There is also a 100n cap between pins 1 and 3 of the op-amp, apparently to
speed up the transition. Try removing it. It isn't on the schematics.
Me thinks it's time this went to version 2.
Ken
appear to be on this version, only other difference I see is at the reset
input pad there is a diode going to +15V....
Ken Stone sasami@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
speed up the transition. Try removing it. It isn't on the schematics.
Me thinks it's time this went to version 2.
Ken
>Alright I figured out my Hold problem, defective toggle (my first one haha)...with a 330K like you suggested and nothing....
>
>As for the Reset, no luck.... Parts are correct, I tried replaced the 100K
>a diode, 100k res, 100n cap marked *not present on earlier PCB. It does not
>This is a V1.4 board, on the schem (earlier version) after the 15K there is
appear to be on this version, only other difference I see is at the reset
input pad there is a diode going to +15V....
>pad on the pcb....
>Also I am not using the Disable Jack and have installed the diode afer its
>_______________________________________________________________________
>hmmmmm
>
>
> ----- Original Message -----
> From: sasami@...
> To: cgs_synth@yahoogroups.com
> Sent: Friday, July 27, 2007 10:21 PM
> Subject: Re: [cgs_synth] Debugging Gate Sequencer
>
>
> 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/>
>
>
>
>
>
>[Non-text portions of this message have been removed]
>
>
>
>The CGS Modular Synth home page: http://www.cgs.synth.net/
>
>Yahoo! Groups Links
>
>
>
>
Ken Stone sasami@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>