Promethium - HM-2 - The Swedish Chainsaw

[jcpst]

Build Rating

5.00 star(s)

This was actually one of my early builds that didn’t work. I still had the enclosure, and big ass orange knobs, so I finally revisited it.

On the original PCB I spent a good amount of time troubleshooting. The board looked like crap after my original n00b build and swapping parts, so I picked up a new PCB a few sales ago. I salvaged some parts like Ge diodes from the first build.

I decided to do an epoxy pour on this one and it was the worst in the batch, but decided I could live with it. My audio wires were a bit short, but that’s fine too.

This thing almost doesn’t need any pots. The classic sound is everything dimed. It definitely had me black metal riffin’.

But I learned this pedal has another use! Leave everything dimed, turn the gain all the way down, switch to single coil neck pup. Works as a great dirty boost.





Post Post Addendum: I think it would be cool to have a version of this with just a volume knob and an on/on toggle. The bass and treble would be at max, and the toggle would be gain minimum/maximum. To switch between boost mode and chainsaw mode.

 

[Bret608]

Those knobs are amazing! Exactly what I would want for an HM-2 build. Glad you persevered on it!

 

[Feral Feline]

Love this Chainsaw Build.

That style of orange-topped knob looks great!



Suggestion for the next minimalist build of this circuit:
Instead of the toggle, have a 4PDT foot-stomper:

• Pole 1 (assuming the gain toggle was to be a SPDT) still handles the gain swap
• Poles 2&3 swaps out the master volume for a second volume pot (could be wired up to an internal set&forget trimmer, stacked concentric knob, or whatever you want).
• Pole 4 (LED indication of "channel".

Two footswitches and a big ol' knob(s).

 

[jcpst]

Love this Chainsaw Build.

That style of orange-topped knob looks great!



Suggestion for the next minimalist build of this circuit:
Instead of the toggle, have a 4PDT foot-stomper:

• Pole 1 (assuming the gain toggle was to be a SPDT) still handles the gain swap
• Poles 2&3 swaps out the master volume for a second volume pot (could be wired up to an internal set&forget trimmer, stacked concentric knob, or whatever you want).
• Pole 4 (LED indication of "channel".

Two footswitches and a big ol' knob(s).

OR… (and please let me know if you read and see holes in this idea)

Two intelligent relay DPDT modules, hooked together on the ctrl pads and set them to channel switching mode. So only one cn be active at a time.

Then, wire each switch like this. One for MIN GAIN, the other switch for MAX GAIN.



The relay modules have pads for LEDs, so that saves a pole.

This does take switching the volume out of the equation.

HOWEVER! The apparent volume difference between min and max gain is not huge. For sure, max gain is louder, but min gain is already saturated. So leaving it at the some volume for both could work.

This way, you can switch between boost, chainsaw or bypass with one stomp no matter what.

EDIT: Upon further pondering, I think I still like your bypass stomp and A/B stomp better…

 

[Nostradoomus]

knob alignment making joe @ lone wolf jealous

 

[Feral Feline]

Like I told JamieJ recently, I'm just an old-school mechanical-electro guy.

What I know about you youngster-builders' relay-bypasses wouldn't fill the the gap between the legs of a SOT-23 JFET.



What I can tell you is that you'd want to use relays that rely on momentary-SPST stompers, you know the ones, they have but all of two fangs (lugs) — BUT...!!!

You use a DPDT momentary, or 3PDT momentary, or 4PDT momentary stomper (4Ps exist, I have a couple!) to control up to, respectively:
two relay switches, or three relay switches, and even four relays at a time!