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casio SA-2

Started by brewmachine, November 04, 2008, 02:53:20 AM

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brewmachine

Just scored one for a few quid the other day, already had it in bits and found a few glitches and the secret samplebanks, etc... ive checked em out on youtube and seen one or 2 with an immense overdrive and filter like bend, just wondering if anyone knows how i can manage this as ive been playin around for ages now and how found nowt.

also whats the crack with the low power hack?

cheers
brew

Circuitbenders

The second longest thread on this forum is about casio SA machines, the longest being about Yamaha PSS/PSR's

We have supplied you with a wonderful forum search feature for these exact occasions ;)
i am not paid to listen to this drivel, you are a terminal fool

brewmachine

 ::) oh yeah,
I actually found that thread but didn't see it had more than 1 page
textbook error, hehe

cheers
brew

brewmachine

hey,

ive looked through that post and its pointed me in the right direction, found a little distortion but nothing as dirty as what i was expecting, except it doesnt work with a pot as described in the other thread (possibly due to differences between the sa-1 and the sa-2)

I also tried the voltage crash but when i cut the jumper the keyboard still worked fine, Ive read on casper electronics that the voltage crash isnt available on the sa-2... is this true or is there just another way to go about it?

ive already found the deep crashes (theres loads of points that trigger it) but yet again pots dont seem to adjust the depth of the glitch...

ill keep poking about but sum further guidence would be much apprectiated

ill try and post sum scans of what ive found so far if anyone is interested?

brew

argossummergiftguide

Hey guys, newbie here,
I've been bending my Casio SA-2 and getting to grips with a few of the bends on here, added the volume, drum pads out, I added a power crash out. Since then, something has happened, my keyboard only plays at a really low volume through the speaker and aux out even when i disconnected the power crash mod and made sure nothing is short circuiting... reckon I've blown the op amp, it is possible that I hooked it up to 9v adapter by accident (even worse, I may have even reversed the polarity)? how would i find out if I've blown it? any suggestions, could I have blown something simple to replace?

Circuitbenders

Whats the opamp in the SA2? I'm not sure theres much else that could actually go wrong
i am not paid to listen to this drivel, you are a terminal fool

argossummergiftguide

The opamp is an an8053n. I'm not sure it's in production any more. You reckon this could be what's blown as the volume is so quiet? also when engaging the power crash mod, the unit just cuts out after the pot reaches about an eighth of the way round like it's not recieving enough power. Would I be able to replace the old opamp with a modern equivalent with the same/similar specs?

thanks for replying so quickly by the way!

Circuitbenders

I don't have a SA2 to look at, but from the couple of pictures of the board i've seen on the net, it doesn't look like theres a lot else that can really go wrong.

Have you got a multimeter? If you have, i guess you should be seeing the supply voltage on pin 16, and from the look of it you should see 5v on pin 13. There seems to be some kind of 5v regulator inside the AN8053 which might explain power problems if its knackered, but without a schematic its a little tricky to know what its meant to be doing

You can get a new one from cricklewood at http://www.cricklewoodelectronics.com/AN8053.html or aliexpress from china at http://www.aliexpress.com/item/AN8053N-AN8053/1638383351.html?spm=0.0.0.0.9cctBt but other than that you'd probably end up paying around £10 for one on ebay, so you might as well just get another SA2
I don't know of a modern equivalent that would just drop in.
i am not paid to listen to this drivel, you are a terminal fool

argossummergiftguide

Thanks so much, Yeah, I do see 5v across those pins, did a bit of a google and got the datasheet on the an8053n and checked that out but that's about as far as my common sense gets me with electronics, the link between input and ground is not internally shorted, I think... Now I just need to decide whether to spend £10 on fast UK delivery or wait ages from china... or buy a new 2nd hand SA-2... bugger

argossummergiftguide

Wow, crinklewood based in london and far less than ebay, nice one! Thanks for the tip, I'm gonna post some pics and vids of my SA-2 when I'm finished, nice to know this site is really supportive!

argossummergiftguide

hmm, so I swapped the opamp for a new one, still really low volume, all the sounds work, not sure what's up, I removed all of my bends and the sound out of the internal speaker is still really low, when I plugged the unit in before removing my bends, all I get is buzz, not even any sound... So Buzz from the audio out, and really low volume from the speaker... I'm going to try to test everything check all of the parts work...

Any suggestions? I know it's not the power switch. Could the buzz indicate a grounding issue? If so, how? I've removed all of my bends. Could a trace be broken or damaged, causing loads of resistanceor some electricity not making it back to ground...


argossummergiftguide

Oh and there's loads of digital noise through the little speaker if i listen carefully, possibly the same as the buzz when plugged into aux out