[sdiy] sync circuit woes

[Dan Snazelle]

working with the sync circuit that is HERE (on 2 pages)


http://www.elby-designs.com/asm-2/vco/vco1-summer-asm2-cct.pdf
http://www.elby-designs.com/asm-2/vco/vco1-cco-asm2-cct.pdf


I am getting the sync signal coming IN to the input. i am getting that into pin 3 of the Tl081/71

the resistors are getting gnd and -15v

i need to figure out how to test from that point on. (pin 6 and on)

since the output of that first opamp is a comparator, i cant check for sound. can i check for something on a scope?
or a DVM?

I had to fix the VCO to work with a 10pf timing cap instead of an 18pf..it wouldnt work without that change....could that make a difference? maybe i need to change some values?

are there any common issues with sync circuits i could be on the lookout for?


i will start checking for cold solder joints.

i really appreciate it


THANKS!!!