

Boosters are not buffers! While it is possible to make a booster that also provides a buffering action, the vast majority of the boosters commercially available ready-made or kits, do not have the proper design to be buffers.

The AMZ Dr. Quack is an updated and improved version of the E-H Dr. Envelope Filter pedal. Here are a few notes to help anyone building this circuit. Please refer to the complete schematic on this site for reference.
The opamp of choice would be the 4558, which I used in building the prototype. The 5532 has low input impedance but good output drive, and should work as well. The 4559 would also be good. The circuit should be fairly insensitive to the opamp choice.
I actually came across this chart of heavy metal band names while doing some legitimate marketing research for my day job. It is interesting and gave me a couple of chuckles:
Heavy Metal Band Names Flow Chart
If you are searching for a name for your new band, check out the AMZ Band Names page.
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Jack Orman has been involved in FX design and construction since the mid-1970s.