multiple SID outputs into 1? I know it's possible without a mixer, but...

[cyutaeha]

    ...don't really know how it would be done. I think it's great that the four different SID chips that I use can be used as four separate channels, however I don't have a mixer at the moment. Therefore, for the meantime, limiting me to only one SID at a time. I noticed there are two audio IN OUTs on the SID PCB so...I'm thinking that in addition to the four OUT jacks that I could combine the other OUT portions of the four PCBs into one OUT jack. If possible, how would I go about doing this?

    I'm still fairly new to electronics. I'd be grateful to anyone who could help out.

          Thanks everyone

[nILS]

You basically have 2 fairly easy choices:

1) Passive Mixer

2) Active Mixer

Both are described really well here: http://www.nirvis.com/mixers.htm

[cyutaeha]

oh sweet! God it's so simple, thanks!

[cyutaeha]

ok...so if i were to use this circuit for making a mixer and, say, wanted to throw in some volume pots for each input, what would be used for ground??

[cyutaeha]

So i'm thinking maybe this would be a suitable way to do the pots. I know the best to find out would be just to try it, but I'm wondering if anyone (everyone here knows more about this stuff than I do) could tell me if this even makes any sense.

[seppoman]

No that doesn't make much sense :)

A pot usually has the source signal at one end and ground at the other. the middle connector is the output. your idea would mean: when the pot is full left, you just override the resistor and connect the amp input to ground -> silence. when full right, you'd still not reach max volume because the pot also acts as a "normal resistor", i.e. pulls towards ground against the signal more or less depending on the pot value. So in theory, and as long it's only one channel, this would actually work to influence the volume. but with more than one of these channels, the output would be silenced as soon as any of the pots is turned hard left.

A nice little mixer is e.g. this one:

http://www.musicfromouterspace.com/analogsynth/monomixerpage.html

you can omit the headphone amp portion on the lower right, and the capacitors at the inputs are not absolutely essential.

S

[cyutaeha]

What's up with this, then. The mixer you gave shows the pots being used like you said, but what's up with this stuff.

[seppoman]

well that image doesn't contradict my post :) What I described is the example labeled "Volume Control" (which is exactly what we want to do with it, right?). The "Variable Resistor" usage does exist, but is not suited for your purpose - you can't completely mute an input by that construction and in any case there wouldn't be ground connected to the pot.

S

[syamajala]

Here are some pages I have on active mixers

http://sound.westhost.com/project30.htm

http://www.electronics-lab.com/projects/audio/025/

I plan on designing/building my own mixer based on the esp stuff this summer.