UNBENDABLE MACHINES list here.

[egr]

Fisher Price "Tune In TV" , Sesame Street version:  It's got some kind of automatic reset that I can't bypass and pretty much ignores any bending attempts (by me at least)

Too bad 'cause it's got a simple remote control that I was really excited about.   

[Gleix]

Leapfrog learning drum... black blob chip without pitch bend and BARELY a distortion by poking things on the speaker wire.  Still a fun little toy though 

[shimshon]

"Music Learning Module" produced by Wurlitzer. a decent looking keyboard from the outside, but not much going on inside. there are a bunch (six or so) chips inside, which gets one's hopes up upon opening it, but the chips only output one specific note from each pin, meaning it's all sample based and there's no way to alter the sound. i don't think there's even a filter section, i think it goes straight from the chip to the output. it sounds sort of square wave-ish, but a bit warmer.

the one nice thing about the keyboard is infinite polyphony. the samples interact in a weird way though. when you play intervals that aren't perfect, you can hear where the waves cross paths and almost creates a rhythm of its own.

a neat electric organ for $15 at goodwill, but not a bender's toy.

[Gordonjcp]

"Music Learning Module" produced by Wurlitzer. a decent looking keyboard from the outside, but not much going on inside. there are a bunch (six or so) chips inside, which gets one's hopes up upon opening it, but the chips only output one specific note from each pin, meaning it's all sample based and there's no way to alter the sound.

Can you get a note of which chips are used?  It's probably not sample-based but divider-based, if it's quite old.

[reign16]

Oh thank you for listing the unbendable machines, how about the YAMAHA PSR-700 what is you can say about that, cause i am planning to buy an YAMAHA PSR-700 maybe this coming March or April,, So i am asking some advice to you guys, Thank you for your advice in advance...



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[SineHacker]

I opened up a 'Blue Man Experience' keyboard today, first of all it was an absolute nightmare to open because of this useless pipe framing it has - I then proceeded to mess around with the circuit board for a couple of hours with only minor results (the board as a crystal on it I think and I managed to get it to glitch out like a really lame voltage crash after trying to calibrate it for hours) if anyone has had any better results let me know!!

[S-CAT]

There is a good example of a circuit bent Korg DDM on you tube, no points for guessing who did it. It is a very awkward unit to work with and I found a crazy method to get the results.

Funny, the Korg DDM110 was the first drum machine I ever circuit bent.  They're almost trivially simple inside, with quite a few cool bends.  I sold mine after restoring it to its "normal" condition a few years ago.  Be careful, because there are relatively high voltages around the analogue section that will zap the logic chips - the "poke and hope" method is not your friend.

Basically I poked around until each percussion sound dissapeared and the with some more fumbling managed to get each sound back by jumping wires to each of the chips and resistors, I then noticed that the sound was only coming from one channel and decided to bridge the stero signal into mono on the board, the next strange thing that happened is that the hi-hat level started to generate bass tones when it was turned up fully. And when a 1/4" jack was placed into the headphone socket the machine reacted differently again. I've got another one here that I am working on but it's a slow process.

You really can't just poke randomly at it.  Get hold of the data sheets for the chips and work out the circuit before you start randomly stabbing things.  These DDMs are getting rare, and are a bit fragile electronically.  Maybe it's best to leave it to people who know what they're doing.

I have now got the plans for this, so you could sy that next time I do it that I would know what I was doing. Haveyou managed to modify one of these units?

[sk-1]

I disagree now about the Bontempi 666 range being unbendable.  I've had mine for a week and although I'm yet to bend it, I'm already experiencing random glitches happening with the sound selector buttons and the on/off buttons.  The Bontempi BT-605 has some major bugs in it and it is very easy to mess up the sounds and operation of the entire keyboard just by switching it on, then off multiple times in combination with pressing buttons and starting the demo, rhythms, etc.

So far, just by randomly pressing the buttons on the Bontempi, I have managed to get the keyboard to glitch and malfunction with around 9 different and repeatable bends.  Also, there are some unpredictable glitches that occur with the power on and off buttons and sometimes you get a loud scream from the speaker or a long, continuous and full volume organ sound when switching it on.  On one occasion I managed to get a low-volume sound that was like a continuous matrix scan, or random arpeggiator noise that was very, very fast and partially musical.  It reminded me of the bug on the Hing Hon when you press down multiple instrument buttons and it cycles through them all in like a super-fast arpeggio.

If the Bontempi can glitch and malfunction just by pressing its buttons alone, I can imagine just what could be achieved once I get in there and really have a good go at it.

*edit: I'm thinking that some of the bends in a Bontempi might also need to be wired up at a button level... because with these strange button combinations, it might be possible to attach pots and components to control whatever it is that is happening here.

[Jayman9er]

I recently got a good deal on a leap frog leap pad. that was before i new about this site i read the unbendable posts, and seen the leap frog  in the list. I have got some good glitch sounds out of it but limited, when i get a sound i like it shuts itself off. Should i toss it or am i doing something wrong. Any advice would help thanks.

[Circuitbenders]

you could try sticking some low value resistor in line with your glitch bends, or possibly a diode, but i doubt it will help much. Leapfrogs are just a pain.

[Jayman9er]

thanks for the advice i will give it a try, sorry about the anoying question. I am still a rookie and will try not to be to annoying with dumb questions. I appreciate the response

[freeform delusion]

The Bontempi B30 is a really bad keyboard. I don't like the way you unscrew it and then you have to slide out the insides, it does look interesting & better that way, a kind of skeleton keyboard.
Didn't last long with me, it is also disguised as a Barbie Keyboard in the same shape (but pink), and has the same functions (which do sound good though) but didn't find much for bends myself.

I also found the PSS-30 hard to bend too.

[kitsophrenik]

http://matrixsynth.blogspot.com/2010/05/squidfanny-circuit-bent-yamaha-pss-30.html

says up there ^^^^^^^^ tht pss 30 is unbendable.... this one is well and truely bent!

also, this guys a genius!

love it!

=)

[Timodon]

Holy F**k!

bits of that sound like Holy F**K!

Quality instrument! want one now!

[kitsophrenik]

innit! its a genius sound!

you should hear it amped up to fcuk! mintttttt!

=D