser.
This is the one effect that didn't come from the EPFM book but it is a Craig Anderton design. I actually stripped down this circuit. The tank I used has a long decay and a dark tone for a spring reverb. The parts I removed seem to muffle the sound further. The reverb still sounds kinda dark but in a neat way, I think.
Some extra pics of the enclosure, reverb tank, and PSU. The PSU is pretty much the MFOS wall wort PSU with 9v regulators.
Hope you enjoyed the pics and info.