TC Stereo Chorus/Flanger voltages

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.
Locked
User avatar
jdub
Information
Posts: 10
Joined: 11 Dec 2008, 23:46
Has thanked: 15 times
Been thanked: 12 times

Post by jdub »

Hi, I'm working on a TC Stereo Chorus as detailed in this post: viewtopic.php?f=1&t=18002. Unfortunately, after making and populating boards, I've hit a brick wall (getting only buzz), and in order to troubleshoot need the IC voltages from a functioning unit. Would anyone who owns one be willing to take some measurements and assist? Many thanks!

User avatar
jdub
Information
Posts: 10
Joined: 11 Dec 2008, 23:46
Has thanked: 15 times
Been thanked: 12 times

Post by jdub »

Apologies, meant to post this in the "Requests" forum but cannot edit or delete. :oops:

User avatar
Fender3D
Cap Cooler
Information
Posts: 573
Joined: 08 Aug 2009, 02:40
Location: Helltaly
Has thanked: 121 times
Been thanked: 153 times

Post by Fender3D »

jdub wrote:...in order to troubleshoot need the IC voltages from a functioning unit.
I think you'll need more than just voltages...
this is not a project to do "by numbers". you'll need to know how THESE chips work, or need to work, since there are few regulation points and bias voltages usually come from the previous chip... see BBD bias.

Voltages are more or less as usual: 1/2Vcc @ op amps pins, as per datasheets on the other chips. Variable voltages @ LFO and logic (+Vcc or GND) @ 4007 and 4016

User avatar
jdub
Information
Posts: 10
Joined: 11 Dec 2008, 23:46
Has thanked: 15 times
Been thanked: 12 times

Post by jdub »

Fully agree! But you gotta start somewhere...thanks for the reply.

User avatar
Scruffie
Opamp Operator
Information
Posts: 1739
Joined: 13 Mar 2009, 17:59
Location: UK
Has thanked: 28 times
Been thanked: 170 times

Post by Scruffie »

As usual I do agree with Fender3D but, if you post your voltages, it might be possible to spot something.

User avatar
jdub
Information
Posts: 10
Joined: 11 Dec 2008, 23:46
Has thanked: 15 times
Been thanked: 12 times

Post by jdub »

After audio-probing, it turns out the problem was a ground issue with the enclosed output jack, and I've got success! :horsey: Still need to calibrate and tweak, but once I do I'll post details. Might be a little while though, I'm only working on it when I have spare time. Also want to get the OK from Bajaman to post the edited PCB transfers. Thanks for the replies!

User avatar
bajaman
Old Solderhand
Information
Posts: 4549
Joined: 26 Jun 2007, 21:18
Location: New Brighton, Christchurch, NZ
Has thanked: 595 times
Been thanked: 2058 times

Post by bajaman »

ok by me :wink:
cheers
bajaman
be kind to all animals - especially human beings

Locked