cool easyvibe/univibe idea

[lightningfingers]

I've heard a lot of good things about controlling the speed of a univibe with a foot rocker-could the same kind of effect be acheived using an envelope follower to modulate the speed pot? it could be something simple like an LDR in parallel w/ the pot being modulated by an LED, and then add a switch to invert the control signal...

[Torchy]

Hello my name is paul and Im an easyvibeaholic ....

Use the LFO from the EA trem, using the pulsing LED to change the LDR resistance. Series/Parallel resistors across the LDR to set limits for the speed rate. Putting the LDR on a switch to swap between manual speed and LFO vari-speed...something like that ? Or just have it permanently in LFO mode, just a stomp switch and a depth control. Call it the NanoVibe  

Ive got two easyvibes to box up. May try this out this weekend ....

[Arno van der Heijden]

Not a new idea. The Vibe part of the Foxrox Captain Coconut does something similar.

www.foxroxelectronics.com

[lightningfingers]

heres what i was thinking, put a simple envelope follower off the input buffer, and then put a 1K pot in series with the LED, your "sensitivity" control. At minimum, the LED won't light at all, if you use an LDR that goes to about 10M in the dark, it wont affect the speed pot at all and you have a normal phaser. At maximum it will go reeeel fast then to real slow and everything in between.

However I think it will definately need an LDR that has a very high dark resistance or the speed controll will be affected...

[Mark Hammer]

The old Polyphase and Polyflange from Electro-Harmonix incorporated envelope control of LFO rate, and *possibly* modulation intensity (I forget, but one of you must know).

The thing to remember is that optimal modulation intensity and rate-of-change will vary with what it is you are using an envelope to control.  So, if I have a limiter that is intended to keep sharp transients from overloading my tape, amp, or speakers, I want envelope control that gets in there fast, does what it has to do, and buggers off just as fast.  If I had that sort of envelope-controlled influence over modulation rate, it would be a bloody nuisance.  You'd probably hear it as a brief irritating trill that interrupted a steady periodic sweep.  Not much use, really.    Likewise, even if I had if fade in and out more gradually,  I'd probably want just enough contrast in modulation rate to know that it had changed, but not so much as to feel like it was jerking me around here and there.

So, if you're going to do it, the ideal to aim for, in terms of usability, would be something that produces and envelope with an extended (though not "Slow Gear" speed) attack to the envelope and has a longish decay so that the change gradually eases back down.  Similarly, you'll want something that doesn't up the oscillation rate more than maybe 30% or so.  My guess, is that you're going to need some trimpots and experimentation with parallel resistances to achieve the desired balance.

[moosapotamus]

For starters... I'd take a look at how Tim implemented the envelope control in the Uglyface.

~ Charlie