Dr Quack and Nurse Quacky Combo Schematic for Bass

[Ben Lyman]

I noticed the original Seamoon Funk Machine indicates a B50K sens pot, not sure about EHX Dr Q.
In the Dr. Quack, maybe Jack Orman used B100K with 47K across it to keep with the "most widely available components" theme.
Maybe ROG sort of mostly copied Jack's design for the Nurse Quacky and just left it like that.
Maybe I should have used a 50K sens pot but the 100K seems to work just fine.

I think the input buffer improves this circuit. Any thoughts on an output buffer?

[Kipper4]

Maybe just a bjt output buffer will do. Simple low parts.
Is it boxed already? How much room have you got on the pcb for an output buffer?
If it's boxed put a buffered bypass pedal after to see if it has the desired effect.
Orman is a good starting source or Gus....
It's a cracking job so far mate.

[Ben Lyman]

That's a great idea Rich. I'll put a buffer on a bypass box after it and pop it in and out to see how it reacts.

Right now, this pedal is going as is and it's really good. Certainly good enough for my friend who is only reimbursing me for the parts cost 

Just painted the box, switches are soldered and the whole thing is ready and waiting to go back in the box after the paint dries.

[Ben Lyman]

Finished ahead of schedule 

1992 Mexican P-Bass into pedal and 1976 Bassman w/1x12" Mesa Boogie cab

[rutabaga bob]

2 thumbs up, Ben!   

[Mark Hammer]

Swanky!!

[Ben Lyman]

Thanks guys! Sorry I'm not a bass player but I plan on getting my buddy to help me make a new vid when he comes over to get it 

[thermionix]

Your bass playing is just fine.  Pedal sounds killer, like a Bassballs but with more tonal options.

[duck_arse]

Your bass playing is just fine.  Pedal sounds killer, like a Bassballs but with more tonal options.

.... and a better name.

[Ben Lyman]

Thanks guys, this thing is so fun. I never thought about having an envelope filter before but now I want to make one for my guitar.
I suppose all I have to do is change those 2 10nF caps (my C9 and C10) back to 4.7nF and it's good to go for guitar, right?
Maybe slow the decay a bit more for swooshy chording.

[Kipper4]

Your R5 is the attack.
And R8 decay if you disregard the 25k pot paired to the transistor used as a variable resistance.
Take a look at some classic envelope detectors. You may even find some breakdowns of how it all works.
Mark hammer and a lot of other guys (Jon, Steven Giles, DA too many to name) are well versed and very willing to offer advice thankfully.
I'm glad you enjoyed making this.

[Mark Hammer]

For guitar, there are a few additional things to mull over (though not necessarily requiring mods).
Wah after fuzz and wah before fuzz each have their special charms.   Auto-wah after fuzz is somewhat hampered by the restricted dynamics imposed by the fuzz.  Having the filter hovering around a pivot-point,as opposed to travelling a broad distance, can have its charms, and sticking any filter aftersomething that generates more harmonic content makes the filtering action more evident.  But because you can't work the sweep quite as much with your picking as you can work a conventional wah with your foot, some may find that a little frustrating.

Going the other way, just like regular wahs, some distortions respond well to a filter placed ahead of them and others make you wonder if the wah is even on.  Same thing with a autowah.  Keep in mind the fault may be with the other pedal and not the autowah.  One should also keep in mind the need foran acceptably hot signal to push the clipping pedal hard enough.  Regular wahs can boost just a tad, and that may be all you really need.  Accomplishing that with your build may simply want a little more feedback resistance in the filter stage, and perhaps a complementary volume pot on the output for optimal level matching.  Keep in mind that since more gain in the filter tendstomove the sweep range downward, reverting back to .0047uf, but with more feedback resistance, will nudge your sweep range a little lower.  Maybe not such a terrible thing.  Just something to keep in mind.

[Ben Lyman]

Running through some more tones with my friend on bass

[jez79]

For guitar, there are a few additional things to mull over (though not necessarily requiring mods).
Wah after fuzz and wah before fuzz each have their special charms.   Auto-wah after fuzz is somewhat hampered by the restricted dynamics imposed by the fuzz.  Having the filter hovering around a pivot-point,as opposed to travelling a broad distance, can have its charms, and sticking any filter aftersomething that generates more harmonic content makes the filtering action more evident.  But because you can't work the sweep quite as much with your picking as you can work a conventional wah with your foot, some may find that a little frustrating.

I've had some success adding an fx loop after the input buffer, returning before the envelope.
The clean signal controls the envelope, but the filter is applied to the fx'd return.

[Mark Hammer]

Which is why the Q-Tron includes a send/return loop befoore the filter.