DOD Distortion + ..........

[Banjotaz]

I love the sound of this DOD mod I did. The DOD 250 and the MXR Distortion + are basically the same circuit. The MXR has 1N270 germanium diodes for more clipping and the DOD has the 4148 diodes for less clipping and more headroom. Also the MXR uses the 741 OP Amp and the DOD has the 4558 amp. I like the sound of the 4558 chip with the 1N270 diodes { this is also what the Ross distortion has} so I put those diodes in my DOD. Since those diodes reduce the amount of volume and headroom coming out of the unit I changed the output resister to 10K { it was 100K- {this is the re-issue I'm using} I also changed the incap to .005 {from .01} to eliminate low end mush. The 250 also has an oscillation cap in the negative feedback loop which you can increase to roll off some more high end, or you can increase the vallue of the cap around the diodes to cut the shrill. I added a switch to my tone roll of cap 'cause at high gain it sounds better rolled off and at low gain it sounds more defined WITH the high end. All in all I really like this combination of parts and the 250 is a great pedal to mod! :wink:

[petemoore]

So do I !
 I found a 100k output pot to about right and louder than a 10k tho, and as far as cap mods they're in there and I forget the values, it is best anyway to find the values that work best for you and your equipment.
 But the 4558 is the OA of choice, and swaps of IC in this circuit do alter it's sound!. I think it sounds smoother grungier with the Ge clipping diodes. Two on one side/one on the other [back to back] or one/one sounds good...whatever is working for your setup is what it Should be.

[Banjotaz]

When I talked of the output resister I didn't mean the pot. I was talking about the actual resister before the diodes. This raises the volume with less resistence and lowers it with more.

[Joe Hart]

But won't you get different amounts of clipping when the signal goes over the diodes? Higher aplitude should clip off more of the signal "tops" and give you a more distorted sound. Maybe increasing the clipping threshold along with increasing the signal (by decreasing the resistance)? But I'm no EE, so...
-Joe Hart