Don't bother with the other opamp, the TL082 is fine. It's just a more hifi version of the TL072.
If I read you correctly, the wet pot is now working as it should, it's just weak overall, is this correct? Since you've sourced your own parts, it's a bit harder to troubleshoot this one than if we'd known all the components, but I assume you've checked that all parts are correct values etc.
Yes I checked all the components for the correct value, and the wet pot does exactly what it's supposed to do. Actually all the pots function normally as they should.
From your description, I would first check that the input buffer is working ok. It may be a wrong value resistor, a bad solder point, a short to ground here somewhere; you need to rule that out first. Ideally an audioprobe would help you here, to check what your clean signal sounds like at various places after the input stage, but we can try it without. (Be careful with the volume of your amp as you do this, or use another box inbetween that limits the signal). As a quick first test, make a jumper connecting pin 7 to pin 1 on the opamp; you should now hear your crisp clean signal, and it should be louder than in bypass. Confirmed?
If no, your input buffer isn't working correctly.
Nope, very distorted sounding. - downright fuzztone distortion.
If yes lets try this; if you have a spare 10k/12k resistor, use it as a jumper between pin 7 and pin 2 now - this should sound the same as the prior test, loud and clear. Confirmed?
If no, your output buffer isn't working. Lets get these two out of the way first.
OK, here's what I did:
I tried both tests even though it failed the first one.
With a plain jumper (clipped off lead from a used resistor), it was not clean. Sounded like a low volume fuzz box. Not really a bad fuzz sound either, but nowhere near what this thing is supposed to do. There was also no delay produced this way.
I then tested it with nothing to confirm I hadn't killed anything. Back to the original problem, so no harm done.
I then tested it with a 10k resistor (measured 9.87k on my DMM) across pins 2 & 7 of the TL082. Now, the volume bypassed is only slightly more than engaged. The engaged tone loses a lot of bass yet though. Echos sound the same as the initial signal.
I appreciate the help - a lot!