Elektor Formant Modular

Hi,

Depending on which circuit you have the modification should be very simple. 
On the original circuit there is a wire bridge on the PCB which is the 
largest to the right of D3. Simply using this junction would allow you to 
input a gate voltage from the front panel. However this would mean that the 
noraml input at the rear of the PCB will need to be removed.

Another option is to use a mono socket with a switch which I found to be the 
comon part you could buy anyway and I use them troughout. Now where to 
connect it is the issue. The circuit would be required to have the original 
Gate path interupted. This can be done by simply removing the previous 
bridge connection (Gate to R5) and then.....

Socket used!
_______  __(Output of socket)
|           |
|           |
------------  __(Internal input)
  |(Ground)

The existing wire connected to switch B should be cut and soldered to the 
output of socket this will allow any of the Gate voltages to flow into the 
switch so AD mode can still be selected. A second wire is required from this 
connection (Output). This will connect to the removed bridge, at the lower 
point that is connected to R5 (The one in line with D3) This is important as 
this is the actual gate input to the circuit.

Now to allow the Internal Gate to connect the Connection B of the PCB should 
be connected to the Internal input pin of the socket. Now normally the old 
gate voltage from the Keyboard will still work as it always has. But when an 
exrternal gate signal is plugged into the socket which will be mounted on 
the front panel the socket acts as a switch and only allows the external 
signal to flow giving an option of having a different gate control.

Hope this is what you were looking for.
Kris Bishop



>From: "markfrancombe" <mark@...>
>Reply-To: ElektorFormant@yahoogroups.com
>To: ElektorFormant@yahoogroups.com
>Subject: [ElektorFormant] ADSR gate In mod
>Date: Sun, 17 Apr 2005 13:33:23 -0000
>
>
>As my Formant was built pretty much as close to the manual as poss,
>the only way of triggering the ADSR's is via the keyboard. Always
>thought it strange that a gate input was not included on the front.
>As I want to get my panel design correct for any mods I may do.. I'd
>like to ask... how hard is it to add a gate in to the circuit? I can
>see where the keyboard attatches (via the weird little module that I
>dont know what it does) is there a suitable place to bring a wire to
>a jack on the front panel, so i can trigger from pulses, lfo's etc??
>
>Cheers MArk...
>
>PS:Despite the expense I decided to go with the Shaeffer method..
>just seemed quick, simple, and high quality. finished the ADSR
>design, looks good. When I have finished and recieved the panels,
>Ill upload the Schaeffer files, so all can use if they wanna go that
>route?
>PPS: Of course if someone has already used Shaeffer and has some
>files, then gimme gimme gimme!! Its a lot of work! Anyone got
>Shaeffer horror stories?.. Anyway now I'm making my usual mistake of
>posting too many Q's in one post. The SUB questions get answered and
>my MAIN query gets lost.. so reminder.. ADSR.. Trig in's?? Anyone?
>Buhler? Anyone?
>
>
>