You can call this one verified. I subbed the mpsa18's with 2n5089's and it sounds absolutely righteous, however there is a slight squeal that may or may not suit some peoples liking. that being said I'm going to box this one up for sure. Thanks for the layouts fuzzhead.
If anyone wants to make the board mounted trimpots into external knobs, I'll bet it would be real easy to do. "Input" and "Filter" are most likely just "gain" and "tone". You could remove the Input trimmer, then move the jumper that is in column one over to column seven, freeing up column one to wire an A1M potentiometer to. And it looks like you would only have to do legs 2 & 3 since 1 & 2 are jumpered together on the board. On the other side of the layout, you could put legs 1 and 3 of a B10k Filter potentiometer on the pads above and below Volume 3, then just wire leg 2 of the Filter pot directly to leg 3 of the Volume pot.
BMP without diodes & the mid bump, I’m sure this’ll be pretty loud! Yea, I’m wondering why he used trim pots for gain & tone, those are the ones you’d want to adjust the most?
I'm sure that the trimmers on the original are set to give this effect a particular, distinct tonality. Sure it's a "muff" circuit but, as the "Doom" name implies, most likely intended to be big and wooly. You could probably achieve the same sound with fixed resistors but trim pots probably make it easier to not be picky about transistors.
It reminds me of the PedalPCB Quarantine fuzz circuit, that was loud & doomy too? But having that Input trimmer is a good idea for dialing out the squeal I’m sure this has at loud volumes. Anybody else buy that PCB? it was shaped like a coronavirus & had a face on the top side, kinda funny, but not funny back in 2020
I’m sorry, I meant the bias of Q2. If it’s as noisy as some people say it is online, it may be nice to add a gate pot to shut it up when you need to. Or maybe not. Just an idea. I like gated everything.
You can call this one verified. I subbed the mpsa18's with 2n5089's and it sounds absolutely righteous, however there is a slight squeal that may or may not suit some peoples liking. that being said I'm going to box this one up for sure. Thanks for the layouts fuzzhead.
ReplyDeleteupdate on the "squeal". I adjusted the trim pots a bit and it very much went away, and very much sounded like some of the demos. thanks again!
DeleteIf anyone wants to make the board mounted trimpots into external knobs, I'll bet it would be real easy to do. "Input" and "Filter" are most likely just "gain" and "tone". You could remove the Input trimmer, then move the jumper that is in column one over to column seven, freeing up column one to wire an A1M potentiometer to. And it looks like you would only have to do legs 2 & 3 since 1 & 2 are jumpered together on the board. On the other side of the layout, you could put legs 1 and 3 of a B10k Filter potentiometer on the pads above and below Volume 3, then just wire leg 2 of the Filter pot directly to leg 3 of the Volume pot.
DeleteBMP without diodes & the mid bump, I’m sure this’ll be pretty loud! Yea, I’m wondering why he used trim pots for gain & tone, those are the ones you’d want to adjust the most?
DeleteThanks for verifying.
DeleteI'll add a layout with external Input and Filter controls shortly...
I'm sure that the trimmers on the original are set to give this effect a particular, distinct tonality. Sure it's a "muff" circuit but, as the "Doom" name implies, most likely intended to be big and wooly. You could probably achieve the same sound with fixed resistors but trim pots probably make it easier to not be picky about transistors.
DeleteIt reminds me of the PedalPCB Quarantine fuzz circuit, that was loud & doomy too? But having that Input trimmer is a good idea for dialing out the squeal I’m sure this has at loud volumes. Anybody else buy that PCB? it was shaped like a coronavirus & had a face on the top side, kinda funny, but not funny back in 2020
DeleteIt’s apparently pretty noisy. Might be useful to add a trimmer on Q3 to get a bit of a gate. A muff with one big volume knob is pretty cool.
ReplyDeleteI’m sorry, I meant the bias of Q2. If it’s as noisy as some people say it is online, it may be nice to add a gate pot to shut it up when you need to. Or maybe not. Just an idea. I like gated everything.
Delete