Jovi Bon Kenobi
Well-known member
Oh wow I love the sound of this one! I built it to 70s gray box specifications with the help of Mr. PedalPCB.
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Distortion 250 (Gray Specs)
- Thread starter Jovi Bon Kenobi
- Start date
geekmacdaddy
Well-known member
sweet and neat
Chuck D. Bones
Circuit Wizard
Very clean.
K Pedals
Well-known member
Nice!!!
What are the substitutions???
Jovi Bon Kenobi
Well-known member
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*
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*
K Pedals
Well-known member
Thanks!!!
Mourguitars
Well-known member
Earth Rocker
New member
Nice! A good example for a beginner like me to reference. I'm actually doing this build right now but according to the build docs. I'll have to try this variation on a later build. I noticed you used a 1uF electrolytic. Is that for this variation that you did on this build? I used a 1uF poly film box in that spot. Will that work or did I make a mistake?
Jovi Bon Kenobi
Well-known member
Thanks! You'll be fine. Thats a 22uF in the 1uF silkscreen spot, as the mod suggests. I just followed PedalPCB's list to turn it into gray DOD specs. Following the build docs I believe it's closer to a Distortion+.
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Earth Rocker
New member
Mourguitars
Well-known member
Mourguitars
Well-known member
Can you swap out the A10k to A100k to add more volume on the reg 250/distortion with out the other mods ?
Mike
Mike
Jovi Bon Kenobi
Well-known member
Someone else with more electronics knowledge will have to chime in here. I just added the a100k because that's what all the gray spec mods I found on the interwebs suggested and what was posted above from Mr PedalPCB was very similar to everything I found (minus the a10k) so I went with it. It works perfectly and sounds great.
Chuck D. Bones
Circuit Wizard
Changing the VOLUME pot from 10K to 100K won't increase the volume. The diodes will get hit a little harder, that's all. If you want more volume, your best option is to put a booster after the Distortion 250. You can change the diodes to silicon or LEDs, or stack 1N270s to get more volume, but any of those changes will alter the sound.
One a slightly different topic, if you socketed the opamp, you might try other single opamps to see if you like their sound. 741's are shitty little opamps IMHO. They are not low-noise by any stretch of the imagination. They were used in vintage pedals because they were cheap and there were not a lot of options back in the day.
One a slightly different topic, if you socketed the opamp, you might try other single opamps to see if you like their sound. 741's are shitty little opamps IMHO. They are not low-noise by any stretch of the imagination. They were used in vintage pedals because they were cheap and there were not a lot of options back in the day.
Mourguitars
Well-known member
I found this in searches, my thought it may come in handy , ill swap out a few IC's
People like running a 10 band EQ after the 250 Dist + like Randy Rhoads did...ill try a clean boost as well
People like running a 10 band EQ after the 250 Dist + like Randy Rhoads did...ill try a clean boost as well
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Jovi Bon Kenobi
Well-known member
Nice link. Though those are all dual op amps and I'm pretty sure it won't work in the 250 because it needs a single op amp.
IC op-amps characteristics
So since there are so many op-amps (dual, low noise) that you can try in the IC socket of your favorite OD pedal, I decided to write down how I would describe their characteristics so you can decid…vanespedalsandpickups.wordpress.com
I found this in searches, my thought it may come in handy , ill swap out a few IC's
People like running a 10 band EQ after the 250 Dist + like Randy Rhoads did...ill try a clean boost as well
Mourguitars
Well-known member
Oh man great catch..i took it down don't want anyone to fry their pedal...Thanks JBK
Mike
Mourguitars
Well-known member
ElectroSmash - MXR Distortion + Circuit Analysis.
The M-104 MXR Distortion + aka Distortion Plus aka D+ is a distortion guitar pedal designed by MXR and released between 1978 and 1979. The original stompbox did not have external power jack or indicator LED. Jim Dunlop bought the MXR licensing
This is a good read..im starting to understand things a little more it broke down what parts are in the clipping stage , Op amp stage and Power supply stage
Bookmarked that link JBK
Mike
