Tim E's Jawari with Drones

[Taylor]

I like Tim's idea a lot, but if you wanted to get a little closer to the way drone strings work, delay lines rather than oscillators would get you closer. Delays with really short times (below 30ms) and with high feedback will actually react to the notes you play. If you play the note to which the delay is tuned, it will resonate quite a bit. If you play a fifth of that note or the same note in a different octave, it will resonate a bit less.

Unfortunately there's no 50 cent chip that has 4 audio delay lines with clocks, so implementing this will necessarily be more complicated than 40106 oscillators. You could get 3 tunable delay lines with an FV1 (and many more delays if you tuned them in the software but didn't allow for realtime tuning) or one per PT2399.

Another direction of course would be to use a spring reverb circuit, and drive a bunch of strings instead springs - one by a few people recently and by the Ondes Martenot as Rick said in his above post from 2009.

[pinkjimiphoton]

i have a weird old "folk harp" someone gave me, it has 12 strings, so i figure maybe i'll mount a driver on it and make it into a "tuned reverb" one day...maybe even with piezos under the strings.

i agree, delay would work better.

i'd love ot build this thing tho, but not all of tim's designs work out...i have yet to bet a wobbletron to work, tho i did build a magnavibe that was kinda based on it.

[Taylor]

I recall now that Top Top actually built a string resonator like that - not sure how to find the thread but the info is somewhere around here. It has some good info on what kind of transducers he used to vibrate the strings.

[DougH]

so,...did anyone ever actually try this? seems to me, it would sound more like fuzzy bagpipes...

That's my thought too. These are oscillators so they are not going to sound like guitar strings at all, sympathetic or otherwise. It will sound more like a primitive synthesizer backing up your octave-y "sitar" sound from your guitar.

As to why no one's built it- not the typical chipset in a guitar pedal builders bench stock for one. More complex and no guarantee of it sounding like anything you'd expect, for another. It's more of an experimental conceptual idea for exploration than a finished ready-to-build pedal schematic.

[marmora]

Always been a fan of Tim Escobedo's Jawari circuit. I built one for a friend years ago and have always wanted a "deluxe" version for myself. I looked at the info Tim posted about adding sympathetic drones that trigger when you play, but I got lazy and added a mixer and a dual drone oscillator from Beavis Audio. The drones are switchable, so you can add them as you please. They don't sound as sitar-like as I would prefer (a speed control and/or an envelope would help), perhaps a bit "digital", but it's unique box that doubles as a stand alone oscillator.

[DougH]

I recall now that Top Top actually built a string resonator like that - not sure how to find the thread but the info is somewhere around here. It has some good info on what kind of transducers he used to vibrate the strings.

I built a diy sustainer with a small speaker driver a few yrs ago. Should be easy enough to hook that up to a separate guitar on a stand, plugged into another amp, with the strings tuned however you want. Kind of brute force but it should work. All kinds of possibilities with fx and so forth too.

Amazing how many time I try to envision building a dedicated circuit for something, only to realize I already have all the building blocks...