Alesis SR-16 SMD Version

[slx]

Hello there,

i do have an Alesis SR-16 and found some good infos on the web to bent it. But after opening it up, it looks totally different than the one i found infos about. It seems i have a newer version with smd chips. Does anybody know if this thing is still bentable? What are the ROM chips or pins? I am not very experienced bender so this power supply thing makes me nervous ... any hints for that too?

Thanks,
slx

[Circuitbenders]

Theres an SMD version? I wonder when they updated it? Does yours have a date on the circuitboard?

I guess its probably the same circuit. The sound ROM or ROM's will probably still be some of the biggest chips on the board. I guess its time to start searching for datasheets until you find a ROM chip.

Don't worry about bending something with an external power supply. The only time you's really have to worry might be if the power supply was internal and you might have potentially lethal voltages exposed.

[slx]

Thanx for your reply and tips.

This evening i trusted that unknown virtual voice, your voice and just shortcut some tiny smds with an isolated wire and i found the ROM chip. I am still alive  

The writing on the chip is poorly readable. Here is what i can read ... ST M29 maybe W ?? then maybe DP ?

The date on the board says 10 NOV 2009.

Regards,
slx

[Circuitbenders]

if you are going to use a patchbay or similar, i would advise finding which pins are the power rails and ground on the sound ROM, and definitely not using both of them. Shorting other pins to ground should be fine and should produce some interesting results, and probably the same for other pins to +5v, but you don't want to be accidently shorting the power pins to ground.

If you can't work out which pins you are looking for, get a magnifying glass and read the code on the chip so you can find a datasheet.

[slx]

that was addictive. unfortunately, i think i killed her. or maybe not me, but something. i didn't even touched her at that moment, just listened to the beautiful rhythmic noise and bing ... gone. I think i fell in love.

[adamduke]

I picked up one of these recently, opened it up and yup - all SMD.  Noticed two stickers inside on various chips: one said 2001 and one said 2004.

Two chips on the left of the board are the ones you want


I'll post the links to the IC datasheets when I'm on my other computer, but I ended up with 32 points of note, 4 which seem to be the most common.  You need to add a 1K res to each of the points I also found - straight connecting just freezes it.

I definitely don't have the hands of a surgeon and soldering SMD chips definitely seems to be the most stressful thing I choose to do with my free time!

[adamduke]

IC's

http://www.ic-on-line.cn/view_download.php?id=1199166&file=0112\bs62lv256sip55_1182373.pdf

http://www.ic-on-line.cn/view_download.php?id=1043181&file=0004\ht27c512_26307.pdf

[adamduke]

I really want to install a pitch mod on this buuuut...I don't see a crystal, none of the obvious resistors seem to respond to jumping and more importantly,...I have never done an LTC mod before(!).  What am I looking for exactly?  I'm guessing that I'm looking for a clock out from a main CPU chip?  Like maybe the square guy in the center with Alesis on it?  Once I find that, the question becomes power as I thought the LTC ran from +5V and this is mains power.  Am I totally off base?

[Circuitbenders]

I can't see a crystal or resonator on the picture, but its not really very clear. Have you got a better resolution copy? The crystal might be e a small metal can, like a small thin eleoctro;ytic cap on its side and without a label.

There will be a 5v power rail in the SR16 somewhere. Most circuits will run any logic chips or microcontrollers on 5v. Try the top right pin of those 14 or 16 pin chips, or one of the pins of that thing that looks like a voltage regulator just under the big filter caps on the top left.

[adamduke]

Hey you lot...
Wanted to mention that the IC chips I posted above seem to be involved mostly in sound/pattern swapping.  The 44 pin IC to the right with the white sticker is the chip with all the sound mangling.

Also, as I dive in to finish this, is the silver squarish lump at the bottom (near those two 14 pin IC's) the clock that I'm looking for?  It only says '8.00M' on it and I have no idea what the pin out would be or where I could look it up.. I will upload a closer photo to imgur and post it

[Circuitbenders]

I've done an LTC pitch control on a SMD SR16, but its a little crackly when you turn the knob. It works fine if you just move it and leave though.

Post a better picture and i'll see if i can point out the ceramic resonator or crystal. i don't recall which it is.

[adamduke]

...is that the guy?

Not awesome news about the crackling... still a useful mod to me however 

[Circuitbenders]

Thats the one, although now i see it i recall how unbelievably difficult it was to remove it from the board. I ended up having to shatter it, and then take off the pieces by heating it with a miniature heat gun  Not fun at all.