VSS-30 Tutorial

The video above is of my most recent bent VSS-30 that uses a 12 point switch bay using 2 way center off switches. This is my documentation on bending a Yamaha VSS-30. This ultra sampling keyboard has some really awesome capabilities on it’s own. I got this info initially from one of the bending forums, but I don’t know who to credit, so thanks whoever you are! I know some folks haven’t bent their VSS yet due to fear of frying, so hopefully this guide will help you.

*Note*When I first did this bend, I avoided the 2 red dots (power and ground). I’ve since bent another VSS-30 and used these points with no ill effect. As always, bend at your own risk */note* The blue dots in 2 rows are the points of the sampling chip. The blue dots in a straight line going up and down is where the points connect to the big chip. There are 2 pins on the sampling chip that connect to each other (yellow line), so that gives you 15 points to bend. I chose to use 12 of those points for symmetry, and I chose to use an RCA style patchbay. I found that Tablebeast did a layout on one of these that I really liked, so I did this one the same way. You can see/hear his Here. I chose to solder to the points that were up and down in a straight line for ease of bundling.

Here’s the board wired up.

Here’s the area where I chose to put the RCA connectors. I checked, double checked my measurements. The pencil lines you see are where there’s a plastic support on the inside of the case.

Here’s the installed RCA jacks. Not absolutely perfect (need a drill press for that), but lookin’ pretty good IMHO.

Here’s the front side of the sample crusher for those that don’t have one already (keep an eye out cause if you don’t have one you’ll want one!).

Now let’s test it. Record a sample, and play it to make sure it recorded decently. Now plug in a patch cable to two of the RCA jacks. You should get all manners of distortions, tremolos, and all kinds of other effects on the sample. Layer the bends on top of each other with more patch cables, and you can completely change the sample so that it sounds nothing like it originally did. I used the loop feature built into the VSS to make some really awesome loops with the bent samples.

There’s an audio sample of this on my sample page.


As always I take no responsibility if you happen to touch the wrong point on your VSS, and kill it. I found this bend to be very reliable, and not to difficult to do if you take your time.

PSS-270, 170, 140 and SHS-10 Tutorial

After some major diggin’ for info I found that no one had a specific guide for bending a Yamaha PSS-270, so I decided to make one. Credit to Sean “audioid” (myspace.com/audioidbentaudio), and Paul from circuitbenders.co.uk for the info on this bend. This bend involves cutting data lines that go from the FM synth chip (YM2413) to the main chip (XC194A0). The pins on the FM chip that go to the main chip are pins 2, 3, 4, 5, 6, 7, 17, and 18. You cut the traces, and then solder wires on either side of the cut. Take the pair of wires from one cut, and solder them to a switch, and this will allow you to turn the flow of data on and off.

This is a picture of the board flipped over. I have the FM chip out-lined in red, and you can see the big chip under it.







In this picture I have the solder points from the FM chip marked in red dots, and the blue dots are where they go to the main chip. Ignore the green dots. The black line is where you *carefully* cut the data lines. I used a volt meter to check and make sure that the lines no longer had continuity.






I’ve indicated the FM chip in this picture.








Here’s all 16 wires in place. Some people recommend drilling very small holes on both sides of the trace cuts, and putting wires through them, or scraping the coating off so you can solder on it. I just soldered the wires onto the pins of the chip, which can be dangerous because you run the risk of overheating it. I used a pair of wires that are the same color for each connection to make wiring up the switches easier.





I’ve got the board back in place, and the wires bundled up nice and securely.







Now all the switches are wired up, and we are ready to button her back up.







I found the most room for the 8 switches on the right side of the keyboard. Just measure and drill carefully, and it will come out looking great.






What the Bends do:

Each switch now controls the flow of data from the FM chip to the main chip. Turn the PSS on and select a patch (let’s pull up #89 “ghost”), I usually play some keys(don’t know if you have to do this or not), then turn some switches off , now select a different patch, and turn the switches back on. Now try playing the new patch. If it went well some of the data from the all patch got held up, and then inserted into the new patch making a totally different sound. Sometimes leaving the connections off will change the sounds also. I’ve noticed them some of the bent up patches will only work when multiple keys are played. I’ve heard that this will effect the drums as well, but I haven’t gotten it to do much with them as of yet.

Getting some good sounds out of this takes some tinkering, but it’s worth it. The only downer is that it’s hard to reproduce the sounds that you get, so if you have a good one be sure to grab a sample while you can. Using the keyboard this way can corrupt the data to the point where the chip crashes in a noisy mess, but all you have to do is turn all the data connections back on, and turn the keyboard off, then back on. All the data connection switches have to be on for the keyboard to work “normally”.

John from Bentpedals sent me these photos of a PSS-140 that he did up using this same mod. The main chip is colored in red, the FM chip in blue, ignore the yellow.






I did the mod on a PSS-140 for Mjm using the info that John gave me. This is what he had to say about it “endless amounts of fun. endless unpredictable possibilities. i don’t want to stop messing with it”. Here’s some photos of that.

Wesley did the same mod to a PSS-170, but his link seems to be dead.


 I’ve successfully done this on a Yamaha SHS-10 Keytar , along with some other circuit bends. Tinsoldier sent me a diagram of his circuit bent SHS-10 which I will post here. I can’t comment on it at yet because I haven’t had the chance to try them myself.








As always I won’t be held responsible if you try this bend and your Yamaha get’s hurt. I’ve done a lot of playing with this keyboard, and it seems real solid to me. This bend works on some of the other PSS series keyboards (like the 140) with a similar chip setup, but since I’ve only done a 270 and 140 so far I can’t gurantee it will work on all of them.

Furby Bending Tutorial

Since I’ve been asked many times about bending furbies I thought I would make this guide to help those that would like to give it a try.

This furby is in the typical shape I find most of them in. Let’s take away his dignity further by striping him of his fur.

This lump on his bottom side is where there is a strap tie holding his fur on. Cut this, and pull the tie strap out.
Furby 3
Roll his ears back and cut the threads holding them on.

I usually roll his fur up along his body so we can expose the screws holding his face piece on. Remove the screws, and there will be some hot melt glue attaching the fur to the top of his head. With some light tugging the fur should free and then you’ll have your very own naked furby. Remove all the screws from the carapace, and it will come apart in 2 halves.

See, look at how liberated he is to be freed of that cumbersome fur.
Furby 6
You have to take off the speaker/tummy switch to be able to tilt his battery compartment over, and get to the circuit board underneath. This is also a good time to add wires to the speaker for your output jack.
Furby 8

I’ve found a stable glitch, and loop bend that stem from the same common point. I have the common marked in red, the glitch in blue, and the loop in green. Your mileage may vary from one furby to the next. On this particular furby I used a 47 ohm resistor in line with the glitch wire to make it a little more stable. I’m sure that there are more bends in a furby, but I haven’t dug to deep because I’ve heard that these fry easy.

The bending has changed him some how….

I normally run the bend wires along the right side of the furby up to his head. There is a small area on the back of a furbie’s head where you can drill a hole, and run the wires out to a control box. I normally set it up with a switch for the glitch bend, a normally open push button, and switch for the loop. You use the push button to find a loop you like, and then flip the switch to lock it in.

I’ve had a lot of people ask me about the way the loop section is wired, so I made up a nitty gritty diagram in MS paint. I still have the wires colored the same as in the circuit board diagram. Basically what’s happening is that you have the same connection wired to 2 different kinds of switches.


As always I won’t be held responsible if you try this bend and your Furby get’s hurt!

I’ve done quite a few furbies now, and I always try to make each one unique to the others. I’ve played around with decorating them in strange ways, and I built one that has all it’s bends controlled by an Atari style joystick. I’m going to post some pics of a few of these on this page.

Circuit Bent Samples/Sample Albums

I’ve recently setup my Soundclick page with the ability for people to download the samples of .75 a piece, or as an album for 7.99. I’ve setup two albums, one is a collection of Vocal Glitches (like the Speak and Spells and furbys), and one is a collection of instruments that generate random music, beats, and sounds (like the Casio SA series, and the Musini). Here’s a link to the Store.


Over the past few years I’ve built a wide variety of instruments. Some are toys/keyboards/whatever that I re-purposed through circuit bending and modification, some are oscillator based instruments that I built from scratch, and more and more I’ve been dabbling in make effects pedals. I’ve built more things then I could ever possibly list here, but I will try and cover some of the more interesting things. If you want a better idea of what all I’ve done you can got to my Soundclick page. I also have a Youtube Page where you can “see” my instruments in action.

I have two effects pedals that I regularly build. One is the “Mutator” which is a heavily modified toy voice changer re-purposed for guitar/whatever. See those here. The other is a modified Fab Echo. I take this rather tame Echo pedal, and modify it into a fully function delay with lots of features. See those here. I’ve also tried my hand at making more traditional pedals, which you can see here.

I’ve modified lots of keyboards, mostly lower end Casios and Yamahas, but also some toy keyboards as well. The mods have been anywhere from a simple pitch control or glitch push button, all the way to an out board RCA patch (Modular Synth Style) with hundreds of possibilites.

Casio SK-1
One of the holy grails of bending. Most benders want one, have done one, or have done many. The first few a did were based on the “Tablebeast” mods (16 point patch bay with on/off switches). Now that I have some experience with them I’ve undertaken some more complex mods.

This is the first SK-1 I’ve modified. It has the “Tablebeast” Patch bay setup with Pitch Knob, Drum Kill, and Poly Kill Switches. This SK-1 is sold

This SK-1 has pretty much the same mods as the above one, but with the addition of body contacts. This SK-1 is sold.

This just the patchbay for my “Glitchstation” SK-1. The keyboard itself only had a 25 pin connector, pitch knob+body contact, drum kill switch, and 1/4 inch output. The patchbay itself contained all the controls. Housed in an old PS2 case (hence the name) it contained a 26 point patchbay (2 points to ground), 8 point switching patchbay, 3 knobs of different values, and sample and hold section, 3 momentary joystics, and an LFO that can be patched with everything else. This project was complicated and difficult, I don’t know if I would ever take it on again. This keyboard/monster has been sold.

Yamaha VSS-30

By far one of my favorite bends. This sampling keyboard does great on it’s own, but with the addition of some bends becomes a sample crushing machine. See my tutorial for pics, and of course how to make your own. If you have one you would like me to modify just send me a line through the contact page

Modified Fab Echo

Modded Fab Echo


On a whim I bought one of these little boxes. For less then 20 bucks I figured what the heck! Did a little searching on Aron’s DIY Stompbox Forum, and found out that the Fab Echo uses a common chip to full on delay pedals. After checking over a couple schematics I (with the help of some forum members) found out how to un-lock the Fab Echo’s delay potential. I have the ability to add a Delay “Rate” knob (speed of repeats), increase the mix knob to full wetness, and to give it full feedback (which literally makes it feedback). On top of these controls I’ve also added LFO’s to the delay circuit that cause strange swirly sounds, and pitch bending weirdness. I mount the Fab Echo on to a larger box (in most cases) to make room for the added controls (there is no room inside these things. I set the LFO up to be powered by the 9v battery, or a pedal power supply. I’ve been charging 140. for the full setup (with LFO), and would of course charge less for a simplier one.
If you are interested in getting a Modified Fab Echo please send me a line through my contact page

For those that want to take on the basic mods themselves here is a link from the DIYstompboxes forum to the best documention of it I’ve found thus far.

Fab Echo

This is the first modified Danelectro “Fab Echo” pedal that I built. I made it so that that it now has a controllable delay time (from short to very long), and also made it so that you can control the delay time with the large knob or light senor. I also made it so that the pedal can feedback when the repeat knob is turned all the way up. There’s an added jack for expression pedal control of the delay time. This one has been sold.

Fab Echo

This is the second Fab Echo that I’ve modified. This one has the LFO feature built into it with with rate indicating LED, Rate control knob, and LFO on/off besides the usual mods. I will definitely take custom orders for these now that I have a good method for modifying them. This Fab Echo has sold.

Fab Echo

This version has all the mods above, plus the Osc. can go between triangle and squarewaves. This Fab Echo has been sold.

Fab Echo

This Fab Echo has all the earlier mentioned mods, plus it has some modifications to the LFO circuit. This one has the ability to have square or triangle shaped waves controlled by a pot to get the in-betweens, and there is a Depth knob that really opens up the versatility of the LFO feature. This Fab Echo has been sold.



Mutators are a series of effects pedals I’ve been working on for a little while. A Mutator is, at it’s core, the circuit from a toy voice changer used as an effects pedal. I’m not the first one to do this by a long shot, but I build them more like real guitar pedals, which I haven’t seen anyone else doing so far.

One thing I want to say right now before I go any further is that these pedals are NOISY. They are not high quality/expensive pitch shifters, or ring mods with no carrier bleed. They pretty much destroy the tone of anything you run through them (in a good way IMHO). Also, when you aren’t playing with the effect on you will get the “background noise” (barely audible hissing, and osc bleed through) from the circuit. These circuits also have a built in gate, so when you play a note the pedal while shut it off when it decays to a certain point (cuts the sustain of the note). I’ve tried putting a booster in the front end of the pedal to help with this, but you could just run a distortion in front of it for the same effect.

Mutator features/options
Mutators in most cases get re-housed into a stronger (metal) housing. I add quality 1/4 inch input and output jacks, and a true bypass stomp switch with indicating LED. They almost always run on a 9v battery, and get a new, better 9v connector. I replace the sound selection switch with a new stronger switch to go between the sounds on the voice changer (usually “Spaceman, Ghost, Alien, Robot”, etc) There are usually 3 different sounds to choose from, so there is a three position switch on the Mutator. I’ve been able to do this with toggles, and rotary switches, so let me know if you have a preference. Next I add a knob that controls the “pitch” of the sounds. These things sound pretty wild just running something through them un-modified, but playing with this knob, and you get some really unusual sounds. This pretty much covers the “Basic” Mutator setup. Average price for one with these controls is about 80.00 dollars.

If the “basics” isn’t enough knobs for your knob twiddling pleasure I’ve come up with several more mods to these pedals.

The first one is the easiest, a Volume knob. Simple, but useful. If that’s the only option you want on a “basic” then ask me nice, and I’ll likely put it on for free.

Next is a Gain knob or switch (depends on the circuit). It cranks up the volume and adds more distortion to the sounds. Quite brutal!

Third is an Oscillation effect. This adds a sqaurewave osc to the sound of the pedal that has controllable pitch with a knob, and an on/off switch for the effect. Very thick and synthy, but of course adds to the overall noise of the pedal.

Fourth is a Feedback control. Much like a Feedback Loop pedal I feed the output of the pedal back into it’s input through a knob, and a on/off switch. Modulations galore!

Another feature I’ve added is a Starve feature. This literal turns down the amount of power that the internal audio chips are getting. It does pretty much what you would expect it to do, noisy degradation of the audio with major gating. Controlled with an on/off switch, and knob.

On several pedals like this I’ve added the ability to control an effect with a light dependant resistor. What the LDR does is change the pitch when something shadows the amount of light going to it (be it your hand, or toe of your shoe). The more light it sees the higher the pitch, the less it sees the lower the pitch (generally, but there are exceptions). Controls are a switch and LDR.

These controls will run at about 120 to 140 depending. These are also very dependant on how the circuit behaves, one mod might work, while another doesn’t. Another thing to add to this part is stomp switches. I can setup any of these features to be activated with a stomp switch+indicating LED so you don’t have to bend down while playing to turn it on. This of course adds to the cost because stomp switches are pricey.

Added Circuity
Now we get to some more advanced stuff where I actually add circuitry to the pedal. As stated above I have put booster in front of the circuit to boost the signal above the gate for a longer sustain. This could have a gain control on it, or could just be set at a static amount of gain.

Next is the addition of an LFO to modulate the pitch. This will effect the sound of the pedal everytime the LFO cycles giving it a rhytmic pitch shifting character not unlike some of the old modular synths. Controls are an on/off switch, rate knob, and (sometimes, depends on the circuit) rate indicating LED.

I have a few more ideas for this that I haven’t tried yet. One is a triangle shaped LFO to cause swelling up and down pitch changers similar to a phaser. The other is an envelope tracking circuit that will change the pitch with the strength of the guitar/whatever’s signal.
These mods run 140 and up depending on what else you would like to have.

Here’s some of the Mutators that I’ve already built. All are already sold unless otherwise indicated. Scroll down to the bottom for the most current builds.

First Mutator

This is the first mutator I built. I decided to leave it in the megaphone housing because I had room for the input, and output jacks. Both of the jacks muted the speaker, and microphone respectively. I also added a switch that would lock the trigger switch in the “on” position. I added a course, and fine mutation control, and body contacts that modulated the effect. This Mutator has been sold.

The second mutator I built I housed in an old Radio Shack computer toy. I set this up to be a “table top” effect for the Noise crowd. When looking at the circuit I noticed that it had an LM386 in it for amplification. I knew that was a common chip for guitar effects, so I used some of the tricks I learned from Colin of Experimentalists Anonymous. Colin has a pedal he builds based off of the LM386 called the Parallel Universe that has a gain and osc. feature. Based off of Colin’s schematics I was able to add these effects to this Mutator. The controls on this Mutator were On/Off switch, True Bypass switch, 3 way Mutation selection switch, Osc. on/off switch, Volume knob, Gain knob, Mutation knob, Osc. Freq. knob. This Mutator has been sold.

The 3rd Mutator I built was the first that was setup like a guitar effect box. I housed it in a the box for a piece of test equipment (the box is HUGE). I set it up with a true bypass stomp switch, 3 way switch to select the different sounds,gain, mutation, and osc. frequency knobs, and a stomp switch to turn the osc on/off. There are bright orange LEDs inside the box for the bypass, and osc switches that shine out the sides. This Mutator has been sold.


This is the 4th Mutator I’ve built. I housed it in an old box marked “High Voltage” (pretty cool!). This one has a true bypass stomp switch, volume, gain, mutate, and strave knobs, 5 switches to select different sounds, and a stomp switch to turn the strave feature on/off. There are 2 bright orange LEDs that indicate bypass, and starve on/off. This Mutator has been sold.

This is the 5th Mutator I’ve built. This one is housed in the control box for an old fog machine. This one has a true bypass stomp switch, gain, mutation, and feedback knobs, an on/off for the feedback, and a rotary switch that selects the different sounds. The red, white, and blue lights on top indicate bypass state, and the orange light indicate feedback on/off. This Mutator has been sold.


I built this Mutator for Opsysbug. It has the usual Mutator controls, plus an LFO feature that stutters the mutation in a rhythmic pattern. The LFO has a rate knob and on/off switch. This Mutator has been sold.


A throw back to the first mutator. This one has the the mutate knob, body contacts that have the same effect as the mutate knob mounted in the handle, feedback switch, gain switch, trigger lock switch (keeps it on), and switching 1/4” input and output jacks. Click on the picture for a sound sample. This mutator is sold.

This Mutator is similar to the IV. It has mutilple switches to select the different sounds, Gain/volume knob, and Course and fine mutation controls. It’s mounted in an old relay box of some sort. This Mutator has been sold.

Housed in one of the cooler enclosures I’ve ever recycled, this mutator has a Volume knob, Mutation switch and pitch knob, and a feedback knob. It has a true bypass stomp switch, bright blue LED, and runs on a 9V battery. It is currently for sale for 100.00 plus shipping. This pedal has sold.

Clean Up Complete

I’m all done straightening up pages. Probably have a few links to fix as I find them.

Hoping to add some new content once I get some photos and such uploaded. Stay tuned! Same Bent Time, Same Bent Channel.

Pardon our Solder Smoke

 This site has needed straightened up for quite sometime, and I’m a little more then half way done. Working on slimming it down to make room for new content and projects.

  You can navigate to different pages through the side bar as always, and I’m working on setting up better links in the pages that follow. Hope to have it all done by this weekend.