Bending A 505 (Many Questions)

[Jaicen]

Ok, i've just got myself a TR-505 which i'm planning to bend.
I don't really care for the stock sounds, i'm looking for something a little grittier and gnarly, more industrial.
I've found this site: http://burnkit2600.machinenoise.com/505_mods.html
which has some good tips for what to bend etc, but since this is my first bend, i'd like some guidance.
I'd like to use switches for the bends rather than a patch bay, as I know i'd just lose my leads and I want it to look neat ( I just want it to sound messy )I want to have lots of realtime control using pots as well.
So, which of the bends will I get the most mileage from using switches and pots?? I know it's a case of me sitting an fiddling, since that's what this is all about, but some hints would be nice
I'd also like to know if there's a way to change the sample rate to pitch the individual instruments, since the 505 has no stock option for that, though it does already have the 5 outs installed (not by me).
Ok, one last question: What can I do that's guaranteed to destroy my 505! I really don't want to waste a nice old machine like this with stupdity
Thanks for your help guys,
*j

[Circuitbenders]

I think the only way you are going to be able to change the pitch  of the sounds in the 505 is with a lot of extra electronics probably involving a 555 oscillator / timer chip or similar. I've heard of people doing it but it really wouldn't be easy.

There are no decent bends in the 505 that i've ever found that can be controlled with variable knobs. Its more a case of direct shorts between chip pins that are either on or off with no variation. TR505's with knobs are probably using them to control individual sound levels, there are details on that burnkit link.

The main chip you want to be messing with is the sound ROM chip. This is the one that says usually says Roland on it to the right of the centre of the board. Theres some good stuff on the smaller chips around the middle bottom as well. Just find the connections for the effects you like best and wire switches across them. You can probably fit more in if you use 3 way centre off switches.

If you want to avoid killing the thing stay away from the chips on the left of the board. I've known messing with these chips to wipe the memory, permanently bend the thing, or make the 505 unprogrammable. Not something you want to risk

[Jaicen]

Thanks man, that's just the sort of advice i've been looking for!
I haven't received my 505 yet, but that baby's gonna get bent almost as soon as I get it
It's a shame there are no realtime control possibilities, but I guess it's not too bad.
As long as I can get me a slice of sonic mayhem 
Thanks for your help, I'll be back here in a few days moaning that you made me break my 505... lol

[Jaicen]

Hey guys,
Just thought i'd drop by to let you know i've got my 505 and have proceeded to bend the hell out of it!
Nothing permanent yet, but i'll have pics and samples soon. Thanks for your help.

[Jaicen]

Ok guys, just another quick update.
I've got myself a ribbon cable and soldered it to the points listed below. The other end is attached to a printer socket (25pin DIP, not sure what they're called) which gives me  25 different outputs from the machine. It's already been modified (poorly) to provide seperate outs, but these were taken from IC and sounded terrible so I ripped them out. The printer socket is going in their place. Anyway, i've got 9 ROM pins and 9 pins from IC's 6-8, as well as resistor 82 leaving me 5 pins unconnected. The IC 6-8 group will have 9 two way (centre off) switches, allowing two simultaneous combinations, as will the Rom. I figured this was the way to go for simplicity's sake. Since i'm using a breakout box I can always make a patch-bay as well.
Does anybody have any suggestions for utilising these last 5 pins?? I was planning to connect some of the individual outs to them, so I need to know which of the caps is which instrument. Can anybody save me the bother of probing around??  I still need to finalise my switching scheme for the 6-8 group, that's gonna cause some headaches man!
Anyway, here's the pins i found to be the most creative:

IC8
5, 6, 9, & 13.
IC7
3, 5, & 6.
IC6
6 & 10.

ROM
3, 4, 7, 11, 13, 27, 24, 23, 15,

[voodoolikeudoo]

Individual outputs are taken from the vertical row of resistors above the sound ROM aren't they? Different sound from each resistor apart from a couple that are doubled up.

[Jaicen]

Yeah I know where the outputs are, I was just hoping that someone could tell me which resistor/cap is which sound, save me the trouble of making an audio probe.

Also, is the TR-626 significantly different in terms of bending to a 505?? Any thoughts?

[Circuitbenders]

626 is much along the same lines as the 505 but getting  it apart so you can get at the inside of the front panel is ridiculously tricky. Seems to be held together by at least 200 screws 

[Evoke.T.Macabre]

Ok, i've just got myself a TR-505 which i'm planning to bend.
I don't really care for the stock sounds, i'm looking for something a little grittier and gnarly, more industrial.
I've found this site: http://burnkit2600.machinenoise.com/505_mods.html
which has some good tips for what to bend etc, but since this is my first bend, i'd like some guidance.
I'd like to use switches for the bends rather than a patch bay, as I know i'd just lose my leads and I want it to look neat ( I just want it to sound messy )I want to have lots of realtime control using pots as well.
So, which of the bends will I get the most mileage from using switches and pots?? I know it's a case of me sitting an fiddling, since that's what this is all about, but some hints would be nice
I'd also like to know if there's a way to change the sample rate to pitch the individual instruments, since the 505 has no stock option for that, though it does already have the 5 outs installed (not by me).
Ok, one last question: What can I do that's guaranteed to destroy my 505! I really don't want to waste a nice old machine like this with stupdity
Thanks for your help guys,
*j

have you thought about using rotary switches for your IC reconnects??  in that sense you could scroll through a bunch of different patches just by turning the switch.  what you could do, would be to have the patchbay still and use dpdt's to go between your ptchbay and the rotary... then you could set up differnt patches that you liked and them all connect to the rotary in the various sections, flip between them with the rot. switch and then back to the patchbay with the dpdt's... just a thought.