A schmitt trigger is not the way to go, Its merely a comparator of a sort which takes a noisy input and cleans it up.

 

What you want is to create a cloack signal with the 555 timer, then use a POT for the resistance. This gives you a variable speed clock signal. You then feed this new clock signal into the 707 and I think you remove the origional clock, you can do this by cutting the trace and then you can feed both clocks to a DPDT switch. You will have the origional clock signal when toggled one direction and the new clock in the other direction. Then the POT can be adjusted to speed up and slow down the pitch.

 

I hope this helps point you in the right direction. I dont know anything about the 707 I dont have one yet, Im looking to get one, so thats all I know.

 

Good Luck,

Jesse

 

----- Original Message ----
From: cosmosuave <race_slick@...>
To: tr-707@yahoogroups.com
Sent: Tuesday, January 16, 2007 5:23:23 PM
Subject: [tr-707] New to Board Req 555 Oscillator Help..

JUst like to say hi and wa referred here from gzifcak from
livepa.org.. . I have had my TR707 for 8 yrs and never thought it could
be modded for pitch and decay guess I was wrong... I do have some
electronics expreience having built a Theremin and a Sound Lab Mini-
Synth...

http://www.musicfro mouterspace. com/analogsynth/ SOUNDLABMINISYNT H/soundla
b.html

I'm a little confused regarding the 555 osc/timer... I came across this
site but I have no idea which timer to build Should I build the
schmitt trigger timer or better timer..

Below is the link for these two..Scroll to the bottom..

http://www.uoguelph .ca/~antoon/ gadgets/555/ 555.html

Thanks... I'm proficient at building but lack in the theory...