BillFitzmaurice.info

If I build a single Jack as a pool/party speaker driven by a Lepai stereo amp, is there ae easy way to convert the 1/8" stereo output from an MP3 player to mono? I don't want only the right or left channel sound going to the amp, but rather a full mono.

This is very interesting, and on topic:
http://www.rane.com/note109.html

like this?

http://www.monoprice.com/products/produ ... 1&format=2

Jon Barnhardt wrote:like this?

http://www.monoprice.com/products/produ ... 1&format=2

33 cents? I don't have that kind of money just laying around! Actually I was aware of these adapter plugs but do not know if it actually converts the left and right signals into a mono sound or if itjust physically fits the 2 plugs.

Read the Rane note linked above. That's essentially a Y-cord, when used to mix stereo channels to mono. It will physically work, but it's not a good idea at all.

SirNickity wrote:Read the Rane note linked above. That's essentially a Y-cord, when used to mix stereo channels to mono. It will physically work, but it's not a good idea at all.

Tell that to the thousands of us who have been doing it successfully for years. I've bought cables like that and I've built 'em. They work fine.

If you want to buy an expensive box to do the job - fine, but it's certainly not necessary for running any device that gonna' be on the other end of a mini-plug. We're talking MP3 here, right? Let's not get too persnickety, sirNickity!

I have run into a situation where an ipod didn't like having it's l&r outputs wyed together. The resulting signal sounded very bizarre. The best way is the simple, cheap resistor network shown in the rane note. (stereo to mono summing box) RDL also makes a nice little device for that -
http://www.rdlnet.com/product.php?page=349
A cheap little mixer could also be used

The rane summing method is so easy. In the picture above I salvaged the resitors from an old electronic device. You can look up the values here. I had to double up on resistors in series on the + leads to get a value close to the recommended one. The resistor in the middle shorts to ground. Inputs on the right, yellow is the + out, white is the - out. The group of wires in the middle is an isolator (ground loop preventer) and can be ignored.

Thanks for the info guys. I may just try the adapter plug and see how it goes. The electronic components for the box are only a couple bucks, so I may try that eventually.

Here is a schematic about two-thirds the way down..... http://www.colomar.com/Shavano/patchbox.html

Jon Barnhardt wrote:like this?

http://www.monoprice.com/products/produ ... 1&format=2

This is backwards. He needs to convert stereo to mono.

http://www.radioshack.com/product/index ... Id=2062469

Your solution would use the left channel (tip) and ground the right channel (ring). While you end up with mono, it's not summed mono, it's just half of stereo.

Bruce -- fair enough, it can and does work fine in many cases without fail.

Fo what it's worth, I've never seen an output stage permanently harmed by combining outputs, but that's partly because I don't do it. I've heard it's possible. I'm not an authority on that subject.

As Greg said, sometimes it causes weird side effects -- which I *have* seen back when I was younger and trying to plug two mono game consoles into the same TV audio input.

So, in this case, I feel like it's the responsible thing to do to say: You shouldn't do this, but you can, and if you do, be aware in rare cases it could get ugly. Then, it's your call.