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Topic: Electric Guitar Pickup switching (Read 1 time) previous topic - next topic

gratefulfrog

Hi!
I am a relative newbie here. 

My project requires being able to route audio signals from the 12 pickup coils of an electric guitar.  In other words, I need to create some kind of switching network that can send or not the signal generated by each pickup coil along a wire.  The Arduino will select to let signal through or not.

I was thinking of using relays, but I have no idea if they will add noise or alter the signals, nor do I know which relays to get?

Or maybe there are other better components?

My questions:

  • What component to use as a digitally controlled audio signal switch?

  • Any other suggestions?



Thanks for this great forum!
Ciao,
Bob

Boffin1

you could use 3 quad analog switches  CD4066
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dc42

The best answer depends on a number of factors:

1. How do you want the pickups to be connected when they are all active? In series, in parallel, or each one to a separate amplifier input?

2. What is the resistance of each pickup?

3. Can we safely assume that the peak signal voltage from the pickups is not more than +/- 0.5V ?

3 x CD4066 quad switch ICs may be suitable, but their on-resistance is 270 ohms typical @ 5V and 25C, which may be too high in some configurations (e.g. if you connect the pickups in series and use the switches to short out the ones you want to disable). Another possibility is 12 x 2N7000 mosfets, which have a muhch lower on-resistance.
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gratefulfrog

We can assume around 6 Kohm resistance per coil.

There is no fixed network layout, I want to be able to play around, selecting series/parallel, in phase/out of phase, for all pairs of coils. Yes, that means a big network if it were to be fully deployed, but at first at least I may reduce the complexity.

Output voltage is on the order of +:- 0.125V.

The on-resistance should be as low as possible, like a normal mechanical switch.

I have no way of judging what is the best, or even a good starting point, so I will just take all advice and try it out!

Thanks to everyone - more advice is always welcome!
Ciao,
Bob

Boffin1

dc42s suggestion of 2N7000 is good, and they are cheap.

If you just want to experiment with the idea with 3 chips, you can get an idea of what you want to do, we have no idea of what music you play,  heaven forbid we suggest something that introduces distortion :-)
With my mobile phone I can call people and talk to them -  how smart can you get ?

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