Great question. There are a few things that you have to understand in order to do this. When you connect multiple ugens to the input of another ugen the get summed. So, if connect three sinoscs to the dac they will get summed. If they all have an amplitude of one and the same frequency and phase then they will oscillate between -3 and 3. Makes sense.

Alright, you probably want to scale these things you put them into a gain and then into the dac. Then you set the .gain parameter to .333333 and you will get -1 to 1. Fantastic. You probably already know this. But if you want to do ring modulation you can change the .op parameter of gain to 3, which is multiply, and the inputs will be multiplied against each other. 

You can check the manual for the .op parameters of gain. They are:

– -1 passthrough 

– 0 no processing 

– 1 adds inputs (default) 

– 2 subtracts inputs 

– 3 multiplies inputs 

– 4 divides inputs 

For the example you gave, the solution is to connect two ugens to a gain that has the .op set to 1 (default). You add the DC bias by using the step object and setting it to k. 

ChucK has all sorts of effects you can use to put between your oscillator and the dac. You can also start doing different modulation techniques by exploiting the .op feature of gain. 

I hope this helps. 

--art