freestompboxes.org

The diode of the switching circuit is broken, visible on that shot.
The anode is connected to the JFET gates.
The foot switch switches mechanical between the on-state and off-state.

Is that the same board used in the LocoBox pedals?

theehman wrote:Is that the same board used in the LocoBox pedals?

Yes,it is.

The Schematic was faulty, the IC pin lables were wrong and the capacitor to the level pot is 47nF not 47uf.
Here the corrected schematic.

Schematic is still wrong. there is no cap in parallel to the diodes, this cap is after the 27k-resistor near the tone-pot

And BTW:
the resistors near the tone control are - according to the picture - 27k and not 47k.

tube-exorcist wrote:And BTW:
the resistors near the tone control are - according to the picture - 27k and not 47k.

Thanks again for the hint, you are right.

Sorry, one more fault.

The half voltage filter capacitor is 100uF not 10uf.
The half voltage filter capacitor at the Locobox Distortion 10uf.

The 47k resistors in the tone control are still wrong. They should be 27k, according to your pictures.

tube-exorcist wrote:The 47k resistors in the tone control are still wrong. They should be 27k, according to your pictures.

Thanks a lot for having a closer look at.
Sorry, I must be blind while tracing.
I hope got it now.

47pF - first transistor base to ground, drive pot terminal 2 to ground, output transistor 10u to 220k to ground and 1k out, at montage schematic Vref 10u reverse polarity.

apollomusicservice wrote:47pF - first transistor base to ground, drive pot terminal 2 to ground, output transistor 10u to 220k to ground and 1k out, at montage schematic Vref 10u reverse polarity.

Thanks a lot for your assistance.

missing 1N914 reverse polarity protection diode and negative terminal from DC jack

apollomusicservice wrote:missing 1N914 reverse polarity protection diode and negative terminal from DC jack

Thanks again,
Diode is added.

Drawing error in the switching control part fixed.