# channel selector using an IC and momentary switch?

Joined Apr 15, 2016
8
I'm working on a guitar effect stomp box that uses diode clipping. I would like to use multiple arrangements of diodes to achieve different clipping sounds (4 minimum, 8 maximum arrangements.) I would like to use a momentary switch to cycle through all the arrangements in a sequence. Im sure this can be achieved utilizing an IC and/or transistor circuit but I don't know what would work best. Any help is appreciated!

#### GopherT

Joined Nov 23, 2012
8,009
I'm working on a guitar effect stomp box that uses diode clipping. I would like to use multiple arrangements of diodes to achieve different clipping sounds (4 minimum, 8 maximum arrangements.) I would like to use a momentary switch to cycle through all the arrangements in a sequence. Im sure this can be achieved utilizing an IC and/or transistor circuit but I don't know what would work best. Any help is appreciated!
Can you sketch out the various configurations you need? Just pencil paper and snap a photo. We don't need fancy.

Joined Apr 15, 2016
8
Can you sketch out the various configurations you need? Just pencil paper and snap a photo. We don't need fancy.

Joined Apr 15, 2016
8
Basically, 1 input that would be a signal in from the effect, and at least four switchable outputs. I suspect I could use a designated voltage and a momentary switch to trigger the circuit to sequencer through outputs? Am I too far off?

#### absf

Joined Dec 29, 2010
1,968
Yes, you could use half of a 4 to 1 multiplexer like 4052 and a 2 bit binary counter as the A/B address select of the channel. The button is connected to the input of the counter.

Allen

#### crutschow

Joined Mar 14, 2008
34,697
A couple observations if you use a counter and a multiplexer:

Note that multiplexer signal voltage limits typically go between the plus and minus power supplies.
What power supply voltages do you have?

The switch to index the counter must have a debounce circuit to avoid multiple counts for each switch press.

#### Alec_t

Joined Sep 17, 2013
14,382
Wouldn't you also need some way to know which output is currently active, and/or a way to 'reset the counter to zero'?

#### GopherT

Joined Nov 23, 2012
8,009
The 4 inputs of a CD4066 bilateral analog switch could be connected and the chip used as a multiplexer.

Then you need a second multiplexer (e.g. 74151) to trigger the switches for each switch of the CD4066.

Then you need a counter to rotate through each channel on the 74151

And finally, a debounced switch for you to pulse the trigger the counter.

Issues would be the DC bias because the analog signal has to be between the + and - voltage supply of the CD4066 chip. For simplicity, that a hip allows a +9 to -9 volts if you have a split power supply (or even two 9 V batteries in series with ground being the node between the two batteries.

Joined Apr 15, 2016
8
Awesome, thanks for the ideas. This gives me a good place to start. Dual power supply isn't a problem and I can build the circuit to accommodate voltages needed.

Joined Apr 15, 2016
8
Wouldn't you also need some way to know which output is currently active, and/or a way to 'reset the counter to zero'?
I had thought about LEDs for channel indication, but decided it was probably more work than it was worth.

#### GopherT

Joined Nov 23, 2012
8,009
I had thought about LEDs for channel indication, but decided it was probably more work than it was worth.
An LED on each output of the 74HC151 will tell you which channel you are using.