Tri-Vibe Minus 1 Plus !

Started by Aph, October 18, 2018, 06:27:05 PM

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Aph

Here's a slight modification to runoffgroove's Tri-Vibe Phaser... just add one more chip to get another two stages! Also, I just wanted the Swirl and Vibe modes, not the Whirl. So, Tri-Vibe Minus 1 Plus, means "Tri-Vibe circuitry, minus one mode, plus more stages". I did, however, find that the vibrato I liked needed a little direct sound, hence 200K for R19.
Of course, you can eliminate this resistor, or just wire it as the original Tri-Vibe with a center-off switch.
I wanted just a little more output, so R23 is 51K. However, I'm a tweaker, so that wasn't good enough. I ended up putting a 100K trimmer in place of R23. As you can see from the photo, I soldered pin 2 to pin 3 of the trimmer and then soldered pin 1 and pin 3 to the PCB pads for R23. From now on, if the circuit doesn't have an external output level control, I'm going to design my boards with output trimmers!
C8 and C9 deserve to be played with. It sounds fine with the values in the schematic (1n5 for both), but I actually ended up changing C8 to 3n3.
I socketed C8 and C9 for future experimentation. (The soundclips were recorded with C8 and C9 both at 1n5).
That's about it. I do have a few PCB's I'd sell for $6 each (that includes shipping). But, please look at the pics. This is partially a surface mount board (SMD). The resistors are 1/8 watt, through hole. I would say this is not for beginners.
The original circuit can be found at http://www.runoffgroove.com/
Soundclips: https://soundcloud.com/collector1989/tri-vibe-minus-1-plus





ayayay!

Very nice.  I am building the original on my breadboard currently.  Question for you:  The LED off pin 8 of 1C3C, is that to indicate the LFO rate? 
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Aph

Quote from: ayayay! on October 19, 2018, 10:46:24 AM
Question for you:  The LED off pin 8 of 1C3C, is that to indicate the LFO rate?

Yes. I also use it as my effect-on indicator. It's hard off and on because it's from the square wave output, so at slow speeds if you just momentarily glance down it may seem the effect is off if you catch it in it's off state!