Amp footswitch

[fryingpan]

I need to switch four DG419 switches (I could get away with two, but I want to minimise noise), one for a channel switch and one to engage FX. My idea (I haven't seen any stuff online, I'm trying to come up with it myself) is:

+15V, regulated -> two voltage dividers to get +3Vish and 10mA current (so, let's say, a 600 ohm resistor and a 150 ohm one), each in parallel with a cap -> cable (tip for one, ring for the other) to an SPST switch each -> in the ON position, an LED + a diode to bring down the voltage below 0.8V. The middle point of the voltage divider goes to the control pin of the switch.

Would it work?

[vigilante397]

Alright, there's a bit to unpack here. But we'll start with the easy stuff. DG419 is not a latching switch, it's the CMOS equivalent to a momentary switch, meaning as soon as the input voltage is removed the switch will go back to it's previous state. The simplest way to deal with that is to use a latching footswitch to provide the control voltage to the DG419. If you want an LED you can put one between the IN pin and ground, so anytime you apply voltage to your DG419 the LED lights up, that's what I do when I use relay switching. I would recommend putting a pull-down (probably 100k or so) on the IN pin to make sure the switch is deactivated and not left floating when it's supposed to be off.

If you look at the datasheet it also says "Note 1: Signals on S, D, or IN exceeding V+ or V- are clamped by internal diodes" so you don't need to drop your 15V down to 3V, it will get clamped internally, so you don't need to drop it with your voltage dividers.

Honest question: what does the DG419 give you that a relay wouldn't (besides lower current draw)?

[fryingpan]

Alright, there's a bit to unpack here. But we'll start with the easy stuff. DG419 is not a latching switch, it's the CMOS equivalent to a momentary switch, meaning as soon as the input voltage is removed the switch will go back to it's previous state. The simplest way to deal with that is to use a latching footswitch to provide the control voltage to the DG419. If you want an LED you can put one between the IN pin and ground, so anytime you apply voltage to your DG419 the LED lights up, that's what I do when I use relay switching. I would recommend putting a pull-down (probably 100k or so) on the IN pin to make sure the switch is deactivated and not left floating when it's supposed to be off.

If you look at the datasheet it also says "Note 1: Signals on S, D, or IN exceeding V+ or V- are clamped by internal diodes" so you don't need to drop your 15V down to 3V, it will get clamped internally, so you don't need to drop it with your voltage dividers.

Honest question: what does the DG419 give you that a relay wouldn't (besides lower current draw)?

Well, you don't have to deal with relay bouncing.