# Distortion 250 Parts Values



## thesmokingman (Feb 28, 2022)

Thought I might straighten this one out a little as the build doc is entirely Distortion+

MXR Distortion+
Resistors:
R1 - 10K
R2 - 1M
R3 - 4K7
R4 - 10K
R5 - 1M
R6 - 1M
R7 - 1M
R8 - 4K7*

Capacitors:
C1 - 1n
C2 - 10n
C3 - 47n
C4 - 1u
C5 - 1n
C6 - 1u
C7 - 47u*

Semiconductors:
IC1 - LM741
D1 - 1N270
D2 - 1N270
D3 - 1N5817*
LED*

Potentiometers:
Volume - A10K
Gain - B1M

* - not in original units, recommended for indicator LED and better power supply filtering

DOD 25O

Resistors:
R1 - 10K
R2 - 1M
R3 - 4K7
R4 - 10K
R5 - 470K
R6 - 22K
R7 - 22K
R8 - 4K7*

Capacitors:
C1 - omit**
C2 - 10n
C3 - 47n
C4 - 4u7 electrolytic
C5 - 1n
C6 - 10u
C7 - 47u*


Semiconductors:
IC1 - LM741
D1 - 1N4148
D2 - 1N4148
D3 - 1N5817*
LED*

Potentiometers:
Volume - A100K
Gain - C500K

* - not in original units, recommended for indicator LED and better power supply filtering
** - some have it, some don't. those that do, have 2n2.

There are other small bits out there depending on the vintage of the 25O in question ... op amps, feedback loop cap in parallel with the 1M resistor, clipping diodes, etc ... there's a table of all this crap floating around the webs that can help should you want to get very era specific.


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## Coda (Feb 28, 2022)

What about the Ross?


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## thesmokingman (Feb 28, 2022)

Do you really want the Ross distortion? I ask because the original used a dual op-amp (4558) with better noise rejection and slew rate than the 741


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## Coda (Feb 28, 2022)

Well, I figured since you usually see the three lumped together...


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## thesmokingman (Feb 28, 2022)

Coda said:


> Well, I figured since you usually see the three lumped together...


tan or black? I can do this all day


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## Dan M (Feb 28, 2022)

Yes.


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## thesmokingman (Feb 28, 2022)




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## Big Monk (Feb 28, 2022)

thesmokingman said:


>



It’s gotsta be Smithwick’s and Guinness!


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## thesmokingman (Mar 1, 2022)

Ross Distortion (tan)
Resistors:
R1 - 10K
R2 - 1M
R3 - 4K7
R4 - 10K
R5 - 1M
R6 - 1M
R7 - 1M
R8 - 4K7*

Capacitors:
C1 - 1n
C2 - 10n
C3 - 47n
C4 - 1u tantalum
C5 - 1n
C6 - 1u tantalum
C7 - 10n

Semiconductors:
IC1 - 4558**
D1 - 1N270
D2 - 1N270
D3 - 1N5817*
LED*

Potentiometers:
Volume - B50K
Gain - C500K

* - not in original units, recommended for indicator LED and better power supply filtering
** - 4558 is dual op amp, it has better noise rejection and slew rate than the 741. TL071, TL081, LF351 should work fine as a substitute

Ross Distortion (black)
Resistors:
R1 - 10K
R2 - 1M
R3 - 4K7
R4 - 10K
R5 - 1M
R6 - 1M
R7 - 1M
R8 - 4K7*

Capacitors:
C1 - 1n
C2 - 10n
C3 - 47n
C4 - 1u tantalum
C5 - 1n
C6 - 1u tantalum
C7 - 10n

Semiconductors:
IC1 - 4558**
D1 - 1N4148+1N4148
D2 - 1N4148
D3 - 1N5817*
LED*

Potentiometers:
Volume - B50K
Gain - C500K

* - not in original units, recommended for indicator LED and better power supply filtering
** - 4558 is dual op amp, it has better noise rejection and slew rate than the 741. TL071, TL081, LF351 should work fine as a substitute


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## Paradox916 (Mar 1, 2022)

Dan M said:


> Yes.
> View attachment 23598


I want one!…or 4…


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## cdwillis (Mar 2, 2022)

If somebody hasn't built one of these, make sure to get a c500k pot for gain. The b1m was almost unusable with most of the gain being concentrated in that last 10% of the sweep. The c500k pot has a nice smooth overdrive increase as you turn it up.


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## thesmokingman (Mar 2, 2022)

or C1M ... which is what I would do if I were building a distortion+


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## Coda (Mar 2, 2022)

thesmokingman said:


> or C1M ... which is what I would do if I were building a distortion+



Yea, but what does JHS use?…


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## music6000 (Mar 2, 2022)

Something Like This:


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## thesmokingman (Mar 2, 2022)

Coda said:


> Yea, but what does JHS use?…


does it matter? I mean getting in a twist about the big box 25O just shows how little attention gets paid ... there's been gut shots of it on the fx database for well over a decade along with discussion at the usual places


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## thesmokingman (Mar 2, 2022)

thewintersoldier said:


> In all these 250 threads you have been the only voice of logic. View attachment 23654


I'm reminded of the South Park episodes about the little girl that was actually an advertisement ...


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## thesmokingman (Mar 4, 2022)

MXR Micro Amp
Resistors:
R1 - 1K
R2 - 56K + 47p capacitor in parallel
R3 - 2K7
R4 - 470R
R5 - 10M
R6 - 100K
R7 - 100K
R8 - 4K7*

Capacitors:
C1 - 22M Resistor
C2 - 100n
C3 - 4u7
C4 - 15u
C5 - omit
C6 - 1u
C7 - 47u*

Semiconductors:
IC1 - TL061
D1 - 10K Resistor
D2 - either board out at anode pad or jumper anode pad to Volume wiper pad
D3 - 1N4001**
LED*

Potentiometers:
Volume - omit
Gain - C500K

* - not in original units, recommended for indicator LED and better power supply filtering
** - can remain 1N5817 per build doc


This one's a bit of a bear because of the large-value-by-comparison electrolytics involved vs the layout. You could probably do a MLCC for C3 and either 10u or 22u for C4. 22M is also a ridiculous resistor value, so 10M is probably the limit on what anyone would reasonably have lying around.


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## Feral Feline (Mar 5, 2022)

Next up, thesmokingman, you should do the Armstrong Blue Clipper, it’s got a weird anomaly resister that required my drilling a hole in my PCB to break a trace to accommodate the resister, but other than that it has the same topology.


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## thesmokingman (Mar 5, 2022)

Dan Armstrong Blue Clipper
Resistors:
R1 - jumper + 240K from either pad (not both) to C1 ground pad
R2 - 150K
R3 - 2K4
R4 = 8K2
R5 - 20K
R6 - 1M*
R7 - 1M*
R8 - 4K7*

Capacitors:
C1 - omit
C2 - 47n
C3 - jumper
C4 - 4u7
C5 - omit
C6 - 1u*
C7 - 47u*

Semiconductors:
IC1 - 4558 **
D1 - 1N914
D2 - 1N914
D3 - 1N5817*
LED *

Potentiometers:
Volume - A50K + 33n across pot solder lugs 1 and 3. 10K resistor  between board and pot lug 3***
Gain - omit potentiometer + 4u7 capacitor between pad 2 and 3

* - I couldn't find a schematic addressing power supply so I left the values in place from the Distortion 250 build document.
** - 4558 is dual op amp, it has better noise rejection and slew rate than the 741. TL071, TL081, LF351 should work fine as a substitute
*** - This was the "no trace cut, no drilling" method I chose to get there. probably best built on solder lug pot.

I'd definitely double check my work on this one, especially the power supply


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## Feral Feline (Mar 7, 2022)

Big Monk said:


> It’s gotsta be Smithwick’s and Guinness!




​




​😸


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## HamishR (Mar 8, 2022)

I know there are players who swear by the Distortion 250 etc - but they never did anything for me. A friend once took me to a guitar store especially to try one, like it was the holy grail of ODs. I tried it through some amp that had built-in overdrive without realising and thought - wow, that sounds pretty good!  But the pedal wasn't on. So he switched to the clean channel and turned on the D250 and looked at me expectantly... Oh dear. Sorry, I think it just sounds thin and buzzy! Can we try the dirt channel on the amp again?

There has to be a way of using it which sounds great otherwise why would people still be building them?


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## music6000 (Mar 8, 2022)

Dan M said:


> Yes.
> View attachment 23598


Something like This:


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## thesmokingman (Mar 8, 2022)

ew


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## music6000 (Mar 8, 2022)

music6000 said:


> Something like This:
> View attachment 23880


Black & Tan Limited Edition Overdrive Preamp


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## Dan M (Mar 8, 2022)

Only if the switch is: 
1. Black 
2. Tan
3. A “secret” middle position like on a Behringer SF300 that gives “Black & Tan”


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