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Cgs synth

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Re: Debugging Gate Sequencer

2007-07-28 by sasami@hotkey.net.au

First, I suggest that you have a parts installation error around the reset
input. Failing that:-

>My reset jack will reset with a gate of approx 10V, the 5V gate outs of say
my Sequential Swicth will not reset the module.

It should be sensitive to around 2 volts. Try increasing the value of the
100k from pin 3 to earth to 330k.

>In Hold mode it is not working correctly, with a sequence of 8 steps when I
change it to Hold mode it will just loop between 2-8, and as I change
sequence length it will loop between smaller amounts... Every now and than
when I change the sequence length it will work correctly for a second.

behavior wne actually rotating the switch can be eratic.

>I am using a LM358 on the main board, I tried a few TL072cp and I cannot
get the 4017 to clock at all with the TL072.

Try different LM358 or other op-amps. If you can only get TL072, disconnect
its pin 4 and connect it to -VE instead of 0V AND add a diode between pin 7
of the TL072 and pin 14 of the 4017, cutting the track (i.e. put the diode
in series, cathode towards the 4017). Add a 100k from pin 14 of the 4017 to
0 volts.

>I've swapped out the 4017 for another althou all I have on hand is CD4017BE.

Nothing wrong with those 4017.

Ken
_______________________________________________________________________
Ken Stone sasami@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>

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