I built the original Condor along with a headphone amp for late night jamming/pedal testing.
I couldn't get a clean tone from the Condor with the J201 and my humbuckers, unless I played softly or rolled back the guitar volume.
After trying different jfets and biasing, I decided to make some changes:
1. More headroom - converted the input gain stage to a Jack Orman basic buffer.
2. Added a gain stage after the notch filter - converted U1A to a 2x to 100x gain stage with feedback clipping diodes as described here 3. Used the Marshall response values per the Condor build notes.
Now it has much more clean headroom, and the new gain control goes from clean to quite a bit of soft clipping, which is nice when I just want to plug straight in and play for a few minutes without having to hook up another pedal.
And pedals sound much, much better running through this modified Condor rather than straight into the headphone amp.
1978 Gibson Les Paul Standard, Cherry Sunburst, Nickel Tone Zone & Air Norton Pickups, Sweet 16 wiring