DEMO Promethium

This post contains an audio or video demo

Guardians of the analog

Well-known member
Build Rating
5.00 star(s)
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I want to preface and say that I apologize if you find my build reports as of late to be wordy, it's not my intent to ramble but I don't find one sentence very helpful. I also do not want to pretend I write for a food blog and describe a pedal as delicious or tasty, also not very helpful. I'm not trying to step on @MichaelW toes, no one could replace the Micheal Crichton of pedalpcb 🙏🙏🙏.

This pedal was one that I was always on the fence about building. It wasn't really on my radar as I felt it was a one trick pony. I don't play swedish death metal and every demo that you hear is THAT sound. It never really sounded good in demos, especially in isolation. There are two main reasons I built this pedal. One is @Harry Klippton , the master of the HM-2 has built a couple of these and has two originals and his praise was enough for me to give it a try. Two, I don't see a lot of build reports for this. It sells, I see troubleshooting threads, but not many build reports. So, I had to build one to assess for myself.

@Robert was I believe at the time this project was originally released, the only other person besides byoc to offer a board for this project. Now Aion does as well but this is a much better layout. Props for using modern easily accessible components as well, unlike byoc who makes you look for hard to find expensive and inferior sip opamps. Also, this was possible thanks to Will coming in clutch with the 1.5uf cap😘. As usual with a ppcb project, the build was simple and smooth, so nothing new there. So how does it sound?

It's decedent 🤣. This is not the one trick pony I hear in every video on YT. It's far more versatile than I imagined. The gain range, while not having the widest range, is fine for a distortion that is made for metal. It can do some excellent med gain type sounds as well, but no one is building this for classic rock. As Will said, it's ragged but cuts. This is spot on. It's heavy and chugs in the bottom end but it's not blown out, and the mids are very cutting giving it a very pronounced EQ to sit in a mix. The gyrator EQ section is brilliant in execution, whoever designed this knew what they were doing. If I had to describe it I would say it's like a DS-2 with balls. Credit to @Paradox916 for his Photoshop skills.
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For my enclosure I went with a matte black tayda enclosure with UV printing. My color scheme is based on the classic HM-2 palette. My inspiration for the artwork is a play off the promethium name. @peccary and I were discussing our love of ancient Greek, Roman and Norse mythology and riffing on the the tales of Promethium, the god of fire. I chose the skull of Surtur, a fire god in Norse mythology and the bringer of Ragnarok in the third Thor movie. I used the Thor Ragnarok font as well to tie it all together. Overall I'm really happy with the end result and see lots of use out of this pedal. The quick sound clip is from the pedal's POV and shows one of my favorite settings. Also in the clip is a future build report that I was testing with the pedal. For reference, the pedal is going into my blackface set clean with my HB SG.

TL DR, this pedals Fux and you should build it.
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I guess I "detective'd" correctly. I think you are almost at the point where to improve on neatness you are gonna have line up component bodies with a straight edge. Please don't go that far, that would be madness.

I hope this Boss tribute series is bringing the diversion from the day to day we all sometimes need and that your day-to-day is improving. I know I am looking forward to continuing additions in the series. Amazing work.
 
I guess I "detective'd" correctly. I think you are almost at the point where to improve on neatness you are gonna have line up component bodies with a straight edge. Please don't go that far, that would be madness.

I hope this Boss tribute series is bringing the diversion from the day to day we all sometimes need and that your day-to-day is improving. I know I am looking forward to continuing additions in the series. Amazing work.
I still have so many areas to work on, I see so many little things that drive me crazy. At a certain point you gotta just let go and move on. And using a straight edge would be madness, not all caps are the same size. Good look on the sleuthing.
This exact thought had passed through my head a few times…

Now I have to… hold my beer….
Only you would take that as a challenge. He stuck a soldering iron in one eye, hold my beer, I'll do both eyes. That'll show em.
 
I still have so many areas to work on, I see so many little things that drive me crazy. At a certain point you gotta just let go and move on. And using a straight edge would be madness, not all caps are the same size. Good look on the sleuthing.

Only you would take that as a challenge. He stuck a soldering iron in one eye, hold my beer, I'll do both eyes. That'll show em.
What can I say I’m simple minded and easy influenced 🤣
 
Your video auto played on my YouTube today at work. I saw the guardians symbol and got excited. You have peaked my interest. Also not really into the chainsaw but I am now curious. I thought I had cut the list down a bit but it is quickly getting longer again.
 
he's good at that, when it's serious.. he can make a mean pedal, run it through the paces and tell you what ya need to know!

where di d you get the op amps you used? my 72's were.. meh to nonexistant and some 4558(like the aion's choice) turned aa bit ... touchy
 
Your video auto played on my YouTube today at work. I saw the guardians symbol and got excited. You have peaked my interest. Also not really into the chainsaw but I am now curious. I thought I had cut the list down a bit but it is quickly getting longer again.
Every time is say I'm done, there goes one more 😂💸💸💸
he's good at that, when it's serious.. he can make a mean pedal, run it through the paces and tell you what ya need to know!

where di d you get the op amps you used? my 72's were.. meh to nonexistant and some 4558(like the aion's choice) turned aa bit ... touchy
I've been buying a lot of ICs at @StompBoxParts these days. Their selection is always expanding, never worry about out of spec/fakes, good prices and fastest shipping.
 
think they were from SBP... might have been Amp parts, I have 4 places I get most IC's from, and other 2 are Mouser or Digi-Key.. nice thing about sockets, I can put a diff set in!
This was my thought as I assembled my MBP 1590A hotcake. Little did I realize that the socket puts my chip up just a few mm beyond the caps and.... well .... sockets aren't always your friend.
 
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