modding dod fx53

[arawn]

I have a dod fx 53 that's kind of tired and was thinking of modding it to change or cut the amount of distortion, it has always been a little more than i wanted.

I was thinking of replacing q1 and q2 with mpf102's and perhaps swapping  the d7 diodes for red led's, thought's? suggestions?

[soulsonic]

Replacing Q1 and Q2 with MPF102s most likely won't do anything to change the sound because they're used only as switches in this circuit and don't contribute to the quality of the distortion in any tangible way. Swapping the clipping diodes for LEDs will definitely do something to change the character of the distortion.

Changing the 680 ohm resistor that's connected between the Distortion control and the 1uF cap will change the gain of that stage and the amount of distortion it can generate. Higher values here will lower the gain. Try a 2.2K or maybe a 4.7K here. Or maybe even a 10K. You could put a 10K trim pot there to give a preset "maximum" gain setting - that would probably be the easiest way to tweak the gain there.

[runmikeyrun]

i would agree.  Lift the clipping diodes after the "distortion" stage before the "tone" stage.  Be prepared for a volume boost!  LEDs would be a good compromise of volume and clipping.  It is also going to change the tone so be aware of that.

You could also change the clippers to something softer like germanium for less edge and more of a fuzzy tube overdrive sound.  Experiment with them in both/either locations.

[arawn]

cool stuff to consider, I just was under the impression that 102's were lower gain and could alter the character! But I think I'll try your suggestions

[arawn]

I did it but i put in a dpdt for the gain resistor and can have two different resistors there, also makles them a little easier to change  It sounds great too!!

[soulsonic]

Cool! What values did you end up using?

[arawn]

a 340 and a 2.2k
it makes it seem quite a bit brighter now almost glassy and more tubelike to me esp with the 3mm leds.