A simple distortion effect box could use checking.

[TonyAme]

Hello,
I'm working on a simple effects distortion box for guitar, based on the Elektra Distortion circuit. I could use some others opinions and advice.

1. I have 2 pairs of diodes used for clipping the signal on the output, one pair will be silicon, the other pair will be germanium. Would my selector swith (SPDT toggle) work the way I think it will, selecting one pair (silicon), or the other (germanium)?

2. Also if anyone can point out any problems I might have with the basic layout. *The P-Channel MOSFET is used for reverse polarity protection.

3. I added extra connections to the 3PDT footswitch in case I need to change the wiring of the switch.

Sincere thanks for any help, advice.
Tony

 

[AnalogKid]

The SW1 diode switching is not correct. Notice that when the switch is in the upper position as shown, D2 and D3 still are in parallel across VR1. Expand SW1 to DPDT, and switch both sides of the diode networks.

Add a resistor from the Q2 drain to source, to assure a rapid and complete turn-off.

There are two "D1"s on the schematic.

Since either R5 or R6 always is in the circuit, you can eliminate one of them and move the other to the left side of SW1 (after C3).

ak

 

[TonyAme]

The SW1 diode switching is not correct. Notice that when the switch is in the upper position as shown, D2 and D3 still are in parallel across VR1.

Yes, I see it now. Thank you for bringing that to my attention, really appreciate it.

 

[TonyAme]

Updated schematic with corrected diode pair switching. Sincere thanks.
Tony

 

[AnalogKid]

I must correct myself. With the re-drawn schematic (and the removal of R3), it is clear that SW1 can go back to being a SPDT switch.

To paraphrase MacGuyver: A good schematic will always get you where you want to go.

ak

 

[TonyAme]

I must correct myself. With the re-drawn schematic (and the removal of R3), it is clear that SW1 can go back to being a SPDT switch.

To paraphrase MacGuyver: A good schematic will always get you where you want to go.

ak

Oh boy... I feel embarrassed. Thanks again for that. I was looking at the attached schematic from (freestompboxes.org) when I updated mine (above, with the DPDT switch.) An interesting/versatile way of wiring the clipping diodes.

 

[TonyAme]

Updated Electra Distortion-type schematic, with tone control and spdt clipping diode switching. Thanks.