Janglebox Vero Issue

Forum dedicated to helping people debug and troubleshoot non-functional pedals or builds. Please use an clear and informative title, indicating circuit and basic problem. Don't forget to mark the issue as fixed if this is the case.
Post Reply
User avatar
kayrosso
Information
Posts: 1
Joined: 12 May 2023, 20:25

Post by kayrosso »

Built out a janglebox using the lm13700 layout and not getting expected behavior.

Getting a mis-biased type sound, with sound only kicking in with louder notes and decay sputtering out then abrupt silence.

Video here:


Pictures of top and bottom of board:

https://pasteboard.co/cJtpy3dKxLHk.jpg

https://pasteboard.co/gWTxF3OqTbZw.jpg


Pins 3 and 4 are giving me an expected voltage reading of about 2.92v with a .02v max differential between them. Pin 1 is 1.31v with attack at max and 1.20v at min.


Issue seems to stem from pin 5. Getting a voltage reading of .68v. My understanding is that the 220k resistor should be measuring 2.78v across but end at VB is 2.78v while end going to pin 5 jumper is at .68v.


Any ideas what might be the issue here?
Attachments
2CABD30E-7D02-4C44-8A60-449B43627BD1.png

User avatar
Lani
Solder Soldier
Information
Posts: 192
Joined: 22 May 2017, 11:57
my favorite amplifier: Bassman 5f6a
Completed builds: .....ummmm yeah. Too many to list.....
Location: Ithaca, New York
Has thanked: 133 times
Been thanked: 93 times

Post by Lani »

I would run a knife down the board on the solder side in between the tracks. Would also make sure your getting no continuity where your breaks are. Soldering looks good so my guess is there is a hairline short in one of those two areas (in between tracks or breaks in tracks)

User avatar
mauman
Resistor Ronker
Information
Posts: 415
Joined: 17 Jun 2017, 20:01
Location: Texas, US
Has thanked: 420 times
Been thanked: 181 times

Post by mauman »

+1 to Lani's ideas, make sure all your cuts are truly cut, including the one in the green circle by pin 5. Also knife-blade the tracks, including the suspicious locations in the orange circles (but there are others.)
Jangle.jpg

Post Reply