Pulse Divider / Boolean Logic / XOR-XNOR troubleshooting

[eyehue]

Hi folks!

Sorry to bug you, but I have a problem...

A friend and I made a frac plate to incorporate the CGS Pulse Divider / Boolean Logic / XOR-XNOR / and DC Mixer.

I seem to be able to get everything to work except the Pulse Divider doesn't appear to do anything. I am using the clock out from my Blacet Binary Zone.

Also, while the XOR-XNOR appears to work, the two LEDs for it are always lit until I use the function, then seem to blink appropriately. Is that normal? The AND and OR LEDs only light up when the functions are in use.

I've been over the board a bunch and see no glaring errors. Can anyone give me an idea of where to start poking around to find the issue?

Thanks in advance for any help.

[eyehue]

looks like i got the wrong chips in there

any insight on the XOR-XNOR?

[otherunicorn]

The XOR/XNOR issue could be due to one of the following:
1) an offset in the op-amp due to manufacturing (no big deal)
2) a bad connection the op-amp's negative power rail
3) another contsruction error such as a dry joint on the input stage.

[eyehue]

i've tried all these suggestions to no avail, i feel the pcb has been injured somewhere. i started the circuit from scratch only to find the capacitors aren't in the schematic. anyone have the complete XOR-XNOR schematic?

[andrewF]

The capacitors are for decoupling the power supply. I doubt they have anything to do with your problem.
Assuming the PCB hasn't been damaged, one of Ken's suggestions will sort you out. .
do you have a spare LM358 to try?

[eyehue]

i appreciate the help, Ken and Andrew!

i was told by the guy who gave me the pcb that it may be an early untested run. i was asking about the caps so i could build the circuit from scratch without a pcb. i thought i figured out the decoupling placement of the three caps. i have now built the circuit on perf board and i've tried 5 different opamps, all with the same result. i'm also not sure the original was ever actually working correctly. i've built over 30 modules and have never had these types of problems before. somewhere i am screwing it up. having wasted two days on what should be the simplest circuit of my entire modular, i'll probably give up on this one at this point. hopefully when i get the proper ICs the pulse divider will work.

[otherunicorn]

The early run was never officially released. I think I gave a few away. The LEDs are connected to -VE instead of 0V. That will be your problem.

[eyehue]

THANKS KEN!!!!

somehow i made exactly the same mistake in reconstructing the circuit. i'll have it fixed today and once the whole combo module is finished i will post a pic here this week. keep up the great work at CGS!!!!!

[eyehue]

Thanks Ken and Andrew for helping me out! It's all done and functioning now. Here's the pic:

[otherunicorn]

Cool Panels are where I usually get stuck!

[ark]

[otherunicorn]

[Cat-A-Tonic]

That is an awesome panel design!
I've got the Metalbox version and am quite happy with it.
It has a 4 way mult....
but your addition of the mixer, WOW great functional density.

Sometimes I use the Pulse Divider section to get subharmonics, but it really excels as a timing accessory for a sequencer/clock.

The Logic sections are neat for changing & combining tonalities and CV, but I have a feeling I am missing something about their usage. It seems that the signals have to be of similar levels for the Logic function to be an interesting merger of the 2. Otherwise the one just dominates.

Does anyone have any tips about using Logic in a patch?

[eyehue]

thanks!

we were inspired by the metalbox panel design for sure, but felt that multiples are best reserved for frac ears in our systems. i had the pcb for the mixer, and it was a perfect fit. my modular was really in need of some mixing capabilities, too, to free up space on my mackie.