Okay so I've got everything together and followed the biasing directions and I'm getting nothing. Only the Volume control is doing anything at all. I tried several combinations of even extreme trimmer settings and am getting nothing. This is the MN3207 version.
Quite disappointing, as me and my girl of nearly four years also split up yesterday. I need this to cheer me up!
any suggestions would be greatly appreciated.
Sorry to hear that :(
What clock are you using with the MN3207?
Thanks Brian. It'll be alright, one way or the other. :-\
Clock? Uhhh you mean the trimmer or IC?
I'm pretty sure I didn't sub anything at all. Could IC orientation cause this? I wish I had it in front of me!
its one of the ic chips
cd4013
or similar
this'n... a cheapie from Tayda
http://www.taydaelectronics.com/servlet/the-521/CD4013-4013-IC-CMOS/Detail
Voltages?
Quote from: TheCobbenator on December 10, 2011, 06:08:06 PM
Thanks Brian. It'll be alright, one way or the other. :-\
Clock? Uhhh you mean the trimmer or IC?
I'm pretty sure I didn't sub anything at all. Could IC orientation cause this? I wish I had it in front of me!
Yeah...ICs only go one way :)
First I would start checking over the resistor values to make sure they are all correct. One off value can cause issues, and I can't tell you how many times I've seen people swear their values are all right, only to find out later they had a single incorrect resistor (hey I do it too!). At the same time, taking some voltage readings on the pins of the MN3207 will also help. And make sure you have the jumpers set properly for the IC (info is in the build docs).
Next up might be an audio probe.
Sweet. Thanks guys. I'm looking forward to getting a chance to dig into this again.
Yeah, the IC question was stupid. I just put an IC in backwards one time on purpose to make sure that wasn't my problem on a perf build that was a bust.
I'm positive I oriented the jumpers under the MN3207 correctly, but I will check resistor values.
Are there certain positions I need to put the pots and trimmers in to get the necessary voltage readings?
Then, where do I put my DMM leads to get voltage? just negative to ground and positive to whatever pin I'm testing?
I'll also post a pic of my D4 junction, I'm not 100% sure I did that right either.
...to be continued
Any updates?
Your description of DMm use is fine. Connect power and the any ground connect your black probe the use the red probe to measure each ic pin and transistor lead and post them up.
Area you sure you set the knobs as per the BOM for basing? And tried the full range of the bias trim slowly? Depending on the trim I guess and the bad there may only be a small window where the chip will bias and produce flange correctly.
Hope that helps. I just validated a mn3007 build but will try to help you out if I can..
Hi there guys,
I'm having the same problem with my build. only the volume works.
So I whipped out my audio probe and started mucking around.
Odd things is I grounded pin 4 of the mn3007 just for a second and the pedal came to live. So I though maybe it was a one off, biased it and everything was fine. Worked great until I unplugged the power like what I'd normally do. Next day, same problem. So now a little wiser, I tried grounding pin 4 again and it worked. Removing the ground source didn't stop it from working. It just kept on and on. Unplugging the power temporarily didn't stop it from working. It's the long power downs that trips it. Then I have to quickly ground pin 4 again.
Anyone knows why this is happening?
Marc
Sounds similar to this problem here. http://www.madbeanpedals.com/forum/index.php?topic=3637.0
Did you jumper C5 ?
you know what marmaliser,
i'm an idiot.
Thank you for pointing that out.