Thoughts on this input selector PCB? How can I add volume control?

[alfa147x]

Questions about input selector

IY audio passive preamp

I'm trying to replicate this. Can someone help me understand this part:

This passive preamp use a 4-port, 3-position switch. All channels' ground signal is switched with the main signal. The grounds of each channel are isolated, therefore ground loops between equipments are eliminated. Also, the noise from one source cannot get into another.

Specifically the bolded portion. Do the ± go both to the 3 position switch from each input?

Thanks,
Alfa

 

[DF96]

You have two channels, each with a ground and a signal. That is four connections. You have four poles (he calls them ports) on your switch. I don't understand your question.

 

[alfa147x]

You have two channels, each with a ground and a signal. That is four connections. You have four poles (he calls them ports) on your switch. I don't understand your question.

Thanks that clears it up a bit more. So while the signal is being switched with the 3-position switch where does the ground connection get switched?

 

[DF96]

The same switch. You have four poles: two for signal, two for ground. So with a 3-way switch you can switch between three inputs. I still don't understand what is puzzling you. If switching the ground is too complicated then use a 2-pole switch and just switch the signal - as most people do.

General rule in DIY: if you don't understand it don't do it!

 

[alfa147x]

That makes sense. I would like to switch the ground as well. I'm drawing up plans at the moment. I want to switch the output between two options (headphone and power amp).

Thanks for the help!