This question is related to one of my older questions: Push to talk mic over music

I was thinking how to get rid of the mechanical action of the relay so I wanted to know if it is possible to drive a signal through a SSR (more exactly G3MB-202P DC5).

In the diagram below the main idea is that when the button is not pressed, the music is playing at maximum, and when the button is pressed, the music is lowered through the potentiometer, and at the same time the microphone amplifier is powered on. The expected output should be the mic volume higher than the music, and both mixed together.

7404 inverter is used because I need some kind of NO / NC relay which is not available for SSR.

The question is: is it possible to drive a sound signal through SSR? Will it be a plus or a minus compared to driving the signal through normal relays? enter image description here

After reading all the answers, some documentation and going to my local electronics shops I came to two available ICs: CD4066B & CD4016B. I believe they both work for my purpose, but I've only tried CD4066B following this diagram.

enter image description here

Works like a charm and It's exactly what I wanted :) Thanks!

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    \$\begingroup\$ Use analog switches instead. \$\endgroup\$ Jan 17 at 8:43
  • \$\begingroup\$ Something like MAX317/MAX318/MAX319 ? \$\endgroup\$ Jan 17 at 8:54
  • 1
    \$\begingroup\$ There are many analog switches for specifically audio applications. MAX4855 is an example. \$\endgroup\$ Jan 17 at 8:58
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    \$\begingroup\$ You might consider trying something that has been used for audio switching for decades, JFETs. Here's a link to start off with: community.element14.com/members-area/b/blog/posts/… \$\endgroup\$
    – GodJihyo
    Jan 17 at 15:00

2 Answers 2


It is possible, with a suitable SSR and suitable circuit, but not with that SSR and circuit.

Compared to a relay, SSR just has some ON resistance while a relay has very little. SSR likely switches faster and consumes less energy.

And there are likely better ways than SSRs to begin with, like analog muxes and switches.

And you already have a mechanical button, so should use a suitable mechanical button and circuit.

If I am not mistaken, all you need is two audio sources, two resistors that are suitably selected to provide the required mixing levels, and switch to either connect or disconnect the mic. What would these relays or SSRs or analog switches do differently if you already have a switch.

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    \$\begingroup\$ Please explain the downvote and I will fix my answer. \$\endgroup\$
    – Justme
    Jan 17 at 9:44
  • \$\begingroup\$ the SSR would get read of the popping noise when switching \$\endgroup\$ Jan 18 at 8:01
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    \$\begingroup\$ @CătălinaSîrbu What makes you think an SSR will remove the popping noise when switching? The SSR is just an ON/OFF switch just like a relay. If there is a pop due to the circuit design, it makes no difference if the switching is done by SSR, analogue switch/mux, relay, or mechanical pushbutton. If you want to get rid of pops, you need a better circuit, not a different switch. Your question was not about pops, but about using SSR. \$\endgroup\$
    – Justme
    Jan 18 at 9:07

Absolutely not. The G3MB-202P (it would have helped us if you had linked to the datasheet in your OP) is a triac output, so suitable for power switching only.

There are opto-isolators with FET outputs that would be suitable. Do a parametric search for those on Digikey or the like.

If you don't need the opto-isolation, then search for analog switches.

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    \$\begingroup\$ If not for frequency reasons alone, the holding current is 0.1 A. The crossover distorsion would be substantial. \$\endgroup\$
    – winny
    Jan 17 at 9:43

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