Sold one of my internal organs recently (hah) so I could procure some LM565CN ICs on ebay in hopes of building this up. Looking at DEFx's schematic, and I'm curious what the omitted 7v zener that goes between the 9v and the CLR (that you omitted) is all about? Also the omitted 1m resistor to VRef on pin 3 of the 4558. Not trying to point out errors or anything, just wanting to understand why? Thanks again for all your work, Anders!
Now the OSC switch has all three contacts closed - this is not correct. Pins 1 and 2 must be connected with a 100n capacitor. This capacitor is not connected at all now (from the 7th leg of the LM565, after the 1k resistor).
Built it, no success....checked the schem and finally got it working. The following corrections are needed: -add in series between O-T 9 A 10u cap and a 4k7 resistor, with the positive cap lead at pin 7 of IC1 -add a 1M resistor between L and Q10 -I added a 20k pot between B20 and G20 for frequency sweep as I do not intend to use an exp pedal -trimpot to be adjusted where noise is minimum. With these algood, working. Cheers!
Help me figure it out - when you turn on the OSC toggle switch, there is a constant sound, the pitch of which is controlled by the FREQ knob. Is that how it should be?
Sold one of my internal organs recently (hah) so I could procure some LM565CN ICs on ebay in hopes of building this up. Looking at DEFx's schematic, and I'm curious what the omitted 7v zener that goes between the 9v and the CLR (that you omitted) is all about? Also the omitted 1m resistor to VRef on pin 3 of the 4558. Not trying to point out errors or anything, just wanting to understand why? Thanks again for all your work, Anders!
ReplyDeleteYhe 1m Vref resistor was missing indeed. It is now added.:-)
DeleteThe zener connecting to the LED can be added but I usually omit it, It is only useful if you want the LED to get dim if your battery is getting weak.
Whoa. Did I just peer edit your drawing? Check out the big brain on me!
DeleteOn the 7th leg of 4558, the chain to the ground is lost (10u+4k7). Will it work correctly without this?
ReplyDeleteOuch! And unfortunately there are more mistakes...
ReplyDeleteNow the OSC switch has all three contacts closed - this is not correct. Pins 1 and 2 must be connected with a 100n capacitor. This capacitor is not connected at all now (from the 7th leg of the LM565, after the 1k resistor).
ReplyDeleteBuilt it, no success....checked the schem and finally got it working. The following corrections are needed:
ReplyDelete-add in series between O-T 9 A 10u cap and a 4k7 resistor, with the positive cap lead at pin 7 of IC1
-add a 1M resistor between L and Q10
-I added a 20k pot between B20 and G20 for frequency sweep as I do not intend to use an exp pedal
-trimpot to be adjusted where noise is minimum.
With these algood, working.
Cheers!
Great!
DeleteI'll correct the layout ASAP.
Help me figure it out - when you turn on the OSC toggle switch, there is a constant sound, the pitch of which is controlled by the FREQ knob. Is that how it should be?
ReplyDeletemy working PCB: https://photos.app.goo.gl/yLVpr4rFRy35DM6L6
Delete