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Two Iconic Overdrives in One Stompbox

Now with flexible signal routing: stack channels in either direction or use flip-flop mode to hop between channels with a single stomp.

The ultimate hybrid? Only you can be the judge.

The K818 is a dual overdrive preamp bred through and through with iconic Klon Centaur and Tube Screamer (OD820) inspired DNA. With a wide dynamic range, sweet overdrive, and lowered noise floor, the K818 is well suited to cover a variety of playing styles and genres; most notably blues-rock.

Never compromise your tone!

Notable Features

  • Klone on the right, Screamer on the left
  • Two independent channels
  • 30 volts of boosted dynamic headroom - preamp power!
  • Transparent buffered input/output
  • Flexible signal routing
  • Accepts standard 9VDC pedal power supply 

Designed and assembled in the USA.

Product Reviews

Score: 5 out of 5 (based on 27 ratings)
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K818 - Tone and Versatility
Written by Daniel C on Jun 23rd 2021

2-1 overdrives are hard for me to pass on. This one is no exception. These are two circuits which I tend to be particular about and the K818 does both very well. It covers all vintage / classic rock tones that I go for on my board. Build quality is excellent. Would highly recommend to anyone who enjoys either of these circuits or is looking for a classic rock sound all in one box. Well done, sir.

Written by Jeremy on Mar 27th 2021

Great sounding overdrive! Smooth bluesy tone. I dig it! Great customer service too!

Written by Fausto on Mar 14th 2021


Written by Michael Pratchard on Mar 7th 2021

I don’t use pedals a lot, but when I do.....I prefer Greenchild! Just got my K818 and put it through it’s paces. Outstanding tone. Melvin has hit it out of the park with this one. This is my third Greenchild pedal. I’m waiting on the MAGA pedal to reorganize my pedalboard. I might as well call it my Greenchild board!

Blues forever!
Written by Erik Montero on Feb 18th 2021

I bought this pedal specifically to marry with my new Fender Stratocaster American Professional II and I can't tell you how happy I am. This pedal further brought out the true classic blues tone from my new Stratocaster. The drive and gain are so clean and pure I can't get over it. I can't wait to see what else this company comes up with!

Written by Tim on Feb 7th 2021

Can't get a bad sound out of this pedal... I tried. With selectable stack order and flip-flop mode this could very well replace all my other "dual pedal" OD pedals

Versatile Tone Machine
Written by Stephen C. on Feb 6th 2021

I have been stacking ODs almost from the time I began playing an electric guitar and this has some of the best tone options I've found. The ability to change the direction of the signal flow with the flip of a switch is really unique! When playing the two types independently, you can get some of those classic 70's sounds... and when stacking them together it gets you into heavy blues rock territory! It works well with my all my other pedals and the compact design saves a lot of board space. For a single pedal that give you so many options in one small package, this is a great value for the price.

Greenchild K818
Written by Kory Neider on Jun 13th 2020

I love this pedal and am surprized at the quality of the Tube Screamer and Klon sides of the pedal. The specific mixture, texture, tone, endless overdrive and hybrid combinations, is exciting! I have played for over 50 years and am excessively OCD about tone. This is a high level product. Mason has been exceptional to work with and has treated me with respect, objectivity, and kindness. I have great respect for him and his craft! Thank you!

Written by Peter Johnston on Apr 19th 2020

The K818 has what it takes for that nice clean to dirty blues rock. Each side by itself does exactly what it's supposed to for those genre's they were designed for, but when you engage them both together you can span the whole spectrum and find whatever your looking for in one pedal. If your like me and you want to take it further, this pedal with a Mr. Boost in front goes Hard Rock quick and a new plethora of tone becomes available. This thing really rocks! Now one step further with a compressor and gate and this Baby goes into Metal Destruction! Everything I have added either before or after this pedal has become nothing short of pure aural pleasure no matter what you're into. If you haven't bought one then you're missing out!

K818 Pedal
Written by Mike Vitucci on Feb 14th 2020

Hey Mason I love your pedal. At practice last night it drove a 63 Princeton Reverb to it's best sound ever. I had to leave it with my guitar buddy for a few days. He begged me- What could I say? Thanks

Written by Robert Morris on Feb 1st 2020

This pedal is exactly what I was looking for . It tightened up my clean tone, and has that great “in between” tone too. Can wait to try it out live in a few weeks. Good stuff. Keep up the good work guys!!

Fantastic Overdrive Pedal
Written by Daniel Gerber on Aug 22nd 2019

I absolutely love the sounds that I have been able to create with my Greenchild K818 pedal. When I saw that the K-818 was sold out on the site, I asked if anymore would be made. I was told not in the foreseeable future, but I was referred to Gear Hero that had 1 available. It was a special edition in green. I am so glad I purchased the pedal. I feel somewhat special like I got the last new K-818 available, and it's even a special color. The sound is so crisp and clear. The Tube screamer tone is way smoother than my Ibanez TS-9. This pedal really stacks well with my EHX Crayon too. I can't wait to get more experience with it. Great job Mason!!! I hope you decide to make more K-818s so other players will be able to enjoy them too!!

Excellent pedal for excellent tone!
Written by Bob Salitsky on Aug 23rd 2018

The K818 is a fantastic pedal that takes two classic overdrive circuits and makes them even better. The noise floor is extremely low which is great for stacking the K818's two stages with each other as well as with other OD pedals. There is a ton of great tonal range possible with this pedal. The build quality is top notch and the footprint is nice considering it's really two pedals in one. Additionally Mason's personal attention to detail makes for a great customer experience.

Written by ERIC SCOTT on Aug 6th 2018

Mason just wanted to take a minute and say thanks for a great product . Had a chance to spend a couple hours with my K818. Running into a Deluxe Reverb it was absolutely everything I expected and nothing less . The Klon Circuit is dead on . The Tube Screamer circuit I think is actually better than the Ibanez 808DX I have been using . Two great pedals in one.

Great pedal, Great company
Written by Dave Shireman on Jun 7th 2018

No matter what style of music you play, you're going to find so many usable settings with this pedal. This is brilliant, and will give you a truly unique sound that will stand out from everyone else. As for this company, he will go above and beyond to make sure customers are taken care of and I couldn't be happier. Thank you guys!

Written by David Story on Apr 27th 2018

I love this pedal! It's like a Klon and a Tube Screamer in one pedal. I like being able to get nice controlled feedback with sustain and this pedal is silky smooth in that aspect. You can use it as a clean boost as well. It's very versatile and I like to play stuff like ZZ Top to Judas Priest. Buy it, you won't regret it. And, the designer/owner is a former U.S. Navy man just like me! It rocks.

My choice drive to stack
Written by Lorin Chak on Mar 27th 2018

Hi Mason, just wanted to drop a line saying why I love my K818: its on my tiny board because of the screamer and the klon are the two drives I want as boost or 2nd/3rd gain stages, all in a small box, clickless switches (thank you!), and 30v headroom?? My ears may not hear that added clarity but I know this is one irreplaceable pedal for me. Thanks!!

King of Tone!
Written by Michael McKenzie on Mar 27th 2018

The K818 delivers just the tone I was looking for, particularly when running from an 18 volt supply. It is truly exceptional and is everything I hoped it would be and it is now a mainstay on my board. I used to have several different boutique drives but I've since sold most of them on as the K818 not only does the same job, most importantly, it does it better. I heard about the pedal on the Intheblues youtube channel originally but wasn't sure about ordering something from the US to the UK but the shipping price and process was straight forward and the pedal arrived within a few days. You get a truly personal service from Mason who runs the company too. The pedal was showing as out of stock and I emailed to see when it might be available and Mason got one built for me within 24 hours. I really wouldn't think twice about recommending this pedal and the company to anyone.

Fantastic Effect Box!
Written by Victor L. on Oct 2nd 2017

Great experience buying from Greenchild!

Will I ever need another overdrive?
Written by Liam Milross on Sep 21st 2017

The simple answer is no...

Great pedal!!!
Written by Dave M. on Jul 26th 2017

I've tried several of the new TS pedals, but never really got on with them. This one though is really nice, and combines wonderfully with the Klon. One thing though, watch your power supply. I had it ganged with another pedal, and together the draw must have been too high and it was REALLY noisy. Once I gave it a separate plug (from the same power supply), it was quiet again.

This is the one !!!
Written by Richard boyer on Jul 12th 2017

Words cannot accurately describe how much this pedal kicks ass. I heard it live when I saw Hall & Oates in Washington DC. I had to have one, it sounded that good. After I received it and tweaked very little, I was in tone heaven. This pedal will never leave my board.

Tone for Days!
Written by Oliver C. on May 20th 2017

The K818 is an outstanding tone monster! This pedal replaced my AC booster running into a Green Rhino! Into a 65 Deluxe Reverb, I really cut through the mix! Thanks Mason Oliver

Written by Pete W. on May 8th 2017

Now that the title is out of the way. I have been searching for particular tones. A slightly over driven Vox sound, and a Live at Leeds kind of sound, but I didn't want a bunch of pedals to do it. I also can not play at those volumes. Fortunately, I found the K818. Gets pretty close, even if that was not the pedals original intention. (Versatility at it's best.) It can get you blues tones. It can get you British invasion tones. It can get that loud stack tones. Why buy three pedals, when you can get it in one

He loves it!
Written by PATRICIA C. on Mar 31st 2017

I bought the K818 for my son, Eric Hutchins, for his birthday. He's loving it.

K818 Dual Channel Overdrive
Written by Richard Reid on Feb 12th 2017

a Klon Centaur designed circuit on one channel and a Screamer circuit on the other and both are outstanding in their capabilities to dial in diverse and rich fatty full of headroom brown and clipped light to medium over drive sound scapes...full of character that still punch out whatever model of guitar and pickups you use and their tone tone and sound character...and both circuits work incredible together stacked or stacked with other drives..the Screamer circuit I like so well that I am actually dumping a 90's TS( Analogman modded out unit and selling ti as I like and feel the warmth of the K818 Screamer circuit was far superior even thoguh the TS9 has an actual TI JRC4558D chip in it...the K818 Screamer circuit was way better to my ears palette an d taste and I can stack the K88 with a Lovepedal Amp Eleven OD/Clean Boost or Lovepedal SRV Super Six to dial in even more bodacious guitar player's goose bump big grins in fat brown tones..and when I used my 1057 lap Slide with the K818, Wooo!, I dialed in everything from sweet fat Dwayne Allman tone characters to Warren Haynes Gov'tMule face melt burn...and you Humbucker and les paul players, your Humbucker players/users will love this drive as well!

K818 (Retro)
Written by Jay D. on Jan 2nd 2017

I really like the pedal. It has great tone and is very versatile. It's very well built. When the manuals are printed will you mail me a copy A friend of mine really likes the K818 and the Tribus pedal. Are you planning on making more of them