Tuned Drone effect - AX1G Korg alike

[alex frias]

Some years ago I've used a Korg AX1G small and cheap multeffects. The unit had few intersting thing on its effects algorythms.

One I really liked was the Drne. The parameters, if I remember well, was about to set the key and the drone volume. It reminds me of a Resonator effect on some 80's effects racks.

Anybody could indicate a path to achieve a similar effect as a discret diy project? Any clue will be welcome...

[R.G.]

555?

If you want it to simply go there, you'll need a top octave generator or a uC emulating a TOG. A uC could be programmed to read a 12-Pos switch and drone in that key easily enough.

I've looked at this for an electronic bagpipe setup.

[connie_c]

Craig andertons book, electronic projects for musicians, has a tuner reference pedal that creates a pitch at all 12 notes. Ive never built one and dont have the book handy but i think the tone the pedal creates is constant. into an octave circuit or a fuzz it might be an interesting way to create what your looking for.

[GREEN FUZ]

...I've looked at this for an electronic bagpipe setup.

What was this, some sort of sinister Ministry of Defence project?

[Taylor]

The resonator effect isn't a synthesized note, so the 555 wouldn't do this. The effect resonates at a certain frequency only when you play, and resonates especially loudly when you play a note at the resonance pitch.

What this is is a delay with a very short delay time (<50ms) with high feedback. By controlling the delay time, you change the resonance pitch. The more feedback, the more pronounced the drone pitch, until you get high enough that the drone note sounds even when you're not playing. Shorter delays times equal higher pitch.

[R.G.]

Oh. OK.

Part of the inherent evil/goodness duality in bagpipes is that the tone drones all the time. Different. I've never heard the "drone" on one of those.

What you're describing is a high-Q filter with a variable center frequency. It does exactly that. It's hard to get both high Q and flexible tuning on an analog filter and not have it break into oscillation though.

But you can try. The simple way is with a twin T filter and the resonance turned up. The more complex but more stable way is with a three- or four-opamp state variable filter or perhaps a ladder filter if you're liking synths. These could all theoretically do that. Tuning is an issue, though. Maybe a switched-capacitor filter would be a better way to do the tuned-part. I don't know how stable switched-cap filters are with near-oscillation resonance.

[alex frias]

Thanks for the replies. But the last one is closer to what I think about it.

I've tried something similar to Tim Escobedo Drones circuit, but it failed to achieve the right effect. well the effect I wish to achieve...

I think the resonator/drones sounds more like those Indian instruments with sympathetic strings and special buzz bridge (jawari) like sitars, swarangis and tambouras. than 555 based circuits.

I have a Dano with buzz bridge and when it is combined with that Drones effect at the right key, WOW, it's a trip to great inspiring moods.

Maybe a combination of a very short delay, high resonance and some filtering...

If I miserably fail to get it done, I still can buy a second Korg AX1g and put it bypassed externally with a mechanical switch.

[ashcat_lt]

I like the idea of the tuned delay thing through the tuned filter.  Then maybe a little "waveshaping".  You know, like distortion.  Probably not exactly what you're talking about, but it would be cool!

[DSV]

I once managed to get some weird drone effects through a delay (of a Zoom multi-effect unit). Delay was set around 20ms (with small variations, depending on the note you would like to obtain), high repeats and feedback. Unfortunately, that was some time ago, so I don't remember everything exactly. I'll try to find the settings though.

[alex frias]

i have some mulieffects units, but I can do something very interesting with them, I can't get THAT effect and tha what I realy want. Thanks for all suggestions, this is realy a great site with people with good will.

[Imhotepiii]

Basically I'm in the same boat as the original poster. My question is, is it unrealistic to think that I can repair the pedal. To replace the button switch beneath the pedal. Could I possibly get a switch from Radio Shack etc that would cycle through the effects again? Could I insert a switch that would atleast allow me to by pass the pedal when unneeded? The drone kicks ass on the korg AX1G and it has been an important part of the music we have been playing. Any advice would be appreciated as I know nothing about the effects...I just play.