Now I've got this going I think it's a really nice little sequencer.
Great feature set, with the triggers and step length control.

...but without a fix it wouldn't run, the input on the op amp where the clock comes in had been left floating by the designer and with a genuine TL072 the clock in stops functioning as charge builds up. Added 3M3 resistor to ground (back of board) and it comes to life. (probably with a cheap "fake" op amp the problem does not manifest, lower input impedance)
Voltage range of out put is 0-10V, so needs to be used with an attenuator. (I added voltage divider on output for 0-5V)
There's no protection against reverse connection, no 100n caps near the op amps for stability...but it works.

It doesn't go far into the audio range, and timing on the CV lags the clock, imperceptably but enough to confuse one of my quantisers (some quantisers have a setting for this reason)

Easy build and the only special component is the rotary switch.


AndyButler
Thanks for the write up on this . The CMOS 4017 has always seen the perfect chip to make a sequencer out of.
Now I want to see some make a compressor circuit using an LM3915 Audio Dot/Bar Display driver
to control multiple OpAmp gain.