best way to mix a few audio signals?

[dentaku]

I built a simple circuit that take a 2V p-p triangle wave from my little DDS function generator (or any audio signal) and turns it into a square wave using a LM358 as a comparator. I have a pot that lets me adjust the pulsewidth by moving the point at which the comparator flips.
This then goes through a divide by three circuit made with a 40hc386 and a 40103.
This gives me three different signals, none of them are AC coupled and some of them are 0-5V.
I also have a 74393 on the same breadboard that lets my divide it by 2/4/8/16 etc.

QUESTION: What's the proper way to mix a bunch of signals like this together. I want to output the mixed signal to an audio amp in the end.
There's lots of different info about building simple mixers online but I was just wondering what the EEVBlog forum members think.

[Synthetase]

You may find this article helpful. It goes through the pros and cons of different techniques.

[sync]

This is the mixer of an Arp Odyssey. Very simple. The inputs are DC coupled. The output to the VCF is AC coupled.

[dentaku]

You may find this article helpful. It goes through the pros and cons of different techniques.

I've found lots of useful from Rod Elliott in the past