Distortion 250 (Gray Specs)

[Chuck D. Bones]

ElectroSmash is a good site and most, but not all of the analyses are correct. There are some errors / omissions in the Distortion+ analysis, but for most part, it's correct. The opamp does most definitely clip the signal at moderate to high gain settings and the diodes do nothing to stop that. The input impedance calc is wrong, but it's close.

 

[Barry]

Great looking build as always

 

[cgreg714]

Thanks folks! Here are the gray spec subs from Mr. PedalPCB.

Add 25pF cap across R2

R3 47K
R5 470K
R6 20K
R7 20K

C1 2n2
C4 22u (positive lead in left pad)
C5 2n2
C6 10u

D1 1N4148
D2 1N4148

Gain C500K
Volume A10K *I used an A100k here*

Just out of curiosity, what does "add 25pF cap across R2" mean? I'd like to do this version of the build, but I'm new to all this and not sure what this mod means.

 

[Barry]

Just out of curiosity, what does "add 25pF cap across R2" mean? I'd like to do this version of the build, but I'm new to all this and not sure what this mod means.

You're going to wire it in parallel with R2

 

[BurntFingers]

Just out of curiosity, what does "add 25pF cap across R2" mean? I'd like to do this version of the build, but I'm new to all this and not sure what this mod means.

You can literally solder a 25pf cap to the resistors legs so they're in parallel. 1 leg each side. Just Google images for 'treble bleed' and you'll see.

 

[cgreg714]

You can literally solder a 25pf cap to the resistors legs so they're in parallel. 1 leg each side. Just Google images for 'treble bleed' and you'll see.

Thanks....the google images search cleared it up entirely.

 

[Mcknib]

Now that's a thing of beauty

 

[Route14]

Was the 25pf cap mounted on the resistor from under the board? I didn't see it in the pics.

 

[Jovi Bon Kenobi]

I sold it ages ago and forgot already, but zooming in close I can see two leads poking through R2's pads so I'm gonna have to say yes