From the MAKE Flickr pool

Matt the Modulator shares some key solder points on the SX-150 analog synth PCB, allowing for -

• envelope triggering

• frequency to voltage output
• self oscillating filter
• LFO to filter cuttoff

To see the specific points in question, check out the photo’s notes on Flickr. He also points out that the SX-150 can be easily controlled via the output of a Gakken Mini-Theremin kit -

The gakken theremin can be used to control the SX-150 which has a much better tone and a LFO for that Violin / cello effect. The ext input of the SX-150 is a Frequency to voltage converter and so any synth can be used to control the pitch of the SX-150 but a signal with a high amplitude is needed (about 3v+)

I too have used these in combination and can attest to their awesomeness =]

In the Maker Shed:


SX-150 Analog Synthesizer Kit & Mini-Theremin