[sdiy] Keyboard Circuit - Seperate Keyboard and Gate buses?

[Harry Bissell Jr]

The unobvious is that the keyboard bus closes first and opens
  last...
  
  so the voltage is applied to the sample/hold input before the gate...
  and the gate goes away before the voltage is removed
  
  H^) harry

Chris Manders <wight446 at yahoo.com> wrote:  Hi folks

I am planning on building a simple keyboard circuit
for my Synth.

Looking at some synth schematics, I notice that a
large amount of them make use of two seperate bus bars
- One for the CV (using a resistor ladder) and one for
the gate. Indeed the (later?) ARP Odyssey used three -
One further to generate an additional trigger pulse.

For the ones that use two, why should they choose
this? Surely (and I what I have in mind) is that if
any voltage is present on the CV input line as a key
touches the resistor ladder, then that would be
sufficient to generate the 'gate'? Surely just one bus
would suffice?

I feel I am missing something obvious (story of my
life, really).   :-)

Chris


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