GizmoAudio – Sawmill Jr. and Ripsaw

By Scott Auld


A couple of weeks ago, GizmoAudio founder, owner, and lifelong musician Charles Luke sent us a couple of his pedals to check out. Charles said that he originally set out to design his own overdrive pedal that would give him the clean sound he couldn’t get out of other pedals, and after testing and honing and working, the Sawmill was born. He also sent us the RIPSAW high gain distortion pedal that he makes. I asked what the difference in the two is - Charles says the Sawmill design is Mosfet based, the Ripsaw is transistor based. He says they run off of different supply voltages but the main difference is the type of transistors used - he had to run the Mosfets at a higher voltage to get to the sweet spot.

Both pedals are constructed solidly in a powder-coated steel case and take standard guitar pedal power inputs. Their dimensions are: Width 2 ¾” x Length 4 ¾” x Height 2 3/8”, Weight: 14 oz. The switches were nice and quiet, no popping, and there was no unwanted hum or hiss from the pedals when they were turned on.

The GizmoAudio website brags that both pedals provide dynamic overdrive with touch-sensitive breakup and clarity. He's right. I found the distortion and overdrive both to be very musical in tone and not overbearing at all. If I had to make a comparison I would say they sit nicely somewhere in between the OCD and Zendrive families of overdrive sounds. The pedals sounded great both at low volume and high volume. Charles really was able to bring out the sense of touch in your playing. Both pedals really shine when you set them at the edge of breakup with a soft picking style. "Touch sensitive" has become a marketing term lately that often has no bearing on an actual pedal performance, but in the case of these two GizmoAudio pedals the ability to go from clean to overdrive, simply by changing how much you dig in with your pick, without having to touch a volume knob or another pedal, is a major benefit with pedals as touch-sensitive as this. In one sense this allows you to concentrate more on inspiration and less on knob-twiddling. The high headroom, the more gradual onset of distortion, and the clarity are all technical design attributes, but they really give the artist more freedom of expression.

Speaking of the design - it's very unusual for the USPTO to issue a patent for something like a guitar pedal design. The abundance of "prior art" makes it very difficult for builders to get a patent granted. The Sawmill Jr is, in fact, a patented design – in fact, it’s so rare, Charles showed me the patent when I asked about it. Charles told me his patent examiner was one tough cookie and he had to really work to explain why the Sawmill is an original patentable design.

The SAWMILL JR. is a true-bypass, medium-light overdrive that Charles designed to react like your tube amp. He wanted it to deliver extreme dynamics so he designed in an internal +/- 15V power supply which provides high headroom. Charles says the Sawmill Jr. is Mosfet based, containing both internal bias for the locating the Mosfet’s “Sweet Spot” and circuitry for cancelling non-musical intermods. Now, just between you and me, we've seen pedal builders use "intermod" as a buzzword to make the marketing sound impressive to people who don't build pedals. Usually, intermodulation distortion is not a real big concern in guitar pedal circuits. It's the kind of thing that hi-fi stereo designers worry about in expensive amplifiers for tube-preamp CD players and all that fancy stuff, or the kind of thing that crops up if you play multiple instruments through one amp/speaker. It's not usually a guitar pedal problem. But, Charles explained that when there are non-linear circuits both intermods and harmonics are created, even in guitar player scenarios. He explained that for a single tone passing through non-linear circuits, you only get harmonics, but when multiple tones enter the circuitry you get harmonics AND intermods. He explained that this is why some pedals will sound good on lead solos but if you play a complicated chord they mud up - this is caused by intermods. He explained that intermods are the sum and difference frequencies that are produced when two frequencies enter a distortion or non-linear circuit. He points out that some intermods are more "musical" than others - the intermods that are close in frequency to the two input tones are the most musical but an over abundance of these will cause a guitar player to have to use power chords instead of full chords. He says that the most unmusical intermods are those that come out near DC, typically producing a muddy farty sound with multiple input tones. Charles explains that what he's done is eliminate the intermods near DC without hurting the guitar's tone or other more musical intermods. Charles explains that that's how the pedals maintain the level of clarity they do.

This pedal is very clear through the entire range of overdrive, from near-clean to heavy. It responds well to my picking attack - and I'm a light picker.
The Sawmill has a Drive Control to set the level into the overdrive circuitry, a Tone Control that includes a Variable Lowpass filter that is located post-distortion, an unlabeled Bass Cut toggle switch (in the documentation it's called a Fat Switch, online it's a Bass Cut, either way you get the idea - which is a switchable highpass filter, pre-distortion. Charles recommends that this control be used to control the fullness of the bottom end of your tone, to reduce fullness when playing with a large band, or switched to keep the bottom in when playing with a smaller band where a fuller sound is needed. I found that it also helps the pedals work better with a wider range of guitars - it helps them get along with both humbuckers and single coils.

The RIPSAW pedal is a heavier-gain pedal with more edge, more bite, perhaps more aggressive. I would not call it a 'shredder' or 'doom-metal' pedal - it's just got more edge than the Sawmill Jr. It’s not a bunch of bumble bees in a tin can, either - with full on distortion the Ripsaw maintains clarity and you can still hear the individual sound of your different pickups and your guitar. It's the same size and weight as the Sawmill, and they really sound great TOGETHER. Stacking the pedals together gave a singing, soaring lead tone. The Ripsaw is the same size and weight as the Sawmill and has an identical control layout.

A quirk I found with both pedals was that the Volume Control does not shunt the signal all the way off if you turn it all the way down (when the pedal is engaged, obviously). I am used to pedals that can turn volume way, way down - but both of the pedals that Charles sent me don't really turn down all the way. When I had the Drive control up more than halfway, the lowest volume setting was still pretty loud. When I asked Charles why he went this way with his volume controls, he explained that his pedals are designed to work as an OD/distortion or clean boost. Certainly, he could have dialed back the gain for unity gain but he says it would have been difficult to get the required gain in both modes that way - clean with drive low and volume high or OD/distortion with drive high and volume low. He points out that in both these cases you still usually want to push the amp a little. His point: when you want a boost, you are not looking to turn DOWN the volume of your signal. I agree, but it was unusual.

Another quirk: the top-mounted input & output jacks (on both of the pedals) are laid out left-to-right instead of the standard right-to-left. This means that on my pedalboard, my patch cables had to go from the left side of a previous pedal, across to the top-left corner of the first GizmoAudio pedal, then out of the top-right corner of that pedal down across again to the right-side input of your next pedal in line. Even though all jacks were top-mounted (instead of side-mounted), I found that my shorter patch cables were too short to be used so I had to dig out some longer ones. If ALL of your pedals are top-mounted, you'll probably have no problem with standard patch cables, but if you are connecting a side-mounted jack to the top-mounted GizmoAudio pedal, be aware that you'll need a little longer patch cable than you usually do. And if you’re using super-short one-inch patch cables like the solderless kits we keep seeing, you’ll need an extra inch or so. Charles explained that he likes the signal to go from left to right, drive on left, volume on right, on his own pedal layouts. He says that on an early prototype he also had the input output like normal but found that internally, the input signal had to cross over the output signal, creating oscillation at the highest gain settings. Because of this he says he swapped the in/out. Again, since the connections are on the top and not the sides, it's less of an issue unless you are connecting other side-mounted pedals.

Charles is a one-man shop in Atlanta. He does all his own designs. He keeps the graphics design in the family and Charles says he has worked around the Atlanta area long enough to have a lot of friends in the area he can call on from time to time to assist when volume gets heavy. Charles sent me a photo of his workshop and it's your typical mad-scientist "looks cluttered but he knows where everything is" work area. He seems like a great guy, too – that matters to me when I’m shopping for a new pedal. Nothing is worse than looking down at your pedal board and seeing a pedal that reminds you of a bad experience. Charles has been great to work with over the past month.
I really enjoyed my time with both pedals and regret having to return them to him. If you're looking for a new pedal to get some nice overdrive or distortion sounds, want to buy from an American builder, and want to try out his patented Sawmill circuit, head on over to and check out what Charles has to offer. I don't think you're going to be disappointed.