madbeanpedals::forum

Projects => Tech Help - Projects Page => Topic started by: uber on October 25, 2014, 08:56:27 PM

Title: Low Rider Troubleshooting
Post by: uber on October 25, 2014, 08:56:27 PM
So I populated my Low Rider Build and hooked it up to my test rig to bias the trimpot per the instructions.

I was able to get a single and the down octave effect sounded good, but a bit noisy.   However, when the UOCT1 pot was turned halfway clockwise or higher, the signal was gone completely and adjusting the trimpot seemed to have no effect on this or the sound when I was able to get some with the pot turned below halfway. 

I will get voltages from the 6 ICs and post, but after taking a good look over things I wanted to ask a preliminary Q:

I have had several projects where the ICs are identified without a package type, which I assume is because the different manufacturers have different codes.  However, I was thinking that I may have used the wrong type of IC here, which would cause problems..

I have the following ICs on the board:
IC1 - TL072CP
IC2 - LM324N
IC3 - CD4013BE
IC4 - CD4013BCN
IC5 - TL074CN
IC6 - TL074CN

FYI, I did use the upper octave mod found in the instructions, omitting C12 and substituting a 10n for C10.  There's a pic in case it helps.

Thanks in advance!(http://i.imgur.com/k4a9XXV.jpg)
Title: Re: Low Rider Troubleshooting
Post by: m-Kresol on October 25, 2014, 09:29:19 PM
I think you should have omitted C12 completely without jumpering it.
Title: Re: Low Rider Troubleshooting
Post by: the3secondrule on October 25, 2014, 09:32:23 PM
Quote from: m-Kresol on October 25, 2014, 09:29:19 PM
I think you should have omitted C12 completely without jumpering it.

^^ this - have a look at the schematic. jumpering C12 is shunting the octave up signal to ground
Title: Re: Low Rider Troubleshooting
Post by: uber on October 25, 2014, 10:08:25 PM
Awesome!  That was it... glad I posted the pic.  Thank you both for the quick responses, I really appreciate it.  Now on to troubleshoot the Current Lover...