Hannah Montana Electric Guitar – circuit bending

I went thrift shopping the other day and I found a pretty cool toy that looked like it would be great for circuit bending. It didn’t have batteries when I found it so I didn’t test it out at the thrift store. I should really bring batteries with me or have the attendants test them at the store but hey… I can always use another toy for my circuit bending collection.
Hanna Montana Circuit Bent Guitar

The thing that caught my eye about this Hanna Montana electric guitar is that it had an echo knob. This could only mean that there was some kind of ic chip that handles the delay. I had to have it.

I went strait home, powered her up and started pushing her buttons. She sucks. The main problem is that all the buttons on the “fret board” are sound effects. Now, this would be awesome if you could just use the sound effects in a circuit. But you can’t. When no sound is being played and you push one of the sound effects buttons, the first press triggers one of 3 Hanna Montana songs to start playing. This is bad. Really bad.

I don’t know what the name of the three songs that are programmed into the circuit but I now know the words. I figured it was odd that the sound effects triggered the songs. So, I youtubed the guitar and found a video where it seemed (to me anyway) that the sound effects could be played independently. This sparked me to spend the next two days trying to find a crossed wire or short circuit somewhere that could be fixed.

I found nothing.

I still think that there is a bad connection somewhere but I can’t for the life of me figure out where it is. So the circuit will forever play one of Hanna’s crap songs.

There is a silver lining to the purchase of this piece though. The circuit has an independent circuit that controls the volume (via an lm386 of course) and a chip that does in fact create the echo effect.

That chip is my dear old friend, the pt2399.

pt2399 chip inside the Hanna Montana Circuit Bent Guitar

It has some different identifying letters but it’s the same one. You can see that the circuit design is much like one of the schematics in the 2399’s datasheet. It’d has only a potentiometer controlling the amount of echo but that could be changed with little effort.

The point that I wanted to make was that you could easily get one of these Hannnas and strip out the echo circuit and use it on any project you like. The circuit must be very similar to the one found in the Barbie Karaoke machine. You might be able to use the schematics and diagrams found at http://casperelectronics.com/finished-pieces/barbie-karaoke/.

If you are interested in playing around with the circuit, I mapped out some of the main controls for the primary voice chip inside the guitar. That and the lm386 amplifier circuit. As seen below.
Hanna Montana Circuit bent guitar - schematic
click on the image to enlarge.

Happy Bending!

15 thoughts on “Hannah Montana Electric Guitar – circuit bending

  1. Nice find. I think you should pull the usable stuff and build a new thing in it that uses the fret keys and such. Maybe build a little synth into it. 😀

    Speaking of PT2399s, I’ve got like 10 in my collection now, waiting for me to get around to them. The delay circuits are so complicated for what you get in the end, ya know? 😀

    • It took a little work for the delay circuit but it’s so worth it.

      The depth you get with a little delay is awesome.

      I am a guitarist too. I use my BOSS digital delay for everything… I just love delay.

      But I know what you are saying about time put in vs value pulled out.

  2. Hey! I’m actually almost finished with my bend of that upsetting Hannah Montana guitar. It’s not repackaged (their horrible design, I scrapped the whole guitar format) yet, but if you like I can send you pics of what I’ve got so far. It’s a mess, but hey, it works. And it’s a far cry from what it was. Total of six knobs and five in/outs as of right now..

    Great site! I’ll be digging in fully on my next break.

  3. I would LOVE to see pics of your bends!

    That sounds totally awesome. Pics of the inside would be great too. I love to look at HOW people did stuff also.

    Do the sound effects buttons on your guitar also trigger one of the three songs?
    I ask because I want to know if it is just my guitar that is busted of if it is a feature of the circuit itself.

    Thanks for the post!

    • Actually, I managed to fall backwards into what might be the best bends you can do with this thing. Granted it took a couple days, but so far (still going, still going..) but I essentially gutted and pieced all the boards and put them back together. I hate those standard ribbon cables. Two bends and they’re done for.

      I found every possible sound on this thing I think. All the guitar riffs, instrumental jams, those god-awful Hannah tunes (let’s sing together, shall we?), the individual guitar notes, and additional octaves. Your diagram is fantastic, but it’s too small to read the fine print. You and NoysToise have great penmanship. Assuming you possibly studied some?

      Feel free to email me, MagnificentPrick at gmail, and I’ll save your readers my blathering until I can produce a finish piece, assuming it lives that long..

      Can I post pics on here? I don’t have anything linkable yet, just a few taken with my iPhone and a magnifying glass..


  4. I would love it if you would post some pics. I don’t know if you have to format it into html or if you can add them or what. Not sure.

    I fixed the Hannah Montana guitar schematic. Now it opens a larger pic when you click on it.

    You can “blather” as much as you like on here. It might bring some more readers and it might open up interesting discussion. I can’t tell you how many times I have found useful info by reading the comments.

    So, you were able to isolate just the sound effects? I thought that it would make the coolest little sequencer sound effects toy. That’s why I spent so much time trying to figure out if the thing had a crossed wire. A 555 timer/4017 counter and a patch bay would be the best!

    Those Hannah Montana songs are the worst. THE WORST!!!

    Thanks so much!

    • i have had good luck with them…i pitch bend the silly songs and effects wich sounds pretty wigging!!!…and really warp out the echos…you can find some of the vids at supeross077 on youtube
      DeMenTia laBs

      • Nice work… Nice shades… Great bends. How many effects pedals are you running that through?

        The one thing I go for in my bending is reliability. I strive to create stuff that isn’t just a bunch of crossed wires. I like to engineer actual working instruments that can integrate with others projects and create some actual music. Synths, arpeggiators, sequencers… that sort of thing.

        I don’t subscribe to the Reed Ghazala philosophy on circuit bending. Too random for me. But to each his own.

        I would love to see some documentation on your guitar. Were you able to isolate the FX keys from the annoying songs that get triggered when you press them??? If you can figure that out… I will buy one off you.

        Happy Circuit Bending!

  5. I have to admit, I was really intrigued by the “strings” on this toy, which actually turned out to be complete smoke and mirrors. Not that I expected real notes, but.. Ew. Anyway, I replaced both resistors on the main “black blob/gumdrop” board, one being the clock resistor, the other being the volume level for the triggers! Yep. With that pot there, you can get all your clock crashing delayed “check (check.. check..)” on. What’s even better, I replaced the four LEDs (and resistors) with various lights, one of which is a “rainbow” LED that pulses through the colors at two speeds. With the trigger pot all the way down, you can use the visual indicators of the LEDs as they scream in the Hannah Montana hell that only they can hear, not you, anymore, thank god.

    That being said, you get f*cking sweeeeet effects from the faux shaping/modulation of the sounds, should you choose to replace a resistor with a CdS photocell or the like. I like to wire one in parallel with nose/one leg of a pot lately, which gives you a perfect blend of light/dark play from bit-crushing ones and zeros (plus body contact = fizzy lava) to hyperbabble that will pop any nearby mosquitoes and likely whip your neighborhood dogs into a frenzy.

    So, including the original three pots; volume, mic level, delay, I added a 1k for “R2” on the blob board (can we call this something from now on or am I just that sleep-deprived?) which is your effects/triggers/sample volume, a 100k with anti-crash resistors for R1, your clock, as well as a 100k for R10 at pin 6 (?) of the 2399, which is a wee bit skittish, but I’m still ironing it out. Let’s see, yeah, the four new LEDs, one being a blinker blobbed off in hot glue after being sharpied purple save for a tiny iris for pinpointing, and for now is tucked away under the board while I work to keep the tones long.

    Here’s where I’m frazzled and losing my attention span; The delay turns off according to some timer elsewhere in the circuit. From what I can trace back to it (as you can see I cut away everything I didn’t need, direct inspiration from NoysToise), it may be in the damn black blob. Anyone got clues? I read on someone’s circuit bending blog post (my bookmarks folder is wrecked) where they remedied this, but I can’t for the life of me track it down..

    Lastly, I’m considering housing the b*tch in a thin-walled wooden box with a piezo contact mic as the default input to the 2399, which I’ll likely get all Folktek-y (to the best of my ability) on with springs and scrap metal and all that mess. And of course it’s got both in/out cutout jacks. Now I just have to take the smaller keys I cut from another toy, solder it up, and start the final stages.. Unless someone can tell me how to disable the kill-switch on the delay chip. Do I just cut the trace and give it a proper voltage regulator? Bump the juice up to 6v and let a 7805 or whatever do the micromanaging?

    I am not kidding. If I hear those songs in my sleep, I will wake up murdering.. “It’s a perrrrrfect day…”

    (please don’t tell me if I have the lyrics wrong. I want to forget.. although she sounds pretty hot as a demon whore, I gotta admit!)

    • i would trace the power from the 2399 (pin 1) back or just cut it. Solder your own power into it from that batteries with a regulator (5v) in between.

      The cut off might have to do with the “demo function”. Or, it might be part of a gate somewhere. Maybe a transistor cuts off some juice to the 2399. I’m not sure.

      Best just to give it it’s own power and see if that works.

      AH HA!!! Just found this…
      hannah montana guitar review

      and it clearly shows that the sound effects can be individual. I have a short somewhere. I know it.

      “it’s the best of both worlds” -Hannah Montana

      • Nice! And yeah, there was that second wire to ground I now remember doing away with, which may have been the opposite thing to do. But I also wanna say I remembered and put it back at -V and one of the pads on the blob chip, perhaps labeled COM? I’ve glued my shit together so it’s hard to say. My pin numbers are covered as well, but from cloudy memory I wanna say if you connect 10/22 you stop playback (very useful, so I’m keeping that in my new keys layout), 10-13 connected to 22 and 20, sequentially, will give you the 8 notes they make available to you. But, looking at your schematic, we may have different markings. So, going left to right, blob facing you, left-most pin being “pin 1” for this example, I was able to switch all the various sounds by making connections at the following:

        Pins 2,3, and 4 (from the left, again, not by actual pad name) to pins 8 and 9 will give you indicator sounds that things are being switched. The pins to your right will be driving the LEDs for half of the sounds, so you can jump into those for some nice glitches with your clock pot twistings, but when it’s in riff/jam/instrumental mode, all the pads to the right will become one-shot guitar licks and other such metal wankery we all know and love HannaMo for.

        I’ll get back on her tomorrow and refresh my memory. Gonna get out of the lab and rest my eyes.

        I feel like we accomplished something here, you know? Cheers.

      • I think I may have my schematic backwards. After this little chat, I’m gonna pull HaMo back out. I think I can make her sing (or not sing as it is in my case).

        I want those sound effects isolated.

        Thanks for all the help!

      • I’m about to start finishing mine up and re-housing it in an old VHS clear case.. I think. We’ll see. First I need to install the new matrix keypad.. Hit me up and I’ll try to get you a schematic of some sort.. Good luck!

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