Help with a pedal idea (in and out of phase step sequencer...?)

[sevenisthenumber]

I have a Telecaster wired with a 4 way switch. Pretty standard thing.
Positions:
bridge / bridge+neck out of phase / neck / bridge+neck in phase.

If you strum a chord or anything really and then flip the switch back and forth through all the pickup positions it sounds awesome. Almost like a step flter or something.... Any ideas on how to do this with a pedal? Maybe a tremolo type thing but instead of Trem it changes phases at a set speed?

[Pablo1234]

I would say that it would be fairly easy with a microcontroler, like a basic stamp and driveing a bunch of j111's on and off with as many twin t filters as you may want. Have the microcontroller switch the tin t filters out in a step sequence and whallah you have several notch filters at difrent ranges. Would be a low component board also, you could also use a comb filter and use a bunch of switches also. If you wanted it somother like fadeing into steps insted of just steping you could use VCR's it vary the gain of each comb filter fading in and out on difrent LFO's, could get awfully interesting.

[Taylor]

Very simple. Just make a Vanishing Point and point the LED that it lights at the LDRs of an optical phaser like the 4MS Phaseur Fleur. A large circuit, but more achievable than microcontroller stuff for most DIYers.

[Pablo1234]

I don't know that I would agree about the microprocessors, Basic stamps from parallax are extremely easy to use, and not much is used for the external circuitry. I would suggest looking into them for switching circuits be for using hard wired switches any day of the week. The Board of Education is a fully contained small programing board with a small breadboard built right onto it, and the documentation and possibilities is nearly endless. Currently I use mine for a test setup, I genorate 3 AC voltage signals for testing at known frequencies. I simply use the darlington array chip, a cap, a resistor and poof I have a sine wave genorator output on just on of the 16 I/O pins. Then I have 2 spst switches I use to multiplex an off, 800Hz, 1100Hz, and 3kHz signal selection. So I am using 2 pins to select my output based on what pins are pulled low. I could also suggest them for Programmable LFO's in a plethora of ways. Much more sophisticated then using a Oscillating circuit or a 555 timer with a multitude of caps and resistors. All easily changeable via usb at any point in time.

If you think its is too complicated but your in need of some basic programability their forums are top notch for support from the local comunity and employees as long as you have a clear idea of what you are trying to attempt. Also their documentation of the basics all the way to very specific applications is extremely well done and plentiful.

[Taylor]

Well, I'm sure it's simple compared to big boy digital stuff, but compared to a single 4017 and a couple of components, and no knowledge of code necessary, it's a couple notches higher in the chain of complexity.

[Pablo1234]

Well you may be right, but I still believe 3 days with one and a small desire to test one might change your mind. The basic stamp code is almost ridiculously easy, and like I said the documentation is abundant and not in the least overwhelming.

[sevenisthenumber]

how could i delve into something like this... I have built tons of pedals and even designed a few... Mostly overdrizes, fuzz, booster, etc... Same old simple stuff. I would love to get to something like this and understand why its doing what its doing.

[Taylor]

Do you mean how your guitar switch is working? Or how the effects we suggested to replicate it work?

In the case of my suggestion, it is basically 2 projects combined. The Vanishing Point (linked above) is like a switch that steps from one "value" to another every so often. You can make it change between values very quickly or very slowly. At the end of a circuit, it lights up an LED. The pots control how much that LED is lit at each step, so for example it can go "dark-bright-very bright-kinda dark...". Then you aim this LED at the LDR (light dependent resistor) of a phaser like the 4MS Phaseur Fleur (also linked above). That circuit changes its amount of phase shift depending on how much light it sees on its LDR. So when the VP's LED is bright, there is a lot of phase shift, and when it's dark there is little (or it may be the other way around) and in between you get different variations.

The cool thing about this is that you don't need to modify either circuit really. Just point the LED at the LDRs, and it should work pretty well.

Also note that if you want it to be the exact effect that you get with your guitar switch, you could probably design something to go in your guitar and actually switch your pickups over and over automatically. But if you just want something close, the phaser will be pretty close.

[e45tg4t3]

maybe you could try it with an analog multiplexer like the CD4051/52/53 and ancounter like CD4060(this one has build in oscillator)...

Benny