Opto MOSFET relay switching module

[marcelomd]

Hi,
I just want to share something I did:





When developing my 2 channel preamp I needed (I think) to switch both input and output of each channel at the same time. Plus indicator LEDs. A 3PDT was not enough.

After some discussion, I came up with this thing. It finally came from JLC and it works just as intended.

This switcher module:
- Uses a pair of TLP240A to switch a channel in or out.
- uses the good old 4049-based flip-flop from R.G.
- Is pretty much instantaneous and there`s no audible click.
- There`s also an input and output buffer to even things out.

Things to improve:
- Since I have buffers, maybe I only need to switch the input or output;
- For the same reason, I think I can omit the anti-pop resistors and RF filters from the channel inputs.
- Add some filtering to +V and feed the channels from there.

Anyway, there you go. Thanks for all the help.