# Promethium Distortion Mods?



## Bigshredder (Mar 21, 2021)

Hi,

I have built the Promethium Distortion last night and it sounds to undefined and the distortion is sort of uneven. I have the MIJ HM-2 and when the gain knob is raised on the original, the distortion is consistent during a chord. But with the Promethium Distortion it sounds like the chord is hitting it to hard initially and then backs off to fast making the sound a bit oscillating (maybe the wrong word?). And when I grind on it the old school death metal style some notes isn’t audible. It’s like there is to much bass and it’s overpowering all the other notes making it to muddy. I did an a/b test yesterday with the original HM-2 and the Promethium Distortion is more dynamic without the distortion engaged and has more bass pass through but it has an sort of ”3D chorus fuller sounding” feel to it. Is there some components I can change in order to make the distortion a bit “tighter” and maybe less bass hitting the distortion or something? I have tried different toneshaping pedals in the chain before the prom.distortion to give it less bass and distortion coming from another pedal and it sounds better to have a pushed drive pedal before (as with the original) but as soon as I engage the distortion in the prom.dist the distortion act kind of ugly. 
any tips is appreciated 
Thanks.


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## Betty Wont (Mar 21, 2021)

Sounds like something is wrong with your build. Try posting a troubleshooting report.


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## Bigshredder (Mar 21, 2021)

_I actually don’t think there is anything wrong with the build, I think it’s just to much bass passing through the distortion making it kinda muddy and overpowering. So I thought I could ask if there sin any easy replacement on some resistors or caps to make the distortion less fuzzy and maybe to cut more bass when it hits the gain. _


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## Chuck D. Bones (Mar 26, 2021)

I don't get it.  Your build should sound like the original (within component tolerances) and you say it doesn't.  Can you explain that?


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## Bigshredder (Mar 26, 2021)

I did explain in my post. And it does not sound like my original. More bass, less even distortion etc.


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## zgrav (Mar 26, 2021)

Bigshredder said:


> I did explain in my post. And it does not sound like my original. More bass, less even distortion etc.


That is why folks are suggesting that there may be something off in your build.  You could have a wrong part value already on the board and it is making it sound different from the original even if the pedal is otherwise working.


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## mnemonic (Mar 28, 2021)

Reducing the input caps should reduce the bass going into the pedal. Might be easier to first put an eq in front to see if reducing bass at the input will do what you want though.

I was playing around with mine the other day (I don’t use it that much) and decided to compare it to my behringer HM2 copy (I don’t have a real one) and it was noticeably harsher than the behringer which could get smoother if the mid/treble knob wasn’t turned up high. The character of the distortion of the promethium seemed more harsh and grating. They sounded real similar with the distortion at 0 though.

on a whim I tried plugging the promethium into a 12v power supply, and it suddenly sounded way more similar to the behringer, much more pleasant overall (pleasant for an HM2 circuit).

i did sub in a j201 for the (I think) 2n5457 since I forgot to order them when I got parts to build the pedal, and since the j201 worked I never bothered to order the right part. Maybe that is why they sound different or maybe I made an error when building it, or maybe some part difference between the pedals is to blame.


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## music6000 (Mar 28, 2021)

Bigshredder said:


> Hi,
> 
> I have built the Promethium Distortion last night and it sounds to undefined and the distortion is sort of uneven. I have the MIJ HM-2 and when the gain knob is raised on the original, the distortion is consistent during a chord. But with the Promethium Distortion it sounds like the chord is hitting it to hard initially and then backs off to fast making the sound a bit oscillating (maybe the wrong word?). And when I grind on it the old school death metal style some notes isn’t audible. It’s like there is to much bass and it’s overpowering all the other notes making it to muddy. I did an a/b test yesterday with the original HM-2 and the Promethium Distortion is more dynamic without the distortion engaged and has more bass pass through but it has an sort of ”3D chorus fuller sounding” feel to it. Is there some components I can change in order to make the distortion a bit “tighter” and maybe less bass hitting the distortion or something? I have tried different toneshaping pedals in the chain before the prom.distortion to give it less bass and distortion coming from another pedal and it sounds better to have a pushed drive pedal before (as with the original) but as soon as I engage the distortion in the prom.dist the distortion act kind of ugly.
> any tips is appreciated
> Thanks.


Show Good Pictures of the Components on your PCB.
 As Chuck said, It should sound like the Original.


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## Bigshredder (Mar 28, 2021)

Thanks for all your answers  
The pedal sounds good and nothing is wrong with it. It just has a bit too much low end and fizzy top end. It has less mids in the distortion than the original and when you grind it has less separation than the original. But it’s 2 different beasts


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## music6000 (Mar 28, 2021)

Bigshredder said:


> Thanks for all your answers
> The pedal sounds good and nothing is wrong with it. It just has a bit too much low end and fizzy top end. It has less mids in the distortion than the original and when you grind it has less separation than the original. But it’s 2 different beasts


I repeat :
Show Good Pictures of the Components on your PCB.
As Chuck said, It should sound like the Original.

different beasts = different components?


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