Chris Stelloh have been playing around with Jürgen Haible Wasp CV Filter and sent me two verified layouts..
In hi sown words:
I had a chance to build up that LM13700 version of the Wasp Filter and found that using a much different value of potentiometer for the cutoff control made for a better filter sweep.
This one is also verified. It contains a level pot that cuts or boosts the CV level. The oscillation switch implements the modifications that people have come up with for the Doepfer A-124 - which is a module that is basically a wasp. Albeit with some minor part value changes, as well as a HEAVILY modified CV and frequency/cutoff section.
Hey everyone! I drew these layouts using most of another drawing I found on a Tagboard forum thread, done by a user named Alex. I made some changes - mostly to the distortion switch - and got his version going using the 13700 chips that are slightly more available than the more expensive 3080 reissues. The bottom layout with the oscillation switch uses feedback mods suggested by Doepfer and also by Andy at Cytomic. This noisier version is definitely suited to "hands on" tweaking as opposed to guitar playing.
ReplyDeleteThank you!
ReplyDeleteI built one years ago using a different layout, and it sounds really great
You are most welcome. For anyone interested - I tested a mod to the distortion switch that is so stupid simple I'm going to file it under "how did I NOT try this WAY earlier"... if you want to get rid of the distortion toggle and replace it with a blend knob, it's really easy:
ReplyDeleteGet a B10k dual gang potentiometer. I wanted the blend to go from clean to distorted so I soldered lugs 1 and 4 together (taking the place of 3+6 on the switch) connect lugs 2 and 5 of the dual pot to the same connections that go to lugs 2 and 5 of the switch. Then take the wire from "dist SW 1" and connect it to lug 3 of the pot. Connect "dist SW 4" to lug 6 of the pot. The result is an even and usable clean-to-dirt blend knob.