EDN catches up: multiphase sine waves from CMOS

[R.G.]

http://www.edn.com/article/CA6321527.html

[Processaurus]

Great link, its a good supplement to the GEO article about shift register LFOs, because it gives resistor values for summing the outputs to make an accurate (1%) sine wave. 

[Nasse]

Just one phase might be nice sine for bass synth

[Tim Escobedo]

Synth DIYer Harry Bissell came up with a nifty three phase VCO based on a earlier design. Not CMOS, however Bissell knows his stuff around electronic musical applications, so I'd expect some of the bugs to be worked out already. Plus he's a pretty easy person to contact should any questions arise.

[R.G.]

One of the nice things about digital synthesis with shift registers is that if you can stand for smoothing off the jaggies on the waveforms is that you can produce multiphase things that are not just sine waves, but triangles, hyper triangles, squares, etc. by changing the resistor weightings. You can change the phase difference by where in the shift ring you tap the phase summation networks.

I like them.

But that's just me.