Dead Zombie Chorus

[Connoisseur of Distortion]

just brought myself to work on it some more... and now i think i ruined it

when i powered it up, no sound came through. i looked along the board, trying to see what the problem might be... then i touched the CD4046 and burned myself. any ideas what could push it to get so hot?

[Connoisseur of Distortion]

i cleaned up a few traces that looked sketchy, and i discovered that the hiss from my amp changes in pitch and "tone" as i twist the pots. however, the CD4046 is still hot to the touch when i power it up. is this maybe a symptom of the static kill that this type of device is so vulnerable to?

[MartyMart]

Sounds to me like there is 9v going where it should'nt ! that will usually get an ic very hot.
Do you have a schematic for it, you could post ?

Marty.

[lightningfingers]

Schematic

[Connoisseur of Distortion]

Thank you for the advice!

I looked at a pinout of the CD4046, and it says that 14 is the Signal In. Should we be running 9v into the input? if not, what should i be hooking into it?

[Connoisseur of Distortion]

discovery!

the layout and schematic of the chorus show no connection from 14 to 16, but the toner transfer DOES  :?

anyone know what feeding 9v into the input is? maybe "hot"?

BTW, i am using the pdf file at GEO

http://geofex.com/

sorry, but i can't send the url of the actual pdf...  

Thanks again![/i]

[Connoisseur of Distortion]

i broke the connection between 14 and 16, and fired it up again. It still is running dangerously hot, and i'm starting to think i might have melted the innards together, or something.

I have a backup... but i don't want to use it until i am certain that the issue has been cleaned up.

any other stuff i should look into?

[MartyMart]

I just took a look at the "Ultra Flanger" at your GEO link, it's also by John Hollis, definately has +9v to pins 16 and 14 on that 4046, there's a 27k resistor infront of those connections also.
Your problem is possibly somewhere else, I can't follow that hand drawn schem too easily, and dont know the 4046 well at all !!
Could be "burnt up" allready, if its running too hot to touch.

Best of luck,
Marty.

[lightningfingers]

pins 14 and 16 should go straight to +9V, I take it you mean y0ou are getting +9V from the lfo output, this is a bad thing and will certainly fry your 4046 to a crisp. pull the dead one out, and look for mistakes in the lfo, dont put the new 4046 in until you are SURE it works. DONT GIVE UP   it sounds great!

[Connoisseur of Distortion]

U3 (dual opmamp) is the lfo, isn't it? i used a TLO82, instead of the recommended 72 or 62... Maybe it's the problem?

[Connoisseur of Distortion]

i think i may have found the problem, but i am far too embarassed to post it. i will have to check, them tell everyone if it works...

[Connoisseur of Distortion]

update: it no longer heats up when it's on. however, it is still buzzing. when turning pots, i can change the pitch of the buzzing and the volume of the buzzing. new experts, please  :lol:

PS: if you guys help me get it working, i'll tell you my grueling mistake  :wink:

[Connoisseur of Distortion]

i got it working!

thank you for bringing up the 9v issue... because of it, i noted that my CD4046 was upside down  :shock:

then, i did one of my favorite tricks and ran my signal into the ground. when i fixed that, a hyper-wavery whine shot from my amp when i activated it.

This thing's pretty cool. The LFO is really moving, though, and that is kinda bothersome... i'll bet if i put the right pots in, it'll smooth out.

Thank you, everyone!

[lightningfingers]

congratulations! do you hear the ticking that so many people have complained about? 'cause theres a great little fix on Mark Hammer's page for that.

[MartyMart]

OOP's  :oops:
Glad you got it working !
Dont worry, we've all done that at least once, I doubt that you'll do it again !!

Marty.

[Connoisseur of Distortion]

i hear the ticking, but my setup has a neat little noise gate which seems to do fine... i'll look into the idea, though...

I thought i'd be pretty exclusive with the upside down trick  :shock:
now i have to think of some other way to totally ruin it...[/img]