Circuitbenders Forum
Circuitbenders Forum => Circuitbending discussion => Synths & Samplers => Topic started by: marmora on May 06, 2010, 04:48:35 AM
-
Hey guys,
Looking for some bends for my Alaron my song maker keyboard. I've poked around a bit and haven't found anything.
Mine looks way different than the one at Table Hooters:
http://weltenschule.de/TableHooters/MySongMaker.html (http://weltenschule.de/TableHooters/MySongMaker.html)
Mine looks like this on the outside (but a different color):
http://www.flickr.com/photos/extradrowsyformula/3517473307/# (http://www.flickr.com/photos/extradrowsyformula/3517473307/#)
I found a video on youtube of a bent one, so there's something in there, but where....?
-
This is one of those ones that always seems to turn up on ebay with a dozen or so really weak mods one it, called a 'super psycho digital black hole noise box' or somethng.
I know theres a pitch resistor in there, at least there was on the tablehooters version i bent about 8 years ago. At a guess its going to be one of those ones on the back of the board with the black blob on it. Lick your finger tip and poke around there while its making a noise.
-
Thanks, I think I just needed some encouragement. :)
I had some time to poke around and found some things:
Licking my finger and rubbing it between the resistor and electrolytic cap on the chip board changed the speed/pitch. It sounded good, but when I tried to recreate it with a pot, the unit wouldn't even produce sound.
Wiring a pot as a voltage divider with the middle lug to the same spot on the board gave me another type of speed/pitch change. I had a feeling I could do that one, I was just looking for other things first. ;D
Adding a jumper from the left side of C14 (the cap in the pic with the longest legs) to the same spot on the chip board made for scrambled sound. Would probably be good with a momentary switch. If a drum beat is going and you make this connection, the beat will continue as soon as you disconnect it. I tried a pot and got some more pitch/speed change as well.
Adding a jumper from the jumper right in the middle of the last picture, to a lot of the pins from the chip create background drones. I think hooking it up to pins 10 and 11 (counting from the left) sounded good to me.
Adding another jumper from that same jumper I just mentioned to pins 1 or 2 (again from the left) made the drum beats and animal sounds louder and more clear.
Any other things I find, I'll update here.
-
You should be able to just pull one of theose resistors out and replace it with a pot, although you might have to add a lower value resistor in line to stop it from crashing.
If its anything like the one on the tablehooters site you'll probably be able to do a good voltage drop crash on this thing. Do a search on here or find the really long Casio SA thread for more details.
-
The voltage drop is really nice on this!
Found some more noise/drones as well.
I do have one problem though: I added an output jack and the volume is very low. I've had a problem with the volume being too high/distorted with other keyboards and I fixed it, but I'm not sure how to remedy this.
Actually, the volume seems to start at the right level and then go down until it stays at another level...internal speaker works fine. Any ideas?
When things gradually change I think capacitor, but I haven't dug too deep into this since it would mean unscrewing another pcb.
-
I was gonna post suggesting that you try a resistor connecting the speaker positive and negative, but I've got the same one here so decided to quickly open it up to check. :)
A 1k resistor does the trick on this one, though sometimes you need an 8ohm resistor instead to act as a dummy load where the speaker would normally be - you can check the rating on the back of the speaker but I think most toys I've opened up have had 8ohm speakers.
Also looks like we've found 3 colour schemes so far - mine's orange base with green handles.
-
Thanks for the reply.
I might have tried a higher value as well, but I wasn't taking notes so I can't say for sure. I did find another bend or two and will share them when I get those notes together.
Unfortunately, I wound up frying this keyboard. I've seen a couple more since I first had mine, so maybe I'll pick another up one day.
If I recall, the one I saw was green with purple handles (or vice versa).
Have you noticed how screwed up the PCB is inside? The parts don't match the component overlay at all. There are tons of unused holes throughout. Must have been a lot of work figuring that out.
-
Have you noticed how screwed up the PCB is inside? The parts don't match the component overlay at all. There are tons of unused holes throughout. Must have been a lot of work figuring that out.
Thats probably because that company use the same PCB for about 20 different toys with similar circuits. I'd imagine they save a lot of money that way.
-
True, though this one could be the weirdest I've seen yet - haven't encountered wires trailing out of the LM386 amp socket before!
-
Here's a quick pictorial guide to some of the bends. There are a couple more in there I'm sure. I didn't include the pitch bend since I wrote about that in an earlier post.
http://experimentalistsanonymous.com/diy/Schematics/Circuit%20Bending%20and%20Modifications/Alaron%20MySongMaker.jpg (http://experimentalistsanonymous.com/diy/Schematics/Circuit%20Bending%20and%20Modifications/Alaron%20MySongMaker.jpg)
-
Mine was a quarter step sharp. On the little integrated circuit board, R42 had a jumper and R41 had a 10 ohm resistor. Replacing the R41 resistor with a jumper provided a slight flattening. Replacing the R42 jumper with 70 ohms resistance brought it exactly into tune.
Having accomplished my objective, I didn't play around any further, but my guess is that R42 lowers the pitch and R41 increases pitch.
Just FYI in case anyone else finds themselves playing around with one of these little gems.