Diy stereo Y spliter, with a switch

[JebemMajke]

Hello

I would like to make a y spliter with a switch. So it goes either a or b. Not both.

Input is stereo and 2 outputs are stereo.

This is an idea for my home recording studio. To switch between speakers and headphones. Output is from my pc's audio card, and than it goes into a Y box, and using a switch i could change where audio goes. No need for LED;s, just mechanics.

Now, i know i can do this with a 3pdt, latching switch, because there are 3 wires coming out, and 3 wires per each, headphones and/or speakers.

But I would like to do it with a dpdt, or even better spdt.

Could I have a common ground and than just switch between "left-right" headphones and "left-right" speakers? Or even better, "left-right" of both joined and just latching between grounds?

Any ideas?

[jez79]

Yes, common ground. Switch it with a dpdt

[Granny Gremlin]

But I would like to do it with a dpdt, or even better spdt.

Not possible with SPDT (if speaking of a single passive switch, with digital controller or relays behind it maybe).

Or even better, "left-right" of both joined and just latching between grounds?

This will effectively sum to mono.  Switching between grounds does nothing because a) the ground is already common (assuming consumer type sound card with headphone jack output) and b) even if separate L and R grounds, it's the signal you need to switch; the path to ground is (mostly) irrelevant, which is why you can have a common ground.

So assuming your soundcard output is on a headphone jack (1/4" or 3.5mm  TRS phone), then you can use a 2PDT; one pole each for Tip and Ring, joining all Sleeves (which is the common ground - all phone type stereo headphone connections use a common ground for both L and R) together unswitched. There is no significant cost savings between 2 and 3P switches (at least stomps) and some might argue for switching the ground.

If your speakers are consumer type comp speakers that's the end of it.  If one or more is a consumer hifi system, then you'll need a Y cable on that output (3.5mm headphone jack to 2 x RCA).  If either destinations are powered monitor or PA type things then things might get a tad more messy than that.

[JebemMajke]

Thank you both on your ideas.

I am not trying to save money, but to have the smallest switch possible. Because this switch is going inside my table. Very crazy idea

So i am not even thinking of using "traditional" 2pdt and 3pdt switches.

[PRR]

Ground switching on Stereo will "leak" the difference of Left and Right, giving a funny spaced-out sound instead of silence.

Unless you have some other ground path (often the case, through power systems), in which case ground switching either does nothing or introduces all the crap in your ground to the signal.

DPDT. Often as small/cheap as any other switch. Main limit in small-signal work is the lugs and handle-- you need to be able to solder to it and work it. Historically not worth making a switch smaller than that. (Today you can find microscopic lug switches but they may only come in bulk for robot assembly.)

If you are really tight on space, put a relay somewhere else, buffered with CMOS. Your activator could be two pins drilled into the table. Finger-resistance across the pins toggles a flip-flop for A or B. You can go to one fingertip size plate under plastic if you use capacitive or room-buzz sensing (kitchen under-cabinet lights sometimes have touch switch plates).

[tubegeek]

I am using the same style switch for a similar purpose as we speak. [I'm at the sound board right now ]

Mine is built into a 1" x 2" box with the appropriate pigtails coming out.

As stated above, switch L IN to either L OUT1 or L OUT 2, and switch R IN to either R OUT 1 or R OUT 2. Connect all the grounds together with no switching.