I was browsing Joe Davisson's site of old stuff and discovered this:



How should I read the triangles with circles on the end? Are they op-amps or something?

(sorry 'bout the large pic...) :lol:

Here you go:
The triangles are inverters, this chip has 6 of them.

http://microelectron.free.fr/DataSheets/Cmos/cd4049.pdf

I've got a bunch of these, thanks for bringing this project up, post your results, please

It's a 4049 inverter chip. It looks like opamps because of the diodes, but it's really an oscillator with clipping to provide a square wave, which is then converted to some "sawtooth" and "sine" approximations. This circuit will probably work alright, but I would have a look at the EA tremolo and trade the 4049 oscillator for the EA's oscillator, use an MPF102 or J201 control FET, and a transistor stage as shown on the EA schematic. The 2N7000's are very noisy. Oh, and it's really a tremolo, not a vibrato. Got my terms messed up... I'll try to update this sometime, it's probably one of the simpler ways to get all three waveforms...

I just built the EA from Runoff Groove's perf layout, and it is a killer trem.
I have a Voodoo Labs Tremolo(pretty much the industry standard), and the EA is better IMHO. Yowza!

Regards

RDV

I'm going to build the EA tremolo After I finish my generalguitargadgets.com mini mixer, the EA trem is next.

But I was thinking, if I placed diodes in the feedback path of Q3 (of the EA trem), I could create a quasi square wave LFO output...
Or should I take the output of the LFO, add a tranny stage with diodes in the feedback path with a trimpot for the "volume" of the LFO?

Oh, gringo, my results'll be on my site when I have them. Keep a lookout for a "Mos-Vibe build report" topic :twisted: