If you purchased a Leeds Fuzz kit sometime in the last week of June 2011 - the second week of July 2011, there's a good chance your kit came with a defective stereo jack. If your pedal does not work in the on or bypass position; and the LED is dim when the pedal is on; AND your stereo IN jack looks like the inverted jack in the picture below, then this is your problem.
The manufactuer mixed up the TIP and RING. This would cause your guitar signal to be grounded whether your pedal was in bypass or on.
The fix is simple. Since the jack still functions perfectly, just swap the ring and tip wires.
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*patience is a virtue*
Please do not PM me. email is prefered.
keith@buildyourownclone.com