Bump.

Speak and Read added!

Also not wanting to hijack this most excellent sale thread, but I thought I'd mention that the foam-stuff inside the plastic case you used for this mixer may be somewhat conductive, which might cause problems in certain use situations.. That might be worth looking into. You could probably check with a multimeter.

uhhh, anyway everybody buy katsum's stuff kthxbye

Bump.

The schematic I made for my passive mixer.

No offense taken man, I know my soldering skills need improving, at least aesthetically I used too much solder and it looks pretty messy. But I definitely get signal through all channels. Sorry to somewhat derail your sale thread. The picture of yours is really sharp and clean looking; much nicer than mine. People should buy these.
Thanks for all your input on this though, I really appreciate it. I'm making another passive mixer once I buy more jacks, this one using a schematic by TylerBarnes. We'll see how she turns out

If there was an issue, from the photo you took, it might be the solder connections you made from the stereo jack legs to the resistor legs. A few of them look a little sloppy. Not trying to sound like a dick but that is my observation from the photo alone. I don't have your mixer right in front of me.

The only difference between designs is that I'm having all my grounds wired to a ground point on my perforated board. Other than that, visually, it looks like your mixer should be working without any issues.

The solder joints are all good, however I could just try making another following a different schematic.
I actually posted a pic of it in the customized gear thread last week. Anything there look funky to you?
http://chipmusic.org/forums/topic/7345/ … d/page/53/

If you are experiencing a "jump" in sound as you are explaining it, it sounds like there is something wrong in your circuit. It may be the circuit you designed for the mixer, a faulty soldered connection, a ground issue. If you are experiencing the same issues when plugged into your prosound as well as the headphone jack, it is the mixer.

If you use a higher ohm rating resistor, there should be less distortion, but the signal will drop in strength making the output quieter. That is the trade off of choosing resistors for a passive mixer set up.

As long as you use computer speakers or a headphone amplifier (I test the mixers using one) then you should be fine with 1K Ohm resistors and ~4 inputs.

With how you are describing the issue to me, it sounds like something isn't wired either correctly or properly in your mixer. I hope that helps.

-Anthony

You're right, I think there is less of a signal difference with prosounded boys. Mainly where it's problematic for me, is in a song when one gameboy has a silent part and you suddenly hear the bump in volume from the other.
Hypothetically, what would happen if I wired the two 1k resistors from the input to a 2k, right before the output?

Shintarou,

I am trying re-create your scenario and I am not experiencing any balance issues.

The only time I am experiencing anything you are explaining is that if I have multiple inputs plugged in, i.e. if I only have one gameboy plugged in, it is "louder" than if I had two plugged in, but that is a trade-off of utilizing passive mixers.

Were all your solder connections solid and did you test for resistance at the jack and wires after you were done with making your mixer?

***edit***
Shintarou,

The drop in signal is more pronounced when plugging in directly to the headphone jack of a gameboy. There is noticeably less drop in signal when plugged into a prosound jack of a gameboy.

I actually just made one of those a couple weeks ago, just in a different plastic case. Super useful and cheap project. However I found that it gets balance issues when you have only one channel quiet or silent... the other side gets much louder. Could be the size of resistors I used (1k), I don't really know how to fix it.
Does that happen with yours?

Added Altoid Tin Mixers. Will be making a run of 16 of these.

Bump.

500GB HDD added for $40 shipped!