<p>Hm, I haven't encountered this problem yet, but I would check the usual suspects, bad solder joints, wrong values of caps or resistors in the 4th oscillator's 556 section of the schematic etc. Could you explain a bit more what you mean? When all the divider knobs (green) are turned entirely clockwise, the fourth LED lags considerably? Is the tremolo matching up with the LED?
</p>
