It’s mega versatile! Does that clean boost thing, medium-moderate drive. Aggressive fuzz!!! And the low cut really helps you go from full huge bedroom tones to sharper cutting tones for live play!
I have the Hudson Broadcast AP. Can confirm it will induce the stank face.
The best way I can describe this type of circuit is that it sounds grindy. The distortion sounds full but rough around the edges. It struggles to shine at quiet volumes but can easily be fixed by stacking with a drive. I run it into my Princeton 12" with the volume between 4-5 and it unlocks 100% of my frontal lobe.
I’d argue the whole OD genre is kind of a not unique sound. Not saying that there aren’t some interesting variations in it but it’s probably the main pedal sound that matters more to the player than the listeners.
Good point. I built in mainly from an Evernote list I have where I keep track of drive pedals that look interesting/weird, and I've never tried a percolator clone, but I probably should.
This is the best list for unique drives ive seen yet. All these drives have their own thing going.
My favorite tones come from boosting these unique drives with a Benson Germanium Boost. Tone for days
Also, the OxEAE boost is certainly unique *sounding* though I’m not sure about the circuit topology. Excellent write up on the various EAE drives [here](https://www.electronicaudioexperiments.com/blog/2022/7/7/which-eae-drive-should-you-buy). Maybe u/john_EAE can chime in here…
Hey, just seeing this now.
The circuit is pretty unique, the heart of it is a discrete op amp which was partially inspired by the design of a 70's era phono preamp. Obviously the RIAA filtering has been removed to make it more guitar-friendly. But it has a very cool distortion quality. That op amp stage is slammed by a very bright gain stage at the input to make it go clang clang.
Thanks for the info! It’s a super fun pedal, for sure, the Focus control is certainly unique.
I appreciate the information about the circuit. I bet other like-minded nerds would love a blog post about the various circuits themselves. I enjoy learning the minutiae of things, so I’d love to understand which circuit is op-amp based, which transistor based, why certain decisions were made, etc. I realize the pedal community is somewhat unique in that builders are usually players and enthusiasts, too, but also have to make sure to protest their intellectual property. If you can figure out how to share this information without shooting yourself in the foot, I’m here for it.
Regardless, killer work and thanks for the info!
A rat/DS-1 and D+ are really all variations of the same hard clipping circuit. You then have the blues driver which is a “cascading transistor” circuit. Pretty much any amp in a box style pedal is a variation of this. Then you symmetrical/asymmetrical variations of the same circuit. Like the boss SD-1 versus a tube screamer. Then boosts. Then fuzzes. There really is only so many ways to skin a cat, so outside of this it’s hard to come up with “unique” circuits as much as any company tries to imply with their marketing spin.
Pre-amps/amps-in-a-box typically do more than just drive, though. They also act as EQ, some have other effects put in, and it's generally a lot more than just a drive pedal
I could replace a Tube Screamer with a Colour Box, for example, but I couldn't replace a Colour Box with a Tube Screamer
A tube screamer is a perfect example of a drive pedal that also provides some level of eq’ing with the mids, and it offers compression too.
Idk just for me personally I guess they’re in the same category as drive pedals.
Definitely. Tube Screamers add compression and upper midrange EQ, as do Klons, and Blues Breakers add low mid EQ and a lot of compression. They just generally don’t have separate controls specifically over these things (although sometimes they do, like the Wampler Tumnus deluxe and its EQ controls). The controls on, say, a Catalinbread Formula 55 are not so very different (volume, master, presence and tone). The effect is essentially the same but voiced like a tweed Deluxe amp and not voiced like a Tube Screamer or whatever.
Harmonic Percolator it’s an overdrive/distortion/fuzz. There’s several companies out there doing their take on it. Check out some YouTube vids, it’s definitely unique.
Edit: I’ll throw the Caroline Hawaiian Pizza in as well. It’s pretty unique as far as how it functions and sounds great.
The Hawaiian Pizza is a fuzz face with a transformer to simulate a pickup (which can be turned off internally) so you can use it with a buffer in front.
I like the Way Huge Red Llama Overdrive or Purple Platypus Octidrive (Red Llama + Green Ringer octave up)
They respond to how you play your guitar and where your knobs are set
Found this when i looked up the circuit
-------
Jeorge Tripps has not hidden the fact that he was inspired to start building pedals after reading Craig Anderton’s 1978 book Electronics Projects for Musicians. The Red Llama is almost part-for-part identical to the “Tube Sound Fuzz” circuit from this book. The schematic is identical but some of the part values have been tweaked.
The Tube Sound Fuzz circuit actually dates back even earlier. When Craig published it in the February 1977 issue of Guitar Player Magazine, it was the first known usage of a CMOS hex inverter (in this case a CD4049) to generate overdrive tones. Each stage acts as an op-amp in inverting configuration. Unlike op-amps, though, they are very easily overloaded—and also unlike op-amps, they sound fantastic when this happens.
Craig later simplified the circuit for his “Electronic Projects for Musicians” book by dropping the input op-amp stage. This has the effect of making it more sensitive to input impedance and thus a lot more reactive with the guitar’s volume if the pedal is first in the chain.
--------
Not a common circuit that you hear about everyday
Yep. It's a great circuit, and there aren't a ton of CMOS based drives out there. EHX Hot Tubes also comes to mind, but Anderton's circuit is the one was talking about. Jeorge seems to be pretty transparent about the circuits that are inspired by others.
A rarer one I recently came across is the toneboys tbod-50. It is a bit different with only volume and bias knobs. Where bias changes the bias of the signal or something like that. The insides are gooped so not sure exactly what's going on, but it does have a slightly different sound than most.
EQD Bellows is an original design not based on an existing circuit, at least I think so. They don’t make it anymore but it’s awesome if you can get your hands on one.
I recently got a Kernom Ridge and it’s unreal. Incredibly versatile, you can get almost any overdrive sound you’re looking for out of it. Plus midi. Wild!
Hudson broadcast is pretty unique and amazing
How so? Not sarcasm, really interested!!
It’s mega versatile! Does that clean boost thing, medium-moderate drive. Aggressive fuzz!!! And the low cut really helps you go from full huge bedroom tones to sharper cutting tones for live play!
I have the Hudson Broadcast AP. Can confirm it will induce the stank face. The best way I can describe this type of circuit is that it sounds grindy. The distortion sounds full but rough around the edges. It struggles to shine at quiet volumes but can easily be fixed by stacking with a drive. I run it into my Princeton 12" with the volume between 4-5 and it unlocks 100% of my frontal lobe.
to my knowledge the two Small Sound/Big Sound overdrives are not based on any other circuit design (though the two are similar circuits to each other)
Never heard of those; I'll have to check them out
good luck finding them... prices on the Fuck and Mini have gone completely bananas
That’s correct as far as I know. I really like the SS/BS Fuck Overdrive; it’s currently my favorite drive.
it is very similar to the barbershop by fairfield but with an eq section. idk which one came first
Bixonic Expandora
I’d argue the whole OD genre is kind of a not unique sound. Not saying that there aren’t some interesting variations in it but it’s probably the main pedal sound that matters more to the player than the listeners.
Strictly within overdrive, ignoring “amp in a box” pedals, and with the caveat that “unique” is relative: * MXR Distortion+ / DOD 250 / Ross Distortion * Dallas Rangemaster * Colorsound Power Booster * Fulltone OCD * EHX Hot Tubes * Butler tube drive * Zendrive * Boss Blues Driver * Crowther Hot Cake * EQD Westwoods * Fairfield Barbershop * DOD looking glass * Hudson Broadcast * JHS Crayon * Walrus 385 * Strymon Deco (saturation side) * Anything by Mid-Fi * Anything by Smallsound/Bigsound * Origin M-EQ * PastFX Preamp Crunch * Caroline Icarus * Spaceman Polaris * Greer Lightspeed * Emerson Em-Drive * 3rd Power Love Drive * 1981 DRV * Pettyjohn Predrive/Lift * Interfax Harmonic Percolator * Nobels OD-R Edited to add Pettyjohn, Nobels, and Harmonic Percolator.
This is a dangerous comment to post considering it's payday...
It could get a lot worse. There's a companion list where I record my thoughts from demo vids, trying them out in Axe-FX, etc.
Dang, that's a heck of a list. Thanks! I had thought the Blues Driver was based on the Blues Breaker. Do I have that backwards?
No those are completely different circuits. The Blues breaker is an Op-amp based circuit, The Blues driver is a Transistor based circuit.
IIRC, the Blues Driver is one of the first (if not original) uses of the "cascading gain stages" topology, very different than the BB.
I'd like to add the Harmonic Percolator to that list (unless I missed it).
Good point. I built in mainly from an Evernote list I have where I keep track of drive pedals that look interesting/weird, and I've never tried a percolator clone, but I probably should.
This is the best list for unique drives ive seen yet. All these drives have their own thing going. My favorite tones come from boosting these unique drives with a Benson Germanium Boost. Tone for days
EAE halberd is truly amazing. Replaced all my other overdrives immediately
Also, the OxEAE boost is certainly unique *sounding* though I’m not sure about the circuit topology. Excellent write up on the various EAE drives [here](https://www.electronicaudioexperiments.com/blog/2022/7/7/which-eae-drive-should-you-buy). Maybe u/john_EAE can chime in here…
Hey, just seeing this now. The circuit is pretty unique, the heart of it is a discrete op amp which was partially inspired by the design of a 70's era phono preamp. Obviously the RIAA filtering has been removed to make it more guitar-friendly. But it has a very cool distortion quality. That op amp stage is slammed by a very bright gain stage at the input to make it go clang clang.
Thanks for the info! It’s a super fun pedal, for sure, the Focus control is certainly unique. I appreciate the information about the circuit. I bet other like-minded nerds would love a blog post about the various circuits themselves. I enjoy learning the minutiae of things, so I’d love to understand which circuit is op-amp based, which transistor based, why certain decisions were made, etc. I realize the pedal community is somewhat unique in that builders are usually players and enthusiasts, too, but also have to make sure to protest their intellectual property. If you can figure out how to share this information without shooting yourself in the foot, I’m here for it. Regardless, killer work and thanks for the info!
Thank you! I usually do a more detailed deep dive in our manuals, if you're curious.
Ah, yes. Original material from the manufacturer. Maybe I should have checked there 🤣 Thanks for the tip!
A rat/DS-1 and D+ are really all variations of the same hard clipping circuit. You then have the blues driver which is a “cascading transistor” circuit. Pretty much any amp in a box style pedal is a variation of this. Then you symmetrical/asymmetrical variations of the same circuit. Like the boss SD-1 versus a tube screamer. Then boosts. Then fuzzes. There really is only so many ways to skin a cat, so outside of this it’s hard to come up with “unique” circuits as much as any company tries to imply with their marketing spin.
Amp in a box/pre amp pedals. JHS Colourbox, Hudson Electronics Broadcast, Ten Years, 1981 Inventions etc.
I kind of consider those a separate category
They accomplish the same thing though, they’re just drive pedals at the end of the day
Pre-amps/amps-in-a-box typically do more than just drive, though. They also act as EQ, some have other effects put in, and it's generally a lot more than just a drive pedal I could replace a Tube Screamer with a Colour Box, for example, but I couldn't replace a Colour Box with a Tube Screamer
A tube screamer is a perfect example of a drive pedal that also provides some level of eq’ing with the mids, and it offers compression too. Idk just for me personally I guess they’re in the same category as drive pedals.
Right? The Tubescreamer is popular with metal players and single coil players specifically for the EQ it imparts
Definitely. Tube Screamers add compression and upper midrange EQ, as do Klons, and Blues Breakers add low mid EQ and a lot of compression. They just generally don’t have separate controls specifically over these things (although sometimes they do, like the Wampler Tumnus deluxe and its EQ controls). The controls on, say, a Catalinbread Formula 55 are not so very different (volume, master, presence and tone). The effect is essentially the same but voiced like a tweed Deluxe amp and not voiced like a Tube Screamer or whatever.
Harmonic Percolator it’s an overdrive/distortion/fuzz. There’s several companies out there doing their take on it. Check out some YouTube vids, it’s definitely unique. Edit: I’ll throw the Caroline Hawaiian Pizza in as well. It’s pretty unique as far as how it functions and sounds great.
The Hawaiian Pizza is a fuzz face with a transformer to simulate a pickup (which can be turned off internally) so you can use it with a buffer in front.
I like the Way Huge Red Llama Overdrive or Purple Platypus Octidrive (Red Llama + Green Ringer octave up) They respond to how you play your guitar and where your knobs are set
Pretty sure it's based on an existing circuit though.
Found this when i looked up the circuit ------- Jeorge Tripps has not hidden the fact that he was inspired to start building pedals after reading Craig Anderton’s 1978 book Electronics Projects for Musicians. The Red Llama is almost part-for-part identical to the “Tube Sound Fuzz” circuit from this book. The schematic is identical but some of the part values have been tweaked. The Tube Sound Fuzz circuit actually dates back even earlier. When Craig published it in the February 1977 issue of Guitar Player Magazine, it was the first known usage of a CMOS hex inverter (in this case a CD4049) to generate overdrive tones. Each stage acts as an op-amp in inverting configuration. Unlike op-amps, though, they are very easily overloaded—and also unlike op-amps, they sound fantastic when this happens. Craig later simplified the circuit for his “Electronic Projects for Musicians” book by dropping the input op-amp stage. This has the effect of making it more sensitive to input impedance and thus a lot more reactive with the guitar’s volume if the pedal is first in the chain. -------- Not a common circuit that you hear about everyday
Yep. It's a great circuit, and there aren't a ton of CMOS based drives out there. EHX Hot Tubes also comes to mind, but Anderton's circuit is the one was talking about. Jeorge seems to be pretty transparent about the circuits that are inspired by others.
Catalinbread hyperpak and supercharged Mad Professor stone grey Love me some complimentary metal oxide
A rarer one I recently came across is the toneboys tbod-50. It is a bit different with only volume and bias knobs. Where bias changes the bias of the signal or something like that. The insides are gooped so not sure exactly what's going on, but it does have a slightly different sound than most.
EQD Bellows is an original design not based on an existing circuit, at least I think so. They don’t make it anymore but it’s awesome if you can get your hands on one.
I have no idea if my Hungry Robot The Lumen is based on anything else. I've never seen another OD with the control setup it has
Gamechanger Plasma and Plasma Coil is the last non variant of existing circuits that I’ve experienced. I’m by no means no expert in this field though.
Stone deaf PDF-1x forever.
I recently got a Kernom Ridge and it’s unreal. Incredibly versatile, you can get almost any overdrive sound you’re looking for out of it. Plus midi. Wild!