Circuitbenders Forum
Circuitbenders Forum => Circuitbending discussion => Synths & Samplers => Topic started by: BazTraD on January 12, 2006, 01:48:13 PM
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Hi, I'm new to this, and have aquired 1 of each of the Casio keyboards (SA-1 & PT20).
Does anyone know how bendable these are as I'm desperate to give it a try?
I opened up the SA-1 and started touching the solder points and managed to tune into Talk Sport,
which was hilarious. I did manage to corrupt it a few times that sent it on a crazy random drum path which
was really cool, but I'm not sure how to do something purposeful that I can mess around with.
The PT20 went over my head a bit as the circuitry is pretty vast for such a wee thing.
If anyone can give me some hints or tips on what can be done, it would be greatly appreciated.
:)
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Try a voltage drop crash on the SA-1, they are the kings of this bend. Check the tips pages on the site for details of how to do this.
Never opened up any casio PT so can't help with that one :-X
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Heya. just joined & excited! Is there anything else that can be done to an SA-1? (I noticed 2 switches on it)
Cheers. :)
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errrr, as far as i recall on our SA-1's one switch turned on some kind of wild feedback oscillations and the other was a low pass filter or 'top cut' switch. Not entirely sure though, i'll have a look around and see if i can find any notes.
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I'm just asking cuz I've never bent anything before, is it safe to poke around in it?
Don't mind finding bends myself just worried to break it.
It came in the post today, I love it! Will install the voltage drop crash tomorrow.
What's a good place to solder the pot in?
Can it be done without cutting a circuitboard track?
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As i recall theres a jumper wire on the far right of the circuitboard (back off face down, keys towards you) that can be cut and a 1K or 470Ohm pot soldered across the gap for the voltage drop crash. I think thats where both the battery input and the external PSU input reach a common point. The Sa-1 is a difficult one to break so you should be fairly safe.
This is all from memory though so i could just be making it up :)
I've heard that lazer sound on loads of things, its a brilliant noise. ;D
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Hey man, thanks a milliion! :)
Still didn't get round to doing it, been sampling it just in case...
Been feeding Ableton Live with SA-1 grunge all day - WOW.
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been staring at the PCB till I got a headache.... still don't see it.
There are two jumpers (guess I could try cutting them can always solder them back if it's wrong.)
Also there's a diode around there as well (presumably for protecting against wrong psu polarity). That's the only place where I can see the vbattery & the PSU come together. But it's tricky some of the tracks run under the keyboard rubber contact strip.
?
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(http://www.circuitbenders.co.uk/IMAGES/SA-1_pcb_top1.jpg)
That jumper wire just to the right of the word SPEAKER is the one i'm talking about. Cut that and wire a pot accorss the gap.
I can't remember where that image came from but its from some circuitbending site so if it belongs to someone who recognises it, let me know and i'll credit it to you.
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Wow! I thought you meant that one ("far right") but wasn't sure....
I just Googled my @$$ off but no joy, finally checked back here...
This must be good karma for helping noobs on the Ableton forum. :)
Thanks a million!
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Ha! It's working! :)
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Hey guys,
Thanks for the responses, and the good advice.
Sorry for taking so long to get back to my own thread, I got disconnected for a while there.
I did get the SA1 to do some funky random stuff by taking an open ended piece of wire from one of the solder points on the jumper you mentioned and touching an end of a resistor. I think it was one of the first resistors after the first IC. It would sound as it was crashing but then it would start a cool random drum sequence. Tha was a god laugh.
Unfortunately I think I may have wasted it now though. I'll need to see if I can fix it somehow so I can try that jumper you mentioned.
The PT20 is being used for my college project at the moment so when i've finished with it there ill see what I can do with it.
If I was able to post up an image of the PT20's circuitry would anyone be able to identify stuff on it I could mess around with? As I said before the circuitry on this is far more complicated than the SA1, which is scarily simple in comparison.
The PT20 only has 7 voices, but it seems it's more designed for using the chord acompaniment as it has a few chord keys to the left.
Anyhows I'll see if I can get a digi cam and upload an image of the circuit.
cheers
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Hi guys, bit late on this post but I've got the Sa-1 that Paul bent.
If it's okay with you Paul I can post a couple of pix of the inside.
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I'd be quite interested in that picture seeing as i've managed to lose the notes for the SA-1 ::)
Post away............ ;)
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Right here we go - photoshop is not one of my strong points so sorry if it's a bit basic ;)
This should be a photo of the chip to the right of the board (looking at Sa-1 with keyboard to the top and speaker to the left)
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Next up is the chip in the centre of the board
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And finally the cut jumper (just like the Paul's other image)
I've also done one of these myself (exact same bends) and although the chips looked different it all worked fine (although the original's deep crash button seems to produce better audio madness)
Hope that all made sense ;)
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Hey! Thanks for those. I got the voltage drop , and i found a connection that howls, but with a potmeter it now works tgether with the voltage drop to make the most unbelievable screaming distortion I mean like 8 bit Jimi Hendrix. next time i open it to incorporate those I will post my bend.
I have to say the SA-1 is ultra amazing, I love it, even sample its sounds without the glitching for my music.
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No problem!
I've a huge soft spot for the Sa-1 as well - the deep crash switch rarely fails to provide some kind of looped, crusty audio madness ;)
look forward to seeing your bend as the more the merrier!
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(http://img102.imageshack.us/img102/9841/sa1screamingbend8vy.jpg) (http://imageshack.us)
Here's my screaming bend, I have a 4700 Log potmeter with a 5600 resistor in parallel, because I had no other potmeters when I did the bend. somewhere around 2 or 3K will probably work best. The bend works well with the Voltage Drop, it's possible to get a screaming distorted sound that still tracks the keyboard.
By the way, tried the Deep Crash F@#%N awesome!
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Lets sit back and watch the price of SA-1's on ebay go through the roof :)
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Hi here, I'm completely new to circuitbending, but a when I visited a friend the other day he showed me his mods to the Casio SA-1 and I was astonished by the magical sounds this little apparatus was able to produce randomly after his treats. Weird melancholical tunes that never were heard before, strange beautiful hypnotizing loops. It's fantastic! This is the thing for me! However, since the SA-1 is not easy to find, I was wondering if anyone can tell me what other machines have the same or even better performance after circuitbending as this little beauty? And what are the risks? Can one ruin his stuff eventually? Or is it always quite safe?
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Most lower number casio SA's i've tried bending will do the same kind of sounds with a voltage drop crash knob installed.
Its always possible to accidently kill something while attempting to circuitbend it but once you have a stable mod installed that has roughly the same effect every time its unlikely that mod will damage anything.
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Most lower number casio SA's i've tried bending will do the same kind of sounds with a voltage drop crash knob installed.
Okay, then I'll buy a shitload of SA's and will start bending. Thanx...
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Most lower number casio SA's i've tried bending will do the same kind of sounds with a voltage drop crash knob installed.
Can I circuitbend the Sa-3 about the same way as the Sa-1? I can get one for cheap and I was wondering if these models are similar? Please let me know, I'm about to buy it and my fingers are itching to do the job!
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I've just bought an SA-1 for my first bending project, even though I've not opened it up yet this thread has been hugely helpful.
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Can I circuitbend the Sa-3 about the same way as the Sa-1?
no idea, seems likely, but if you find out then post the result here ;)
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Can I circuitbend the Sa-3 about the same way as the Sa-1?
no idea, seems likely, but if you find out then post the result here ;)
I certainly will!
By the way, does the Casio MT-750 ring a bell to anyone? Is it circuit-bendable?
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Got my SA-1 today, spent a bit of time poking around and found some interseting bends, one which is a high cut with distortion, thing is it uses the same pin as djsynchro's distortion mod, is there likely to be any problems running two wires from that?l
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thanks to everyone involved in the useful info found here about the lovely sa synths. :)
i've now bent a sa-1, an sa-5 and i'm about to get funky with a sa-65.
they all look like they're based on the same two chips:
oki M6387
AN8053
the sa-65 has the same size circuit board as the mini sized sa's, it just has a big case and larger keyboard! i'd guess all the keyboards in the sa range have the same basic setup with other features added on.
i've found the deep crash on both the sa-1 and sa-5. it's incredible how varied the sounds are that it creates, some of the drones and beats make great samples and loops. for the sa-1 i used the photos in this thread as reference for the pin connections but did a bit more exploring on the sa-5. it looks like the deep crash is triggered by a variety of shorts on the circuit board and can often be triggered by simply soldering up a body contact. it often seems that a very quick short produces the most interesting crash so it's worth trying out different ways to make that trigger and not just throwing in a switch.
infact, i'd suggest body contacts are well used on these keyboards. body resistance seems perfect for some of the buzzy bends which are a bit too extreme if connected with just a switch. if you're looking at the board with the keyboard at the top, try connecting a large body contact to the lower pin of capacitor C5 (c393 in djsynchros pic?) and make up another large contact connected to some/any/all! of the last few pins on the oki6387. i've connected up pins 29 and 30. holding the two contacts (large bolts in my case) produces a lovely buzz which oscilates with the rhythms and sounds of the keyboard. the more you hang on to the bolts, the bigger the buzz. yummy.
the only issue i have with the sa's is the way the batteryies fall out when you open them up! must buy a battery box next time i go down maplins.... ;)
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the sa-65 has the same size circuit board as the mini sized sa's, it just has a big case and larger keyboard! i'd guess all the keyboards in the sa range have the same basic setup with other features added on.
I'd suspect its more of a case of every keyboard being the same but with features disabled for the lower numbered ones as opposed to added on. I remember bending a very surreal SA-40 (you haven't lived until you've experienced its 'magical singer' effects) and discovered a load of extra sounds that weren't accessable from the front panel but could be accessed by shorting disconnected pins on the sound chips.
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the sa-65 has the same size circuit board as the mini sized sa's, it just has a big case and larger keyboard! i'd guess all the keyboards in the sa range have the same basic setup with other features added on.
I'd suspect its more of a case of every keyboard being the same but with features disabled for the lower numbered ones as opposed to added on. I remember bending a very surreal SA-40 (you haven't lived until you've experienced its 'magical singer' effects) and discovered a load of extra sounds that weren't accessable from the front panel but could be accessed by shorting disconnected pins on the sound chips.
nice! so the chip in the little sa's is probably the same one used in the 'nasa sa-2001 alien communicator'.... just with some features disabled and that's where the 'deep crash' feature comes from... well, it's a theory...hehe ;D
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Can I just say thanks to everyone who's posted pictures and tips in here, Modde my SA-1 today and I'm really happy with teh results.
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Can I just say thanks to everyone who's posted pictures and tips in here, Modde my SA-1 today and I'm really happy with teh results.
Welcome to the club! I took my SA-1 to a gig switched it on today and it's screaming without me doindg anyhing.
Maybe the batterries are low, maybe I need to fix it...
[EDIT] opened it - everything seemed alright - replaced the batteries... works as (ab)normal again ;D
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Can I just say thanks to everyone who's posted pictures and tips in here, Modde my SA-1 today and I'm really happy with teh results.
So happy you had to immediately sell it on ebay as 'modified by me for the purpose of selling on'? ;D
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=38071&item=7419197037
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:-[ pwaned.
Need to pay for a holiday, and besides, I enjoy modifying the things more than playing them. Better to let someone else enjoy it rather than it sit gathering dust on a self. It's not like I can't make another one.
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Dear Benders,
Im new to this forum. Yesterday i bought a small Casio SA-1 toy-keyboard. I started looking around at the internet to see if there were any modifications possible. I found this site, and the mods seem really cool. My only
problem is that i have ZERO knowledge and experience with electronics. Its all hard for me to follow all these steps,
but i really want to modify this keyboard!
I can start poking around, use some of the pics posted as a reference. More handy would be a small step-by-step guide about the mods for the SA-1?
Also i didnt noticed anyone talking about a pitch mod for the SA-1. Is it possible??
Thanks in advance!
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I found a pitch mod for the SA-21 which is basically teh same circutry, not sure where it'd be on teh sa-1 though cos it's layed out differently.
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yeah ! me also like to thank everyone who has shared what they've found
on sa1 keyboard....al credits for Crusty Paul, DJ Synchro, Groove Criminals
and all the rest... absolute wicked what you found there! personaly i like best
DJSynchro's howling distortion and-of course- the deep crash; never heard something like that before....amazing
By the way, i guess you all saw these too; http://groups.yahoo.com/group/benders/files/Casio%20SA-1/
includes high pass filter (haven't tried)
so..thanks guys, if i found interesting bents on things, i will share it with
you also in these pages
greetz, nochtanseenspecht
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I found this
http://www.johannesson.dk/SA1.htm
Someone who modified it, you can see the different options. Too bad its in dennish, but we get an idea what the SA1 can do!
nochtanseenpecht, can you tell me alittle bit about what you did (step by step)
Now, i still dont have a clue how to install any of these mods....so any help would be apriciated!
Right now i cut the wire for the voltage drop, so i will "try" to install that mod by myself...
Hope it work O_o
Ok, if someone has some time to tell help a n00b bender, i would greatly apriciate it!!!
Greetz
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Hi sn7ke,
the voltage drop is a good start and quite easy.
i just followed the photographs in this treath...
i think when you do that also, not much can go wrong.
it is a good thing to test the sa1 funktion after each step,
so if it doesn't respond, you know where is the problem.
for the rest i'd say: use a small soldering iron, like 25 watts or so,
anyway not more than 40 watts
heat up the soldering points first (few seconds) then add the
soldering (just a little), if it flows well, it is probably allright
be carefull with heating up components to much,
if you mess it up, better let it cool down before you continue.
soldering on ic legs will be the difficult part, if you're not so experienced
a handy toy is a "soldersucker" (don't know the english name)
if you soldered a bit to much
check also the "How To" pages in this nice forum!
I am not such an experienced bender myself, but of course i like to help
you with what i know so far.just ask.
just do to your SA1 as the other guys explained, and for sure you won't
be disappointed : it's realy amazing! Good Luck!
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Wow! Thanks a lot for your reply. However, my first bending experience wasnt that good so far O_o
I tried installing the voltage drop. Got myself a 1K Potentiometer, and cut the small wire next to the speaker cables.
The potentiometer has 3 points to connect, so i routed one to the middel, and one to the outer right. After failing to wrap the cable ends to each other, i tought that soldering would be a good idea. However the main board of the SA1 doesnt seem to hold any of my solder, and i also burned one end of the wire i cut....Wich end up in a 2MM wire, wich will be hard to connect with a wire now, lol.
Basic question is, is the routing of the wires good? (i know: very basic knowledge this is, but i lack of that!)
I tried it, on the kick ass demo song afcourse, but as soon as i turned the knob of the potentiometer a little bit, the machine just died without making noise. Ok: i admit that there was a little bit of noise, but the volume was sooooo low that no-one ever can notice that. If this is the so superfamous-SA-Lowvoltage-drop....then you guys suck ..lol
Next to that, how to install the other mods and what do they do? And are there some interesting body contact points??
Thanks in advance,
If someone likes to help, you can add me under sandervw_@hotmail.com in MSN messsenger!
Ok bye!
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Ah, another question regarding safety
While modding and testing, should i use the 6V adapter, or mess around until i got the batteries connected (since they are in the back case wich is crewed of.....
Im a bit scared powering my SA-1 with a 6V adapter pluged into a 220V channel...O_O
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okay: there is no problem testing with an adaptor while sa1 is open,
it is not dangerous, but better take it out while soldering i guess.
perhaps the value of your pot is to high, i forget what i used, but
something like 500 K should work. The way you connected should work to,
but it is better to do like this : lay it down in front of you with the shaft pointing upwards, the 3 legs point to you. one connection goes to the
left and middle one, the other to the right, now when testing turn it
counterclockwise and you should hear a kind of saw wave, wich
modulates if you turn it more. the keys don't function when you do this,
but thats normal
if you got that working, i higly recommend DJSynchro's distortion bent
couse its real nice in combination with the voltage drop
an absolute must is the deep crash (pushbutton), but if you do that,
make also a reset button (break contact) in line with (before) the
voltage drop
the low pass filter is good to keep your partner happy while deepcrashing
the synth swich is also fun, but only combined with the voltage drop
(maybe nice as body contacts instead of switch ?)
body contacts you will discover by touching the cicuit board while it is on,
don't worry: 6 volt won't kill you
i recomment you practice soldering first on an old circuit board
try to make loose some usable parts etc until you get the feeling
of soldering. don't worry, you will learn
And get yourself a cheap multimeter (quickly see the value of a resistor,
check howmuch volt comes out your adaptor for real etc.)
good luck !
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Ok, thanks a lot! I will try those mods, hope they work. Deep crash seems verrry interesting.
I think a set of various Potentiometers and some wires/screws will be all i need?
And, do i just need to drill some holes in the casing to put the meters/screws in?
seems ok! Will try! and uhm...if im stuck i will be here
Oh btw for the Potentiometer i cheked it:
If you connect only the middle with one wire, and the end with one wire is used for volume control
Variable control is the middle+left end to the first wire and right end to the other..
I love wiki..
Bye!
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Woah.... zero mods installed, and now my Casio SA1 isnt working anymore?!
What could be wrong!
I cut the jumper wire for the volt drop, but when i connect em again and feed the casio with the adapter, i only hear a low bubbling noise. Eventually i will hear a crash sometimes. Normally i would hear 3 buttons pressed (somehow they are stuck on the board or whatever, cant release em but will not be hard i guess ) and then i could use the casio.
Ehrr...i tought maybe the ON switch wasnt connected so good, but i screwed the whole board to the casing, and everything looked steady and fitted...
What could i have done wrong, is the casio R.I.P...? lol
Bye!
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hmm strange...a multimeter would be helpful for you...
hope you will fix it somehow..it's a real nice little bastard
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If you've tried to instal teh deep crash mod, it's probably worth checking that you've not managed to accidentally solder up two pins, I did this andthe keyboard stopped working, but it was solved easily enough by filing out the bits of solder.
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Well, i can only say i cut the jumper for the voltage crash. After that i screwed it of the top casing so i could chek the back, while the jumpers were linked again with two wires solderd.
After that, the Casio started tripping, making no sounds, and sometimes a crash sound. My adapter went dead after that, and on batteries it doesnt work anymore. I only rememberd poking around with a piece of metal at the solder points, but thats about it, i didnt forced anything, just gently touched
Is there a SA rerscue team? damn! i think its dead!
(and thanks no:signal, but i wasnt even up to that point yet! l)
I tried other adapters...but no signal or sparks or anything, could the power-routing or whatever be broke in the casio?
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Update of the problem: (sorry i feel like bombing this topic!)
WHen i switch the CASIO SA 1 , and put my ear close to the speaker i hear a small, low ,buzing sound...
Thats about all the sound it makes...even when i press the keys. Nothing is bend yet.
Mmm...what could be broke
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I've thought of a possible cause of the problem, when you soldered the pot across the wire, it's possible that you managed to move it out of contact with the circuit board and in doing so created a dry joint. Poke around with teh soldering iron and move things around when the solder's liquid.
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Hi guys,
After leaving it alone for a couple of days, i managed to get it all working again. Somehow i had to solder a wire from the small chip to the bigger one, but it works again so there you go.
I got the voltage drop working with a 470 ohm pod, i also tried it wirh a 1k pot (works)
however with both i can only turn the knob a few millimiter before the voltage already is too low. Afcrourse it makes cool crashing sounds, but you need to turn the knob with great precise and care. Not good for live work etc. On what does it depent? Lower /higher Ohm? Thanks to my lack of knowledge i have no clue!
(btw, bougt an Sa-5 today. First planning to kill/mod my SA-1. If i can cross out the "Kill" word, than my SA-5 will be bend :D Bending is cool!)
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Lower is better for mor control.
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Hi there!
Small update: My casio is up & running again, and i even installed a couple of mods already. It looked harder then it actually was!
I still have some small questions that I hope some of you can answer!
This guy: http://www.johannesson.dk/SA1_eng.htm
has a crash/glitch button, wich he has a second meter that controls the first one. You can control the intensity of the crash.
This seems pretty wicked, but how is it done? He is using the Deep crash function
Can you solder a Potmeter between the Push to connect deep crash button? (wich let you control the intensity of the crash? – and if yes: what value?) Or is it done in another way
Another question goes about body contact points, I found a few buzzing points on the SA-1. When touching the soulder points directly, it works. But it doesn’t work anymore after connecting a wire and some metal object. Even touching the wire doesn’t make it buz. I have this feeling Im doing something stupid.. Directions are welcome!
Im also searching for points to create a dissortion switch. So far I only found a disortion bodypoint. The Casio in the link above has a dissortion switch
Third: Bought a Casio SA-5. Can you do different/exclusive mods to this, that differ from the SA-1? Hope so!
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I did something similar to my sa-21 to get the deep crash working, you need to solder a really low value pot between the push button and the chip, and buy low I mean low 1K or less.
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Ok , i noticed even 470 Ohm is a little bit too heavy for the crashes, you can only turn it up a quarter before the actuall crash comes....Im going to get some nice parts today, and continue bending!
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Try combining resistors in parallel, if i remeber my a level physics correctly that will reduce the overall resistance.
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Heh, ok how to do that, what is parallel? i still dont get all these technical stuff, but im defenitly willing to learn!
Btw: Casio SA-1 is finally done :D now i only need some spray paint
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i was bending an sa-5 yesterday. the voltage drop as seen in this thread for the sa-1 doesn't seem to work. i cut the wire (seemed to look the same as the sa-1) but it made no difference to the synth! it just kept on working!
hmmm.... most odd.
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Chek http://www.natemc.com/news/?p=203 for a bend Sa-5 with some pics of the points etc.
What value pot did you use? I noticed 200 OHm works the best, probably lower if you wish to turn the know more.
If you used 1K or higher probably it will kill the voltage imideatly, you wont even hear a thing.
Connect 1 point to the right, and the other point to the TWO other pins left on the pot.
Ok hope this helped
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thanks for the sa-5 link. i'll be impressed to see something i've yet to find though. think i've now spent far too long fiddling with the insides of the sa's i have... hhehehehe. ;)
my voltage drop attempt didnt involve a pot. i cut the wire on the board, which should result in the keyboard showing no life, and nothing happened. the synth still worked fine! so things are a little different on the sa-5 than the sa-1.
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O_o you cut the power-wire and it still works??!!!
=_=?!! sure you cut the right wire then?
lol. Well...anyway! I got an SA-5 too. Do you mind tell me a bit about the mods you did so far? Maybe it can help me when i start bending the SA-5 this week!
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I got the voltage drop working with a 470 ohm pod, i also tried it wirh a 1k pot (works)
however with both i can only turn the knob a few millimiter before the voltage already is too low.
Hi sn7ke
Using a multimeter and a potentiometer i've worked out that i need about 80-200ohms hooked into the power supply to give a reliable voltage crash on my SA-20.
This is how to turn any 0-whatever pot into an A-B pot (in this case 80-200ohm)
the mini-circuit consists of 2 pre set resisters and a pot as shown below
----------Resister A----Pot------------------
\ /
\-------Resister B---------/
Resister B should be your top ohmage so 200ohm.
Use the formula A = RB/B-R to get the value of the other resister. (this assumes that the pot goes down to 0ohm)
for me R=80, B=200 so
A = 16000/120 = 133 ohms
now we have an idea of the resister's values, check the top resistance. P is the pot value, 100k in this case.
Top R = B(A+P)/(A+B+P) = 200(110+100000)/(110+200+100000)=199ohms
so solder some resisters together and we have an 80ohm-200ohm pot!
I generally use preset pots for A & B so that i can tweak, but this is how you get the starting values.
BTW Use a logarithmic pot with this technique to get a linear scale, linear pots creates a inverse log scaling effect for those who are interested :)
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Have somebody a picture of how they done the voltage drop on a SA-65??
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Hi sn7ke
Using a multimeter and a potentiometer i've worked out that i need about 80-200ohms hooked into the power supply to give a reliable voltage crash on my SA-20.
This is how to turn any 0-whatever pot into an A-B pot (in this case 80-200ohm)
the mini-circuit consists of 2 pre set resisters and a pot as shown below
----------Resister A----Pot------------------
\ /
\-------Resister B---------/
Resister B should be your top ohmage so 200ohm.
Use the formula A = RB/B-R to get the value of the other resister. (this assumes that the pot goes down to 0ohm)
for me R=80, B=200 so
A = 16000/120 = 133 ohms
now we have an idea of the resister's values, check the top resistance. P is the pot value, 100k in this case.
Top R = B(A+P)/(A+B+P) = 200(110+100000)/(110+200+100000)=199ohms
so solder some resisters together and we have an 80ohm-200ohm pot!
I generally use preset pots for A & B so that i can tweak, but this is how you get the starting values.
BTW Use a logarithmic pot with this technique to get a linear scale, linear pots creates a inverse log scaling effect for those who are interested :)
good thinking. and good description of applying. thanks-
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OK here's the deal: (SA-1) Just found this:
In series with the deep crash button solder something like 100 ohm pot.
I didn't have one, so I got 1k with a 100 ohm resistor in parallel=110 ohms I think
Now the Glitchcontrol works in conjuction with the voltage drop!
Turn it up a little, press the deep crash, nothing happens. Now turn up voltage drop a little, and the SA-1 will start crashing. (Or just turn the Glichcontrol up further)
It really expands the amounts of sounds you get. Also without this trim a lot of the times the crashes will be silent. Not with this bend, you can set it so you get a good crash all the time. Also, at some settings now it will glitch when you press the deep crash button, but recover when you let go of it.
I say essential SA-1 bend, go for it.
Have fun!
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thanks ! nice one. i will try it out soon. i'm also still a fan of your sa1 distortion mod !
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This is the essential killer one!!!
Let there be no doubt: You HAVE to install this one it improves the SA-1's glitchability tenfold.
For example, depending on the knob settings and the selected preset, now sometimes I get non stop glitching,
and pressing the deep crash button keeps changing it (Instead of crashing the SA silent)
Let me know if you get it going & how you like it!
:D
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... sounds great but I'm having trouble with the voltage crash on my SA-20 (similar to a SA-21). I'm using a 470 ohm pot which is too sensitive. I've heard it works best with 200 ohm pot (or less). Is the voltage crash worth having?
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Is the pope a catholic? You GOT to have the voltage crash. I used to have 1k, now solderd a 500 ohm in parallel so that's 500 ohms, works fine. try 200 (or just try wiring some resistors in parallel.
You gotta git da voltage dawn boyyyy! :)
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i've also found the voltage crash to be quite sensitive and prone to just turning off rather than crash in a nice way.
i reckon the way forward could be one of those small preset pots that you set and leave. set it to a nice crash setting and then it'll do the same thing every time. could even be triggered by a switch.
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Can I politely disagree? The Voltage drop, Scream & Deep Crash trim pots I have all work together.
They all have small ranges where the glitching will be changing so you really need to have them on pots.
It's true that you don't really get a nice long smooth run where the glitching will fade in, but hey it's not an analogue volume control or something, it's a short circuit.
I have just built another SA-1 as a present for someone. It has a "version 1" board, made in Japan (Mine's version 3 made in Korea) 220 Ohm for Deep Crash trim, 2200 for Scream, 500 ohm (1k with 1k resistor in parallel) for voltage drop. Works great with fresh batteries. Still fiddly to operate though :-)
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I've calculated that a 470 Ohm pot and a 1400 Ohm trimmer should work nicely for the voltage drop crash but... they have to run in parallel... so what does that mean, one wire split halfway up with a pot, trimmer in each then rejoin? I used two separate wires for each of the variable resistors but it didn't work as I expected it to. Am I going about this the wrong way?
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@ djsynchro ; i followed your instructions (100 ohm pot in line with the deep crash) and you're right,
it is a must have !! my sa1 keeps crashing in a nice way at a certain setting. nice one , thanks !
most loops i've heard before, but i dont need the reset knob nomore.
btw, i just opened a realistic concertmate 970 : it seems to puke out the same loops as the sa1 if i crash it (?)
but in stereo with chorus ! (the soundchip is named m6387-08)
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I've calculated that a 470 Ohm pot and a 1400 Ohm trimmer should work nicely for the voltage drop crash but... they have to run in parallel... so what does that mean
One wire to the centre connection of the pot, one wire to one of the outer connections (This is clockwise/anticlockwise, I have mine so clockwise increases resistance -->> and brings on the crash)
Resistor from center to the same outer connection as the wire. Now some electrictity runs thru the pot, some thru the resistor-->> Parallel! ;)
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@ djsynchro ; i followed your instructions (100 ohm pot in line with the deep crash) and you're right,
it is a must have !!
Told you! Glad you like it :)
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(http://static.flickr.com/99/278540350_8ebb195a85.jpg?v=0)
An SA-1 built as a present so I decided to decorate it. It's so ugly that it's pretty,
I hated it at first but it really grew on me. Will be hard to let go of, glitches better than mine too.
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The paint job looks great... bends good too huh?
I included a voltage drop crash on my SA-20... works best when the keyboard has been left on a while. I've also (very badly) wired up a Casio SA-8... works ok but it looks terrible... wires everywhere and the case doesn't shut. I really detest soldering!
BTW... what other keyboards apart from the Casio SA series generate random chance compositions?
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I really detest soldering!
You may have chosen the wrong hobby there then ;)
BTW... what other keyboards apart from the Casio SA series generate random chance compositions?
If i recall correctly theres a whole series of Realistic Concertmate keyboards that appear to be direct rip off's / rebadged casio SA's, but they seem to be built with cheaper circuits and components. Never tried bending any of them though.
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BTW... what other keyboards apart from the Casio SA series generate random chance compositions?
The Casio MT-140/240 do some pretty far out stuff, though slightly different from the SA range. I can't recommend them enough! : )
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Yes, the Casio MT-140 is featured in Ghazala's book... looks a bit old fashioned though!
I just picked up a Yamaha PSS-30 but I've found nothing interesting with it.
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I've posted about a yamahaPSS190 in a separate topic today, and in it I have put what I have done to an SA-8...
I had not found any info on bending these so just tried myself to find some sounds......I think it is basically like the SA-1/2/5 (please correct me if I am wrong though) but laid out slightly different...but the elements are not far off...
Question is, would it be possible to add these cool bends I have seen in this topic?
I hope so because if it adds another element to what it can already do.......Its going to be a beast!!!
cheers.
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ive been bending an sa1 as is described. i was putting in the deep chrash and the whole unit just stopped working, i get nothing coming form the speakers at all not even hiss. it was working fine up until this point. ive taken the deep chrash out and made sure there is no solder connecting any pins and i still have nothing.
im wondering if ive fried the chip how can i tell? would the unit not even switch on if the chip had gone, surely i would get some hissing.
does anyone have any ideas what ive done wrong? i really hope its not dead it was was starting to sound good >:(
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it's impossible to tell from your description what has gone wrong with your sa..
..but, i can say that i've bent quite a few of them and have never managed to fry any due to modding up the crash functions, or any other bends. they seem rock solid...
so, i'd make sure you've covered all the possibles... power supply/batteries, solder touching pins, loose wires etc before deciding if your little friend is dead...
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make sure you check all the obvious things, like battery connections & batteries etc!
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cheers for the help i figured it out the on switch wasnt connecting with the board because of a cable tie id used.
ive installed all the bends on this forum and it sounds wicked so thanks to everyone whos posted ;D ;D
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Thanks so much to everyone who has posted on this board! I've been bending for about a year and had somehow never heard of the voltage drop mod. What a great technique!
My SA-1, which I hadn't had much luck with before, is now in top form.
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Here's a must have effect for any SA-1 - I just tried it today and it sounds awsome.
First of all you must have done the following mods (all have been discussed prior on this thread):
a) the sa-1 must have the voltage mod crash, or some other bend that causes the machine to crash.
b) the 'dj synchro distortion mod' should be installed.
If you have a SA-1 with both these mods then I urge you to build a LFO with a 555 and DIY Vactrol and then run the (+) side of SA-1's audio through the light dependant resistor side of the vactrol before connecting it to the speaker or jack. The 555 timer circuit will need to attached to part of the keyboard somewhere to gain its power, preferebly configured so you can turn it on and off with the keyboard's power switch.
When this is set correctly the DIY LFO will act as a 'gapper' effect on the audio and you can change the rate by the pot. Just playing the piano or synth waves sounds good. However what really sounds amazing is if you crash the keyboard so you have white noise or some thing similar - you can then sweep the noise with the distortion mod whilst simultaniously lowering the rate of the gapper, then when it's most distorted (and missing the high frequencies) you can decrease the distortion whilst increasing the rate of the gapper. It sounds very cool - try it! :)
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hiya i am a new user to this site but have been bending stuff for around 3 of your earth years!!!!
but seriously the pt20 (concertmate 300) is possible to bend i had one for a whille and gave up but went back to it after a few weeks ans now it has a tone control of an octave either way and have set this up on a pot. this increases the tempo of the drums and because you can slow the drums with the tempo buttons still you get some almost broken slow glitch noises from the drums. the pot also controls pitch for an effect just like a theremin and with the audio out can be effected. very stable and working. add to this the dostortion switch off/on this glitch effects the drums and makes for some very interesting backbeats. also this controls the theremin sound thus giving a built in distortion pedal great. will post some pickies soon. cheers. :D :D
ps am also looking into putting circuit bent pedals into ALA matt belamy but circuit bended!!!
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Hi all,
I have been following this thread over the last year and recently I finally dug out my SA-20 from the pile of junk for some bending action. Thanks to all the useful tips here I've got the deep crash and voltage drop bends working fine. I have been having lots of fun, so thanks a million for all the great documentation.
However, I have been poking around trying to find the screaming bend (see DJsynchro's post) without much success. I would like to ask if anyone:
a) Has found this on an SA-20?
b) Or, who knows roughly what resistor the 3k pot is connected to? (so I can narrow down my choices on the PCB)
Thanks in advance for any help
Dave mK
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If you have a SA-1 with both these mods then I urge you to build a LFO with a 555 and DIY Vactrol and then run the (+) side of SA-1's audio through the light dependant resistor side of the vactrol before connecting it to the speaker or jack
So one of the legs from the LDR would go to the + wire and the other would go to the speaker?
Fussing around with my SA-1, trying unsuccesfully to remember the specifics of the above technique, I found that if you put the LDR across the two terminals on the djsynchro noise pot you can get a pulse effect. The flash of the LED triggers the distortion.
Probably not worth building a new oscillator for, but if you have one just kicking around it opens up another option.
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(http://www.circuitbenders.co.uk/IMAGES/SA-1_pcb_top1.jpg)
That jumper wire just to the right of the word SPEAKER is the one i'm talking about. Cut that and wire a pot accorss the gap.
I can't remember where that image came from but its from some circuitbending site so if it belongs to someone who recognises it, let me know and i'll credit it to you.
i would like to try this. which value potentiometer should be wired here?
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i saw a photo of a 500k pot for POWERCRASH wired in a different place: the contact for the power supply jack.
which place is best?
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Its exactly the same thing, if i recall correctly both the battery power and the jack power go through that jumper.
I know for a fact theres some discussion either on this thread or elsewhere on here about pot values, the search function is your friend.
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this is good stuff! ;-)
so, is that pretty standard on most casio boards? if i see a jumper to the right of the power jack?
also, what about polarity? does it matter which side goes to which on the jumper?
(i admit i am not as intuitive about electronics as the status quo on here...but i am here to learn...dumb questions are better than dumb mistakes. thanks for your patience.)
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As far as i know you'll only see that jumper on an SA1 although i could be wrong and you might see it on other. If you're putting in a voltage drop crash pot i'd always wire it on the positive side of the supply. It doesn't matter which way round you wire a pot if its wired in line with the positive supply. The only difference it'd make is which way you have to turn the pot.
It shouldb't be that hard to trace the power rails on any cheap keyboard, just follow the circuit board traces from the power jack and/or the battery compartment until it gets to a component. Wiring in a pot before that point should probably give you a variable voltage input.
Getting hold of a multimeter might be helpful for tracking down the positive and negative rails if you have any difficulty.
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i saw a photo of a 500k pot for POWERCRASH wired in a different place: the contact for the power supply jack.
A 500K pot will be about a zillion times too big. Try a 500 ohm pot.
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hi guys
I found an interesting "decay" control for my SA-1
it's possible create very cool sounds using this in combination with a distortion pot
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Hi guys
I am new to bending and the whole world of electronics in general and trying out a few SA-1s, following some of the great diagrams and tips here. Haven't had much luck yet, and just wanted to see if there were any general tips on how to diagnose problems. I appear to have killed one and the other two were bought 'untested and as seen'. I can get a few notes out of one before it, almost literally, coughs, chokes and dies. I can keep doing this by turning it off and on again, though it won't do it every time, but I can't get it to play more than a few notes. I haven't added any mods except add a line-out jack and battery pack. It doesn't look that great inside, and the battery coil is rusty.
Also, after the keys stop working, I can get various low hums and crackles by touching screwdrivers on the chip pins corresponding to glitch and other bends seen in the diagrams, so it's clearly still live and responsive in some way, but not providing any of the wonderful madness I got from the same glitch connections on the other one before it stopped working, so I don't know what the problem is with this one.
As I said, I'm trying to learn how everything works from scratch, so any suggestions for trouble shooting, much appreciated.
Cheers