Colorsound Overdrive pedal troubles

Frequent questions about dead or faulty pedals. Whether you repair, mod or build pedals, debugging is important. Threads about general debugging problems irrespective of the circuit involved...
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Posts: 1
Joined: 02 Feb 2013, 23:54

Post by JohnRhodes »

Hey there! I recently built a Colorsound Overdriver following the ... river.html layout.

1. My problem is that the drive pot only really does anything at the very end of the taper, the sound is non-existant when the drive is low or down, clean in the middle and then all of a sudden is fuzzy. There's no overdrive in the middle, and the volume is very low until the very last portion of the taper. The pot is a 10k linear pot as suggested by the guy on tagboardeffects. I've heard that Colorsound Overdrivers are supposed to be fuzzy at max though. Anyway, something must be wrong.
2.Name of the circuit = Colorsound Overdriver
3.Source of the circuit (URL of schematic or project) = tagboardeffects
4.Any modifications to the circuit? No
5.Any parts substitutions? No
6.Positive ground to negative ground conversion? No
7.Turn your meter on, set it to the 10V or 20V scale. Remove the battery from the battery clip. Probe the battery terminals with the meter leads before putting it in the clip. What is the out of circuit battery voltage? => 7.5v (I measured the battery, is that right?)
Now insert the battery into the clip. If your effect is wired so that a plug must be in the input or output jack to turn the battery power on, insert one end of a cord into that jack. Connect the negative/black meter lead to signal ground by clipping the negative/black lead to the outer sleeve of the input or output jack, whichever does not have a plug in it. With the negative lead on signal ground, measure the following:
Voltage at the circuit board end of the red battery lead = I don't understand where to measure
Voltage at the circuit board end of the black battery lead =I don't understand where to measure

Now, using the original schematic as a reference for which part is which (that is, which transistor is Q1, Q2, etc. and which IC is IC1, IC2, C1, and so on) measure and list the voltage on each pin of every transistor and IC. Just keep the black lead on ground, and touch the pointed end of the red probe to each one in turn. Report the voltages as follows:

C =3v
B =1v
E = 1-1.5v



Here are some pics!

Thanks in advance!

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