All posts by Austin

Modified Jaymar Toy Piano

by Austin Cliffe/ Creme DeMentia

Jaymar Toy Piano with Piezo Pickup and Removable Back by Austin Cliffe

Like many of you who are reading this, I spend a lot of time in thrift stores.  I have come across some older toy pianos in my thrift store adventures.  Toy pianos are actually pretty serious and widely used musical instruments.  They have a very distinct sound and you’ll be surprised how often you will hear them used once you recognize their timbre.  They are also somewhat valuable and sought after instruments, believe it or not.

When I bought these toy pianos, it was with the intent to install a piezo-electric pickup in them and resell them, since I had so many discs for making Bottle-Cap Contact Microphones.  I was intrigued to see that Nick Heimer, who I had met at Bent Fest Minneapolis 2007, had a similar idea and brought the resulting devices with him to Circuitastrophe;  his toy pianos were not only equipped with piezo pickups, but also had bent delay circuits bolted to them that would process the sounds coming from the pickup.  They are very bizarre-sounding, beautiful instruments.

Toy Piano with Circuit Bent Delay by Nick Heimer

Adding the pickup and output to my toy piano was relatively easy.  I found a good spot on the backboard to attach the pickup using a stethoscope, then glued the piezo disc in place with epoxy, finally covering it with a protective layer of Plasti-Dip.  The piezo pickup runs directly to a 1/4″ mono jack, which I recessed into the back panel.

Jaymar Toy Piano with Piezo Pickup and Removable Back by Austin Cliffe

Jaymar Toy Piano with Piezo Pickup and Removable Back by Austin Cliffe

Initially the Toy Piano didn’t play quite right, I had to diagnose the problem after taking it apart.  Toy pianos work similarly to regular pianos; instead of the hammers hitting strings, though, they hit corresponding tuned tines.  The comb of tines is mounted directly to the back panel.  The problem with my toy piano was that the back panel was installed crooked at the factory and not all the hammers were hitting their corresponding tines. I pulled out the factory-installed staples, fixed the alignment, and screwed the panel back on correctly.  In fixing the alignment of the back panel, I had the idea to make it removable so that you could play the tines however you like when the panel was removed.  I achieved this with hanger bolts and wing nut accompanied by a handle.

The idea of playing the insides of a piano is nothing new, and this project reminded me of two avant-garde composers of the 20th century, John Cage and Henry Cowell.

John Cage is probably a name you know;  did you know he composed pieces for toy piano?  He also composed a piece called “Cartridge Music,” where the performers would use phonograph cartridges to amplify objects.  Piezo-electric discs are now often substituted for phonograph cartridges in performances of this piece;  Cage’s score provides specific times for when the different objects are to be played, but the choice of objects is left open to the performers.

Henry Cowell you might not know.  Henry Cowell developed a variety of experimental piano playing techniques in the early 1900s, one of which called for leaning inside the piano and manipulating the strings with bare hands to produce scrapes, howls and deep rumbles.  He employs this technique in a piece called The Banshee.  John Cage, like many other musicians, was inspired and influenced by Henry Cowell.  Cage also experimented with the insides of the piano, by putting bolts, eraser bits and other things in between the piano’s strings.  These inserted objects drastically changed the piano’s timbre and a normal piano could be prepared in this way by following his specific written instructions. Cage then wrote pieces for this new range of gamelan-like sounds coming from piano he had prepared.  This process can be undone and causes no harm to the piano.

For your enjoyment, here are some videos of myself and some friends exploring the sound capabilities of this device paired with some effects pedals.  The first video shows the piano being played normally, the second video shows the removable back being played.  As was my initial intent, this instrument will be for sale on eBay shortly after this article has been posted, simply search “GetLoFi Toy Piano.”



Creme DeMentia Bottle-Cap Contact Microphones Batch #3

Creme DeMentia Bottle-Cap Contact Mics Batch #3

by Austin

So, I have just finished Batch #3 of Creme DeMentia Bottle-Cap Contact Microphones. Since winter, I have been going out once a week or more on recycling days and gathering caps from people’s recycling bins. My friends collect caps for me and I have found myself drinking beers and sodas more on the merit of their caps than their flavor. I have sampled numerous regional and obscure sodas and beers to find new and interesting raw materials. My cap collection has become quite large and varied; as a result, I have become a little more playful with my designs this time around. You’ll notice a number of one-of-a-kind and non-uniform designs.

Here are the new designs:

If you place an order soon, you’ll receive one of the above varieties. Prices include First Class shipping to ANYWHERE IN THE WORLD. I have shipped to all over Europe, Canada, and the United States. There are no additional shipping charges to calculate, $15 for one, $65 for 6, plain and simple. Order now at

I’m going to take some of the more special microphones and auction them through eBay, starting with this design:

Black Knight Contact Microphone

Currently up for auction on eBay.

I recently attended an event in Rockford, IL, at a store called Just Goods. The event was called the Handmade Musical Instrument Exhibition and it brought together a number of local artists who make their own musical instruments. I attended thinking that I might meet some local, interesting, like-minded individuals and possibly sell some contact microphones; I was correct on both counts. I first met Paul Bourgeouis and Evan Clayburg, who both had made electronic instruments. Paul’s instruments were different variations on 555 and Hex Schmidt Trigger Oscillator Circuits. They made some very beautiful noises. Evan had assembled his instrument from an online sequencing kit and he had a CdS cell controller mounted in a rubber octopus hooked to the bare circuit board.

I also met David Stocker and Jim Worland, who were the main forces behind organizing the event. Jim Worland is a luthier who builds fantastic custom acoustic and electric guitars, some with added harp strings. David makes drums, ocarinas and other instruments from found and bought materials; he is an Illinois Artist in Residence and teaches workshops on building these instruments.

Canjo by David Stocker (

I traded David a couple of contact microphones for a device he makes that he calls a Canjo. The Canjo is your standard soup can screwed to a rigid stick. A guitar string is strung through a hole in the bottom of the can at one end of the stick and the string is bolted at the other end of the stick. By strumming the string and manipulating the can, you can produce some nice, springy melodies. When I got together with Alex and Patrick recently, we spent an evening playing the Canjo through one of my contact microphones and a Getlofi Fuzz Pedal; it sounded great!

I recently saw Pixar’s Wall-E for the first time. Though I enjoyed the movie, probably the most rewarding viewing experience on the DVD was in the Bonus Features – Animation Sound Design: Building Worlds From The Sound Up. This short documentary explores some of the techniques that legendary sound designer Ben Burtt (Star Wars) has used to create sound. It explores not only his harvesting of sounds, such as striking contact-mic’ed Slinkies and high tension wires to get laser-like sounds, but also his manipulation of sounds through unique software interfaces. The following video explores some of the same material, but the actual bonus feature on the DVD is much more thorough.


Particularly interesting to me in this documentary were the sound contraptions designed by Jimmy MacDonald for Disney in the 1930’s, 1940’s and 1950’s (which is not in the Youtube video). Disney studios first used musical instruments to produce sound effects, such as cymbal crashes for impact sounds and flute whooshes for cartoon characters flying through the air. This was because recording equipment of that age was too bulky to be portable and editing was laborious. Instead, artists would gather with their instruments and match their performances live to on-screen images in a large studio, where the recording equipment resided, reducing the need for editing. This method of scoring cartoons led to the creation of these noise instruments that could be controlled by a person or persons in the studio to create live sound effects performances, such as draw bridge chains rattling, bees buzzing, cartoon engines sputtering to life, rain, thunder, wind, and voices of mechanical-type characters. This documentary has a lot of archival footage of these devices and techniques being demonstrated and it makes for fascinating watching. Some of these devices are still stored and used at Disney Studios today and Ben Burtt used some of these devices in creating the sound universe of Wall-E. Definitely inspiring viewing for anyone who is thinking about making some of their own experimental acoustic instruments, perhaps to use with their very own Creme DeMentia Bottle-Cap Contact Microphones.

Inside The Leap Frog Alphabet Pal

Beaked Fuckapede 2.0

by Austin

For better or for worse, it seems that many people’s favorite toy that I have circuit bent is the Leap Frog Alphabet Pal, aka the Fuckapede.  It is the the only toy that I have bent that has seemed to spark enough interest in other people for them to decide to write about it and it is almost always the favorite of people newly introduced to circuit bending.  This toy, despite being one of my less musical bent devices, seems to strike a chord with people. I think the cute and unique design of the toy itself, the demented make-over I gave it, and its simple bend interface, not to mention its penchant for generating curses, appeal to the lay-person and benders alike.

Here’s the original Fuckapede in action:


To hear the swearing, go to 1:48

Leap Frog Alphabet Pal, Unmolested

This foul-mouthed toy created quite a stir when it was first released by Leap Frog in 1999. Though the toys were never officially recalled, as I understand, many angry parents returned these toys. When I first found a working Alphabet Pal in a thrift store, I was immediately drawn to its unique design; I had never seen a toy put together in segments like the ‘Pal and the individual feet buttons intrigued me.  It’s also disgustingly cute. I noticed the toy had three modes, Letter Names, Letter Sounds, and Colors. I began playing immediately in the Letter Sounds mode, as I thought those would probably be the toy’s most interesting sounds. Pressing A makes a short “A” sound, as in cat, B makes “Buh,” C “Kuh,” D “Duh,” E “Eh,” and F “Fuh,” etc. I then, like countless children across America, pressed F and C in succession to make it say “Fuh-K.” To my surprise, it actually said what sounded pretty close to “Fuck.” I knew then and there that I had to bend this toy. Little did I know, however, that this would be one of the more frustrating bending projects I would face nor that this toy had apparently infuriated enough uptight parents to be re-engineered several times since its initial release.

While researching the ‘Pal’s F-word fiasco, I noticed that there seems to be some confusion about this toy’s swearing. A lot of people’s online comments seem to indicate that they think the toy has some sort of filthy Easter egg phrase that some crafty toy designer programmed so that it says “Fuck” when you hold down some odd combination of keys. Others think that later versions of the toy says “Fuck You” when “F” then “J” are pressed.  There seems to be a lot of uncertain response videos on Youtube. The actual case is simply that a surprising amount of cuss words can be formed with the toy’s Letter Sounds function, provided you have the uncensored version of the toy; I sat down with my cousins one day and we figured out as many different dirty words as we could make it say. It has quite the naughty vocabulary, from expletives as simple as “Ass” to the more complex “Cocksucker,” if your fingers are nimble enough and expectations for clarity low enough (see video). Leap Frog corrected later versions of this toy by programming it to insert another phrase already programmed into the toy between any of the objectionable letter combinations… pressing F then K on these censored versions sounds like: “Fuh” – “Hyuh, hyuh, hyuh, hyuh… That Tickles!” – “K”

Just a side note, I feel like parents should be more annoyed with later verions of these toys, having to hear “Hyuh, hyuh, hyuh, hyuh… That tickles” over and over, every time their baby happens to hit “F” then “K” or “D”-“I”-“K”or whatever.

Here’s a short companion video to this article:


These toys are a real pain to bend for several reasons. There is a thin, easily-damaged plastic membrane that contains the leads for the buttons in the three rear segments of the caterpillar’s body; kink the membrane and you’ll lose more than half the toy’s sounds.  To gain access to the toy’s brains in the front segment, you’ll have to peel up cardboard and hot glue from the bottom of the circuit board. The plastic feet buttons easily fall out, there is not a lot of real-estate for adding controls, and if the toy’s speaker is disconnected, it messes up the sound. To top it off, there are a number of different (and less bendable) versions of circuitry within seemingly identical versions of these toys. But I know you people out there, you’re like me; you really want to hear this toy say “Fuck” in a James Earl Jones voice and you’re not going to stop until you do. Let’s get started.

The Original Fuckapede, circa 2006

There are several versions of this toy, so it’s critical to select the correct version to bend. The toy we are after will have a green, truly segmented body; the bodies of later models of the toy are made to look segmented but are actually one solid piece of plastic. The revised version of the toy is censored, as are some versions of the ‘Pals with segmented bodies.

This is easier to see than it is to explain, the pictures below show the original and revised versions of the toy.  The first toy pictured below has the body design we want.  There are really glossy plastic versions with this body design that are censored or partially censored.  You want one that is less glossy than the one pictured, at least I think, but really, there’s no way to be absolutely sure if you have the circuit that I’m writing about without listening to and opening up the toy (and probably several):


These are later versions, they are censored, and I assume they are types we don’t want:

alphabet_pal_dont_want.JPG So, if you have a segmented ‘Pal, put batteries in the toy and hit “F” then “K.” If it says “Fuh-K” without saying “Hyuh hyuh hyuh hyuh… That TICKLES” between “Fuh” and “K,” that’s a good sign. The third potential indicator that you have the desired version of the toy is the Item Number. The Item Number is located on the bottom of the rear segment of the toy. The Item Number on the version we want for our nefarious purposes looks stamped or melted into the plastic.  Other versions have the Item Number Printed in black.  So far, I have only found the uncensored, surface mount circuit board in the ‘Pals with the stamped Item Number, though I have found other circuit boards in these as well.  If it’s green and segmented, open it up and compare it to the image below.  The circuit on the right is the one this article covers.

Bendable and Not-So-Bendable Alphabet Pal Circuit Boards

If your toy is uncensored but has regular-sized resistors on the board and its circuit board looks like the one on the left in the image above, you may not find any bend points (I didn’t find any good ones).  But I encourage you to try any way, if you have this version of the toy, and let us know if your results differ.

Now you’ve finally found the version of the ‘Pal that you want to bend (probably after buying and opening several) and you’re raring to go. Don’t get rid of those other caterpillars, they come in handy for spare parts. All I have done to the toy is add a simple pitch bend, but it still makes for good sounds. The Letter Sounds for T, C, K, X, P, and S are nicely percussive. H, M, R and U sound like weird grunts, groans, and sighs. For reasons I can’t remember, the first version I made uses several buttons and switches to connect different (and since forgotten) resistor values in parallel to a 500k potentiometer to create stepped pitch ranges which could be momentarily engaged or locked on (diagram 1).  The lettered resistors in the diagram refers to resistors in my added circuitry, the numbered resistors refer to the resistors on the ‘Pal’s circuit board.  Look at the ‘Pal’s circuit board so that the component labels read right; the solder points in the diagrams are determined by this orientation. I did no de-soldering on this project.

Diagram 1:

Diagram 1

I decided to simplify the bends by substituting body contacts for the buttons and switches for the new ‘Pal I cracked open and bent for this article. I find that body contacts are usually quite expressive as a general rule, but I think the reason I may have abstained from adding them to the first Fuckapede is that they are a tad touchy on the second Fuckapede. They seemed rather stable when I was first putting the second one together, but when I plugged it into my amplifier they caused the toy to crash like crazy. I couldn’t figure out what was causing this problem, so I tried a number of different audio output configurations to see if it would correct the problem. What finally corrected the problem was not changing my wiring but rather plugging my amplifier into a properly grounded outlet. Don’t ask me why this worked, I’m sure I’m breaking one of the cardinal rules of circuit bending by even plugging it into a non-battery powered amplifier, but it seemed to mostly correct the problem (though the body contacts do still seem to cause it to crash/reset from time to time, especially when the potentiometer is turned far to the right or left).

Leap Frog Alphabet Pal Bend Points

Leap Frog Alphabet Pal Loose Controls

Leap Frog Alphabet Pal Bend Lead Placement

Before I wrap up, I’ll add a few helpful hints about bending and decorating this toy. The first thing I did after opening up the front compartment, under the Alphabet Pal’s head, was disconnect the rear button membrane from the main circuit board; I found out the hard way that if you compromise this membrane, the rear buttons won’t work and you’ll have to find a replacement membrane from another Alphabet Pal.  Avoid this by detaching the rear three segments immediately from the front segment and setting them aside to reattach later.

I mounted the output jack in the first Fuckapede’s forehead, but it was a very difficult installation, as you have to entirely disassemble the head. Even though the jack looks really cool there, I had to heat and bend the light-up antenna assembly inside the head to accommodate the jack, and the cord still doesn’t quite insert all the way. If you absolutely must put the jack in the head, you might try mounting it in the side of the head or using an 1/8” or RCA jack instead of a ¼” jack.

Ubiquitous String, Out, 1/4? Audio Output Dongle, In

Another option would be to do what I did in the second version of the Fuckapede, which is to make a dongle for the audio jack. The Alphabet Pal has a string that protrudes from its chest which, when pulled, plays the alphabet song. The string is attached to a button assembly that presses a button on the main circuit board. The string’s handle is almost always broken or missing when you find a ‘Pal. I removed the string and wired the button leads to a normal push-button switch, now mounted to the left of the string hole. I made the dongle similarly to how I make the jacks for my Crème DeMentia Bottle-Cap Contact Microphones and simply ran the jack’s wire through the hole left by the removed pull-string. I coated the jack assembly and some of the cord with hot-glue and Plasti-Dip to give it the look of an organ popping out of the caterpillar’s chest. The eyes were painted using acrylic paint covered with clear nail polish.  The original Fuckapede’s fangs are plastic fork tines.  The new Fuckapede’s beak was stolen from a chicken toy and its tongue made from a rubber band, two zip ties, red Plasti-Dip and hot glue.

The green plastic seems to be very prone to collecting paint scuffs;  they can be removed handily with a Mr. Clean Magic Eraser. There is space to mount controls in the rear segments, but make sure that you run your wires through the hole in the red connecting donuts before soldering them in place. I added a green lanyard to the rear of the original Fuckapede so you could hang it around your neck when playing it, but it’s still pretty awkward to play.  This toy automatically shuts off (and plays an annoying song before doing so) and the time before this happens gets shortened or extended if you have the pitch dial turned up or down, respectively.

Thanks for reading!

New Bottle-Cap Contact Microphones

by Austin

The first batch of 30 Creme DeMentia Bottle-Cap Contact Microphones from sold out within a few weeks, thank you to everyone for their orders!  I have just finished a second batch of over 90, and 10% of them have already sold! Just like before, they are available singly for $15 or in six-packs for $65 from  Some of the new designs are one-of-a-kind and have already sold out, but I may make more of the same designs in the future, especially since some of them do look very nice.  Please have a look:

Creme DeMentia BCM’s Batch 2 Blue

Creme DeMentia BCMs Batch 2 Green

*Smirnoff Eagle has sold out

Creme DeMentia BCM Batch 2 Metallic

*Gold Bird has sold out

Creme DeMentia BCMs Batch 2 Metallic

*Pink Champagne and Smirnoff Eagle have Sold Out

Creme DeMentia BCMs Batch 2 Red & Black

Creme DeMentia BCMs Batch 2 Red and Blue

*Pabst and Heineken are Sold Out

Creme DeMentia BCMs Batch 2 Red & Gold

Creme DeMentia BCMs Batch 2 Red & Green

*Heineken is Sold Out

Creme DeMentia BCMs Batch 2 Yellow & Red

*Destapa y Gana is Sold Out

Creme DeMentia BCMs Batch 2 Yellow & Black

Thanks for looking

Introducing Creme DeMentia Bottle-Cap Contact Microphones from GetLoFi

Creme Dementia Bottle Cap Contact Mics

by Austin

My first exposure to contact microphones was when I first wanted to amplify my autoharp. I found a contact mic from a local guitar store and used it for a while. I use a magnetic autoharp pick-up now, because I found the contact microphone amplified the noise of the bar chords being pressed and the loud clack of my belt buckle against the body of the autoharp. The contact microphone did work to amplify the vibrations within my autoharp, however, and I used that pick-up for many months.

What I now understand is that though contact microphones can loudly amplify some unwanted sounds and may not be ideal for some instruments, they can unlock and amplify the hidden sounds within everyday objects; they are a dousing rod for unearthing an entire world of new sounds and instruments. At Bent Fest 2007 I got to see Tim Kaiser perform for the first time. He proved to me and the rest of the audience the vast sound potential within a contact microphone, some hand-selected/-crafted objects, and lots of delay. He and Logan Erickson also hosted a workshop at Bent Fest 2007 on using contact microphones. The big lessons I took away were “listen with a stethoscope to find good placement” and “make good, solid physical contact with the device and the contact microphone.”

So, what goes into a contact microphone? A contact microphone can be made out of just about any piezoelectric disc, which is a brass disc with a smaller wafer of crystal soldered directly to one side. When the crystal vibrates, it releases an electric current. The crystal translates vibrations from objects it touches into electric currents, which travel through wires to your amplifier. It is similar to the way a regular microphone works; a paper cone vibrates a magnetic coil, which in turn creates a electric current. Piezo-electric discs, however, sense vibrations directly from the object itself, not the air the object is vibrating. This allows them to amplify minute vibrations from within tiny objects that we would otherwise not be able to hear well through the air. Piezo discs can also serve other functions as well, such as velocity sensitive drum triggers and drivers that will physically vibrate objects.

There is a wonderful, in-depth chapter on piezoelectric discs in Nicholas Collins’ book Hand Made Electronic Music. This book is a must-read. In it, he details how to make contact microphones. He recommends soldering a piezo-disc directly to a shielded audio cable, then dipping it in Plasti-Dip. My friend Mike Taylor (or Mic Tailor, if you will) and I made a couple of contact microphones this way, in 2006, using broken audio cables I had found at a thrift store and some piezo-discs from American Science and Surplus. Mike and Matt Dotson used several of them to put on a performance of John Cage’s “Cartridge Music” at a John Cage symposium here at NIU, using them in place of phonograph cartridges. Phonograph cartridges predate piezo-discs but essentially do the same job, amplifying tiny vibrations. The mics we made were decent, but not great. The discs were very thin and relatively small in diameter; even with a couple of coats of Plasti-Dip, I still ended up snapping the crystal wafers on some, thereby ruining both the mics AND several long, shielded cables. In a second attempt, I did better, but not best – I filled a bottle cap with hot-glue, placed the piezo-disc in the glue, and dipped the entire assembly. They ended up looking something like chocolate covered Oreos on the end of a guitar cable. I solved the durability issue, but the hot-glue filling the cap slightly dulled the piezo-disc’s sensitivity.

Now, back to Bent Fest 2007, the first time I met Nick Pelzwik. Nick had a display with a circuit-bent wobble television and some circuit-bent Barbie Karaoke delays. At Circuitastrophe 2008, I saw Nick again, and this time he was armed with a ton of delightful contact mics. Nick’s solution was simple, but ingenious: A Plasti-Dipped piezo disc soldered to a 1/4″ jack inside a protective cap via some short wire leads. They look and sound very good. Nick performed at Circuitastrophe using them on a trumpet, toy piano, his own throat, and other objects to produce a very rich soundscape. Nick makes and sells these on eBay, I might add.

Nick shared with me his source for good quality piezo-discs, so I ordered a bunch in the hopes of trying to improve my initial design. I found that these discs were wider in diameter, coincidentally the same diameter as beer bottle caps. The discs that I had used before were smaller in diameter than the bottle caps, causing me to pool the hot glue into the caps. Now the discs rest only atop a ring of hot glue on the crimped circumference of the bottle cap. This allows the discs to vibrate more freely than before while still remaining somewhat protected from breakage by the bottle caps. Instead of soldering directly to a shielded audio cable as I did before, I soldered to a short length of wire which connects to a 1/4″ jack housed inside two facing 2-liter bottle caps zip-tied and hot-glued together. So, the result is a solid, protective housing for the piezo disc and jack, made from mostly recycled materials, definitely following the re-use mentality of circuit-bending. The beer cap allows you to hold the piezo-disc firmly and directly to objects like a stethoscope without finger noise and to even use it like a guitar pick without the worry of snapping the crystal. I’m also happy with the two 2-liter cap solution for housing a 1/4″ jack; they are pretty solid once attached with zip ties and hot glue and very colorful.

Single Creme DeMentia Bottle-Cap Contact Microphone

Six-Pack of Creme DeMentia Bottle-Cap Microphones

I have made about 30 of these for starters and they are available at the GetLoFi store for $15 apiece or $65 for a six-pack, shipping included. And now, here they are in action:

[youtube][/youtube](Note: In the video the magnetic autoharp pickup is not being used, a Bottle-Cap Contact Microphone is clamped to the autoharp.)

Get yours today!

More Information!

Circuit Bending Casio SA-39 with LTC1799 Precision Oscillator – Creme Dementia

By Austin

This is my first successful attempt at pitch-modifying a Casio keyboard using the LTC1799 Precision Oscillator Kit. The kit oscillates at frequencies from 1KHz to 30Mhz and its output frequency is controlled with a potentiometer. The oscillation frequency from this kit can be substituted for the constant oscillation frequency a device receives from its internal crystal. The kit’s variable frequency will allow you to control the pitch of a device when it is patched in place of –or sometimes in parallel with—the device’s internal crystal. Spunky Toofers is currently using these LTC1799 Precision Oscillator Kits as pitch controllers on his Casio SK-1s and SK-5s. also makes a similar kit, the 555 Timer Kit, which has a frequency range of 1Hz – 2MHz. The 555 Timer Kit can also be used to send a “counterfeit” clock signal to crystal-controlled devices, but the frequency range is lower and more narrow than the LTC1799 Precision Oscillator Kit. This lower frequency range, however, is partially within our hearing range, making the 555 Timer Kit suitable for direct audio applications. The 555 Timer Kit seems to work well with Yamaha devices, but not so well with Casio devices.

Both Yamahas and Casios seem to like the LTC1799 Precision Oscillator Kit. I installed the LTC1799 Precision Oscillator Kit in a Casio SA-39 Keyboard. The Casio SA-38, -39, and -21 all appear to be the same keyboard, are quite common, and can easily be found for less than $5.00. Their features include a nice selection of tones, a wide selection of rhythms (though no rhythm fills, oddly… perhaps there is an easter egg for those? Anyone?), 5 drum pads, and a 1/8” out. It also has stereo speakers, which is nice if you want to remove one for space.


Fitting the LTC1799 Precision Oscillator Kit to the SA-39 took a little fine-tuning. The kit comes equipped with a 1M potentiometer, but the range of tuning with a 1M pot was rather narrow when controlling the SA-39. After some experimenting, I decided on a 50K pot and 10k pot in series in place of the kit’s 1M pot, producing a wider tuning range and course/fine adjustment. I later added body contacts in parallel to these two pots (not the crystal) and they are quite expressive and stable. The 50k and 10k were values that were handy, I think that perhaps a 20 – 25k and a 5k might make a comparable, perhaps improved control combination. Normally the LTC1799 Precision Oscillator board mounts behind the included 1M pot, here you’ll see it is simply hot-glued face-up on the SA-39 circuit board.

With this configuration of 50k and 10k, however, there are still dead zones at the high-end and the low-end of the dial; the keyboard will want to glitch out and sometimes die or freeze when you dial in too high or too low a frequency. Above and below a certain frequency range the keyboards just won’t function “normally” and will start to go hay-wire. You can then control the pitch of the ensuing glitch if the keyboard doesn’t choke. A trim pot could be used to set the upper limit of the frequency range.



A +5V point on the SA-39 circuit board was found by probing with a multi-meter. You can see this point on the SA-39’s circuit board with trace side facing out (+5V). The lead connects to one lug of the 10K Pot. Attached to that same lug are leads to one of the Body Contacts and to the LTC1799 Precision Oscillator Board’s power input. The Precision Oscillator Board also has a ground connection.

The keyboard’s crystal is removed and hot-glued to one side (Original Crystal). Probing with the Precision Timer’s output helped determine which of the 2 holes left by the vacated crystal gave the desired control over the keyboard’s pitch (it is the top hole, with the keyboard laying open, face down). A lead from this point is soldered to the middle lug of a toggle switch, with the two side lugs leading to a) the Precision Oscillator’s output and b) the original leg of the crystal that had been in that hole. The remaining leg of the crystal is reconnected to its original hole with a lead. When the toggle is up, it is connected to the crystal and functioning normally and when down, the keyboard receives its pitch frequency from the LTC1799 Precision Oscillator Kit.

In looking around online, I have seen a number of different bends for these keyboards. I believe there is a point-to-point distortion on the board that changes with variable resistance. There is also a way to make it glitch, I have seen this done with both body contacts and pushbuttons. I assumed this could be done by simply bridging the two legs of the crystal momentarily, as is some times the case with Casio keyboards, but I didn’t have any luck in my tests. Please, dear readers, feel free to comment on the location of these other bends.

The pictured keyboard is already in the hands of the band SSM, who I went to see in Hamtramck, MI, recently. I didn’t get as deeply into this keyboard as I would have liked, as you can tell from the last paragraph, but this configuration made for a quick and expressive pitch bend. There is also somewhat reliable glitching that can be dialed in at the high and low end. I have several more of these keyboards, and my goal is to get some more of these distortions and instant glitches mapped out. You will see my future work documented here at Keep those soldering irons hot!


High Res Diagram:
Inside Casio SA-39 with LTC1799 Precision Timer Kit

Creme Dementia’s Recipe for Circuit Bending the Protech Drum Toy RY-1286T, pt. 1


Greetings LoFiers! Tommy from Roth Mobot supplied me with a dupe of a toy I’ve bent before, the RY-1286T Protech Drum Toy. Tommy has the best toys.

I’m very fond of the Protech Drum Toy (or the “RY-1286T” if you read it’s most likely peeling label on the back), and it has special significance for me, as it was the first toy that I ever circuit-bent. With instruction from Patrick from Roth Mobot at a free workshop in 2005, I was able to find and figure out how to wire a pitch bend and a noise/buzz bend. Thus was born the Drum Invader, and it remains one of my favorite projects to this day, here it is in action:

The toy pretty much looks like this when it’s not bent, minus anything silver on the outside you see in the video. There are no star stickers, either

Here’s a picture of the circuit board of the Protech Drum Toy that I bent. It’s followed by a schematic drawing of my bends, and an explanation of these bends.

Circuit Bending Protech Drum Toy

The Bends Explained:

A nice pitch sweep can be attained by soldering a 1M potentiometer in the configuration shown, using leads from the right sides of resistors R3 (center lug), R1, and R5. Nicely responsive body contacts can be installed using those same points. What really makes this toy sing, though, is the noise/buzz bend. By connecting the top (-) leg of C3 to J7 on the board, you get a loud buzz. By varying the components between these two points, you can control the timbre and volume of the buzz. I used a 15k resistor and a 473 capacitor to get two different buzzes. Try some other components! These buzzes are, for some reason, affected by the pitch bends. This essentially gives you two different wave forms that are pitch-controlled by the potentiometer and body contacts. The most interesting tones result from masking the the drum tones with these noise bends; the rhythms created by the toy “modulate” (not sure if this is the correct term, but you get the idea) the buzzes, creating rhythmic buzz “melodies” out of the drum beats.

Circuit Bending Protech Drum Toy

So, you may ask, why am I re-opening this toy now? For starters, some joints were poorly soldered and it’s beaten up from touring. Also, despite its excellent bending potential, this isn’t the most well-designed toy on its own; the small buttons that allow you to record patterns for playback and select rhythms and drum pages have a tendency to stick down and the on/off switch has a tendency to get really staticy. I think it’s ripe for a re-house and I think I may do the both of them simultaneously, creating one Amalgam of the two toys. So, why not document my progress for all you happy people?

We’ll call that Part 2.

Creme Dementia’s Recipe for Bending the Sesame Street All Star Band by Golden

Greetings all you people out there in Internet Land! This is Austin, aka Creme Dementia, and this is the first of hopefully many posts that I will be making for I’ve been circuit bending for about 3 years now and this is probably completed project #12 or so. I was introduced to bending by Patrick of Roth Mobot, while living in Chicago, and through him I have met many other benders. Daniel, aka Spunky Toofers, inspired me to start tackling obscure toys, ones that I haven’t seen bent much or that are just pretty whacked-out to begin with. The Sesame Street Keyboard is a good example of a pretty “whacked-out to begin with” toy, and the bends that I have found make for a lot of fun with the toy. I have come across 2 of these toys in my thrifty adventures; with the help of a third from eBay, I was able to Frankenstein-together the finished result you see. If you take the precautions I list in step 1 and solder quickly, I think you will probably only require 1 of these toys to bend it as I have.

I wrote this in a step-by-step manner in an attempt to make it accessible to beginners and pros alike. If it’s TMI, so be it, it’s better then TLI. My custom paint-job was done by splashing red nail-polish across the surface and adding several coats of clear-coat (I masked off the “On” button and keys with masking tape and newspaper). I did the eyes on the Sesame Street Characters in a similar manner with white nail-polish, markers and clear-coat. To mount the PCB buttons, I made a paper template and marked and drilled the holes for each leg for each button. I then soldered two leads to each, fed the leads and the legs into the holes, and put a dab of JB Quik Weld epoxy putty under each button to hold it on securely. Otherwise, this is all pretty simple, save for de-soldering. I’m sure you could creatively skirt having to desolder anything in this project, but I found it made things easier for me. I enjoy desoldering and its a good skill to learn if you haven’t yet. Treat yourself to a desoldering pump, it’s a great gadget to have around.

Alright, so here we go:

The Sesame Street All Star Band Unmolested:


Bending The SSASB

1) Before you open the toy, here is a list of some key precautions and some notes on my bends; read these instructions thoroughly before you get started. There are two shorter screws in the outer case, those go in below the numbered rainbow keys. A good way to hold onto your screws, as taught to me by Patrick of Roth Mobot, is to stick them to the toy’s internal speaker, but I’d get a container for them if you plan to have the toy open for any more than a day.

There are several ribbon wires and plastic membranes with printed traces inside the toy, be very careful not to bend or break these, as they could easily disable the buttons. I went through 3 of these toys before coming out with the finished product, and I think one the problem I encountered may have been from unknowingly breaking one of the wires in the ribbon wire. I encountered a membrane breakage in another toy, the Alphabet Pal (Fuckapede… see my MySpace page. Also, I do not give specific capacitor values for the last bend in these instructions; the values you could choose are rather open-ended. You’ll want to either experiment with a capacitor substitution box to find the values you want or experiment with capacitors that you have on hand. All the values I used were below .22 uF. Also, there is an auxiliary battery compartment with button cell batteries under the main circuit board. I removed these batteries and the leads traveling to it; I assume they were put there to power the toy at the point of purchase. When you load in AA batteries, the batteries push open a switch that breaks the connection to these auxiliary batteries, which are left to rot inside the toy. Most likely they are dead, as this toy is from the early 90s. Test them for charge and dispose of them properly if they are dead. Don’t just throw out those batteries, collect them and give them to the Lion’s Club or Radio Shack or Walgreens or the Fire Department or SOMEONE for proper disposal.


The SSASB Circuitry Bend Points

2) Looping –

Solder leads to pins 13 and 14 on the Sesame Street All Star Band 9124 Chip. Connecting these points will give you looping sounds. I wired a toggle and push button switch in parallel which would connect these two leads through a 47 ohm resistor, so that you can audition and hold loops.

I used solid core CAT5 strands to solder to the chip; they solder quickly. Quick soldering is key to avoid overheating and damaging the chip, which may also have been the culprit behind the problems I encountered in my first attempts at bending the toy.


My Control layout inside the SSASB Handle – It’s about the most open space you can find inside the toy.

3) Body Contact and Pitch Switch –

Desolder R6 from the SSASB Keyboard circuit board and retain it. Solder a wire lead to the remaining hole where R6 connected directly to C3. Connect a second lead to the loose end of this lead. Mount an on-off-on switch (SW1) in the case and solder the joint of these two leads to the middle terminal. Mount a body contact in the case and solder the remaining lead to it.

4) Pitch Switch Continued –

Attach the desoldered R6 to one of the outer terminals of SW1, and solder 2 wire leads to the other end of R6. One of these leads will connect back to the SSASB keyboard, soldered into the other remaining hole where R6 had been removed. The loose lead will connect in the next step.

SSASB Pitch Dials – I put these on the left side of the keyboard

5) Pitch Dials –

Mount three potentiometers in the case, two (or more) 1M potentiometers and one 5K potentiometer. Wire them in series, and add a 180 ohm resistor at the end of your loose lead and solder the other end at one end of the sequence of three potentiometers. At the other end of the potentiometers, solder a wire leading to the remaining terminal of SW1.

6) Capacitor Bay –

C3 on the SSASB Keyboard also affects the pitch when you connect other capacitor values in parallel with it; they drop the pitch into a different range. I added 4 PCB momentary buttons that put 4 different capacitors in parallel with C3. I would recommend experimenting with different capacitance values to get the sounds that you want.

7) Cut the positive lead from the AA battery compartment and add a reset switch (the looping can get crashy). Add an output and possibly a speaker switch and you are all done:



SW1 will give you three modes, Normal, Pitch Controlled, and Open. Normal mode is when you route it through the pole that R6 is soldered to. Flip it that way and turn the toy on. Press a sound, and during that sound, move it to “Open” (off). This will give you a long stream of noise that will last for quite some time. Move it to the last position, Pitch Controlled. Turn the 1M potentiometers so that they are at 0 ohms, move the 5K potentiometer to center and it should sound about normal. The 5K potentiometer will give you pitch control over the sounds above and below its normal pitch range, while retaining the integrity of the original sounds. As you add more resistance with the 1M potentiometers, it will get that shimmery quality of the noise stream caused by breaking the pitch circuit in “Open” position. While the toy is making a noise, hold down the looping button. If the sound starts looping, you can lock it on with the looping switch. Play with the controls in tandem, there’s quite a vast sonic range.

PLEASE, use this is as a jumping-off point and experiment, you might find a preferred layout or different control options.

The draw to me for this toy was its strange appearance and all its great factory tones, its easy dis-assembly and the fact that it’s made by Golden. More on that later. Thanks for reading, I will hopefully have some video of my bent toy for you to enjoy soon.

Da Da Da da-da DAH *SMASH* Oh Boy!