an idea for a stompbox. any help?

[hoppock]

I have bought a walco accu-tuner...it is a metal box which, when plugged in, emits a single syne wave.  there is a selector switch which chooses between an A (440.00 Hz) and E (349.23 Hz)...you're supposed to plug it into your amp to tune your guitar to the note

I want to plug this into my Z Vex Seek Wah (the second picture) which is a lo-fi sequencer (sequences of 4, 6, or 8)...so it's sort of like a background instrument.  my problem is that all i can get this set-up to do is play 1 note, in a sequence so that I can play over it...it doesn't sound bad as a drone as long as the song stays in the Key of E.  I would REALLY like to be able to choose the note manually, though, hopefully with my foot, and switch notes while playing another instrument.  the selector switch is really basic (it's actually so bad that even if it don't bend it, I'll need to replace this switch).  the only other switch is the On/Off switch.

anyone have an idea of how this could be bent so that I could control the note with my foot and quickly switch between a range of notes?

What would be ideal would be a simple selector switch, maybe a metal box with a stomp switch, which would switch between two notes...or a series of stomp switches which, when stomped, would shut off the last note and move to the next note.

any clues?  does this sort of thing already exist?

matthew

[Ansil]

yes it does exist. a basic 555timer to create a pitch and use a old volume pedal to step through the tones.

[smoguzbenjamin]

The 555 won't make a sine wave though, but somewhere in between a sine and triangle wave. It doesn't sound bad though

[Paul Perry (Frostwave)]

...or a series of stomp switches which, when stomped, would shut off the last note and move to the next note.
any clues?  does this sort of thing already exist?
matthew

The analog synth DIY guys have "step sequencers", typically an 8 stage counter that drives a multiplexer chip to pick one of eight control voltages (set by pots). The output voltage goes to a Voltage Controlled Oscillator, and there you are.

A rougher way to do it would be to have a series of stopm switches that switch in and out a pot each, the pot (wired as a variable resistor) going to a simple oscillator.
Plus, if you put two switcheds ON at once, you get another resistance altogether  

[hoppock]

just interested in the idea of using the 555 timer and the volume pedal to step through the tones.  how does this volume pedal work?  do you have a model that you suggest?  I have a tone generator that works fairly well...but would an old volume pedal work for actually changing the note?  

i like the series of stomp switches connected to a simple oscillators idea...I'm trying to work with what i've got.  

so, i have a simple tone generator (the walco accu-tuner), which synthesizes a basic E.  i have the z vex seek wah which sequences in sets of 4, 6, or 8 (this is all the sequencing i really want)...now i just need something in between the to to shift the pitch, hopefully controlled by foot and easy to use.

[smoguzbenjamin]

All you need is a volume pedal enclosure and a 555 set up as an oscillator.