Audio switch question

And, as often happens, I've found a possible answer to my question almost immediately after posting it.

The next two switches I looked at both mention "splitting the signal to either amplifiers or active speakers or a combination of the two". Assuming that's also true for other makes, then my idea will work.

Many Desktops have two audio outputs. One on the front and one on the back. Could save you a switch?

Thanks for the thought, but the convenience of a switch would be that I wouldn't need to keep plugging and unplugging each individual cable.

Many thanks for that extremely detailed answer, but as I stated earlier, I would much prefer the convenience of a switch over the need to keep plugging and unplugging individual cables.

My desktop computer came with only one audio socket, so I installed one of these to give me a full range of sockets. It was a bit reluctant at first to work with W11, but it worked after I had spoken firmly to it!

Buy a Y-cable, and wire up your own switch.

Examine the gender of the items carefully, otherwise you'll need a male-to-male short black stereo cable for each interface.

You can buy solder-tail audio connectors, both male and female.

On a DPDT switch, you would feed source audio to the center two pins ("Left" and "Right"), and the NO (Normally Open) and NC (Normally Closed) pins on either end, are the takeoff points for the cables to the two speaker systems and their line level stereo input.

Computer-L Signal ground is common to all items | | Amp#1-L <----X X X----> Amp#2-L

Amp#1-L <----X X X----> Amp#2-R | | Computer-R

The two switch positions do this. Connect one side. Or, the other side.

XoooX X versus X XoooX

XoooX X X XoooX

The computer is safety grounded. The audio amplifiers should be floating, so that the signal ground can be sent to them without causing hum loops.

# Soldertail females if you need them. Good male choice, harder to find.

There are potentially other ways of doing the wiring. You can put a six pin switch on each subtending cable. The switch can select the computer signal, or the switch can ground L and R so hum is not picked up. If there are long cable runs, you may need to do something like this. Buy enough switches so you can entertain either choice. If a scheme is going to cause a problem, you can test by just using the male-with-tail, plug it in and see if it hums. It it happens to be quiet, you can use the plan at the top.

Switch for Amp1 Switch for Amp2 Two of the two position rockers.

Send ground or Send ground or Send signal Send signal

When soldering these items, the plastic cannot take a lot of heat. You can attempt to reflow-solder them. Apply solder to the item first. Then bend the bare wire in a V, make sure it fits the hole without binding, tin it, then when you heat the items when in contact with one another, they can flow a little faster, before the plastic melts. They don't design these things for a good time, using high temperature materials. While you can buy low-temperature solder, I don't recommend it (due to the durability of the material). There are at least a hundred different kinds of solder... if you are a rich individual. I use a fairly thin tin-lead (SN63PB37 0.015) which is close to angel hair. I don't do much soldering these days.

Paul

What would be the downside of leaving both cables plugged in?

Using a Windows dialog, you may be able to switch from "RealTek Speakers" to "RealTek Headphones", so the two cables can be left plugged in, and the switching can be electronic at the source (computer) end. I don't have the front panel hooked up, so my picture is only approximate. There is at least one signal on the header for the front panel audio, which senses whether the cable assembly for it is in place. Then I would have an extra option in my dialog for it. Since my computer is a home brew machine, there are wires all over the place, and the last thing I need is a duff front panel hanging down from the mess :-)

Paul

The downside is that on most occasions I need to have only one of the two sets of speakers active and the other muted. I don't believe that's possible, is it? Also, don't most front-panel audio jacks, being intended for headphones, have an automatic LS cut-off switch?

Thanks for that, but I really want the simplicity and convenience of a simple manual switch.

Thanks so much for your extremely full reply and advice. I have done this kind of thing in the past (and thoroughly enjoyed it), but while I realise that this is expressly a DIY group, I'm afraid that these days I prefer a ready-made solution.

Thanks for the link: it seems like an ideal piece of kit for the audio-socket-deprived PC (and its owner).

Something like this?

Let's start with the basic "Y".

________ / ________/ \ \________

If you put a switch in each branch (keeping neck of Y short), then the switch can switch between Ground in one position, or the switch can pass signal.

Such a setup allows none, one, or two speaker systems to be running, as a function of the upper-arm-switch and the separate lower-arm-switch.

If you use the same kind of six-contact switch right at the joint in the neck, the switch can flick to one side (enabling speaker-set#1) and the other side (enabling speaker-set#2). This means the switch is only 1/2/1/2/1/2... and has no Ground position or All-Off or All-On positions.

If you buy a switch with six contacts on the bottom, and three positions, that's better for making the 1/2/1/2 type of thing. If the switch has six contacts on the bottom and two positions, then a switch in each arm gives the control needed.

But I still feel, that a pack with two of the three position switches, and at least three male cables, can make a basic control. You may still need male-female 15 foot cables as an "extension cable" to reach another room. I keep an extension cable here, male-female, plus a gender changer cable male-male when the gender with my audio cable setup is not correct. The gender changer cable is only around a foot long.

For example, to go from green female PC#1 connector to pink female PC#2 audio input connector (record one PC via another PC), takes the short male-male cable plus the 15 foot male-female cable, for a total reach of sixteen feet.

That's just to give some feeling for the odds n' sods you collect for computer audio in a room.

This is for a switch-per-arm for control. Left position of switch is signals pass to the right of the diagram. The right position of the switch causes Tip and Ring to be grounded (sleeve level). +------------------- Tip Speakers#1 | | +----------------- Ring Speakers#1 | | Male ------------- tip ----------- X X | X---+----------- Sleeve speakers#1 Computer-Out | | Green ------------ ring ----------- X X-+ X---+ | ------------------------sleeve -----------------------+

Versus the one switch, with two choices which are exclusive of one another.

Computer-L Signal ground is common to all items (sleeve joined on all three cables) | | Amp#1-L <----X X X----> Amp#2-L

Amp#1-R <----X X X----> Amp#2-R | | Computer-R

A kit of connectors with pre-attached cables (and solder ends) is one component. The kit has both male-with-wire and female-with-wire item, and you can select a gender according to the distance the speakers are from the bodge. You would use female connectors on the arms... if planning to add 15 foot male-female extension cables.

A pack of six contact, three position switches, you can build either diagram.

The three position switch is so the rocker can have 1 - None - 2 as its choices, But it has the risk it might hum (as it isn't exerting as much control over the signals).

The switch per branch, grounds the amplifier inputs and reduces the risk of hum, when an amp is "de-selected".

The thing is, audio equipment is always overpriced. To have even a little mixer or patch box, somebody is going to charge you a hundred plus for that. Whereas a little soldering and a few bits and pieces, you can do it for half that or even less.

If the rocker switch has screw-holes on the ends of it, those can be used to fasten the switch to a piece of board. Always consider the mechanical details, as you want a neat little job. You can fish the wires through holes in the board, to take some of the strain off the solder joints. As an example, when I build a lamp here, I do a "ninety degree hole for the lead". Drill two holes that meet, pull through with some wire or cable (like a used bicycle brake cable) so you can get "round the bend" and pull the cable through.

Paul

You will be sorely disappointed in the choices of finished goods.

I didn't do this for fun. It wasn't the mandate of this being a DIY group.

It's because the Chinese suck at thinking a thing through.

If they did make something, the price will be too high, or the materials they select will be poor.

To give an example, I bought a "video selector" box for the room. The buttons they selected were clunky as hell, loose fitting and janky. I was not happy with my purchase, and it never got used. I don't think there was even a means to fasten it to my AV rack.

If I thought good finished goods were available, I would immediately have picked one out. But any items you might see, there are wires all over the place, and they are really not an advantage to the purchaser.

To give an example of another Chinese wonder-box, I bought what I thought was a video capture cable. It was supposed to have passthru. Except, the output is 4K and only drives a 4K monitor. So rather than being agnostic about what it does, it fiddles with the passthru signal and changes the resolution. This makes the box a damn nuisance, and guess what. It sits in the junk room.

I can count on HDMI to VGA and DP to VGA adapters to work. Those are generally flawless. But a number of other application spaces in electronics, the finished goods are just awful. Then we get out our soldering irons...

Paul

OMG. A bridged CM8738!!!

"Support for Windows 7/for Vista/XP 32/64bit PC computer with PCIExpress slot."

Is CMedia still in business ?

Paul

That looks pretty good. It will depend on how janky the switches are, as to whether it is a keeper.

That's a line-level switcher, as indicated by headphones being plugged to the box. 1 volt signal from PC, 32 ohm headphone drive capability.

It also indicates it is bidirectional.

Makes you wonder how that "volume knob" works.

Paul

I'm not trying to be a smart-arse, Bert. I'm just trying to get enough detail from you in order to offer/suggest a worthwhile solution.

Also, don't most front-panel audio jacks, being

Not with my AC97 desktops. They simultaneously pump audio out on both the front Headphone jack and the rear Line Out jack.

And I wasn't suggesting that you were. If you gained that impression, my apologies.

Interesting about the front-panel auto audio shut-off or lack of it.

Thanks.