Yesterday I was injecting in pin 3, but the resutal is identical when using the other pins, an ugly sound. I used to inject signal, first a 40106 oscillator, to see that it was not what I wanted to test my hewlett packard generator, the result itself. I remember the circuit of the tr 909, which is almost identical, it has a 4011 + RC and an envelope that is generated. The other instruments of tr 707 during a wide range of bend sounded good, but Ride is different. I would like to hear a Circuit bender demo, the one that is hosted on the page does not differ much, but for some reason they decided to use the same clock for both instruments.