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Author Topic: TR-505 Pitch & other things  (Read 12514 times)

mq4

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TR-505 Pitch & other things
« on: January 03, 2008, 02:52:46 PM »

Hello!

I just got a hold of a TR-505, which apparently is great to bend.
I do however have a few questions for you experienced (hardcore) benders  ;)
I was thinking of making a mixer, with slide pots controlling individual drums (like the one  squelchbox made), a pitch knob, perhaps a dist knob (if I manage to find a good spot, and figure out how to wire it) and a few switches for the different bends.

Now, two things:
1) Is there anything I should think about when experimenting with it or wiring it? Anyone got any general tips?
2) I found a picture of the pitch know wiring, but I don't understand it, could anyone explain this?
Pitch knob picture

Thank you!
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Circuitbenders

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Re: TR-505 Pitch & other things
« Reply #1 on: January 03, 2008, 03:32:36 PM »

That pitch knob is very weird. I tried it on a 505 and it will take the pitch quite a way up from normal but not down. The weird thing is that if you use a metal pot you get a kind of bizarre theremin effect where just putting your hand near the pot makes the pitch a little unstable. You also get a different pitch curve depending on if you are turning the pitch up or down and how fast you turn the pot. It does the job but its very strange.

You wire it in by just taking a wire from either side of that resistor to the middle and one of the outside connectors of the pot. The unused connector should be wired to the middle.

If you've been looking at the burnkit site, assuming you got that pitch wiring pic from there, you already know pretty much everything you need to know about bending a 505. If you are using sliders the main thing you are going to want to worry about is getting the component positioning right. Bear in mind that you will actually have to close the case so check out the positioning on the components on the board. There is a big capacitor on the right hand side just above the volume & tempo pots that i always remove and glue onto the board elsewhere as otherwise it just gets in the way.
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i am not paid to listen to this drivel, you are a terminal fool

mq4

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Re: TR-505 Pitch & other things
« Reply #2 on: January 03, 2008, 04:22:32 PM »

Thank you very much!
About the sliders, I might reconsider that, we'll see.
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computer at sea

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Re: TR-505 Pitch & other things
« Reply #3 on: January 03, 2008, 09:08:55 PM »

I'd think about adding a breakout box.  There's just so much stuff in there that you'll have to leave a bunch out if you use the regular casing. 
I did one of these a month or two ago.  The whole time I was very cautious not to touch the two big chips that you're supposed to stay away from.  After hours and hours I finally had all the bends I wanted and was ready to run wires.  Unfortunately, once I got everything wired to the board and started threading the wires through the hole I made to go to the breakout box something brushed up against the big chips.  Now my guy is perma-bent.  It's not really a big problem, because all my bends still work, but as a point of tidiness, I always try to preserve the stock functions of the devices I'm working on.
Anyway, my point is this:  Do be careful with the big chips. 
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mq4

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Re: TR-505 Pitch & other things
« Reply #4 on: January 03, 2008, 10:13:48 PM »

Thank you for the advice.
Quite honestly, I'm a little afraid of bending it, because I've just started my bending adventure, and don't want to fry anything. We'll see - I'll experiment and see what I can do.

Could you specify exactly which chips to stay away from?

By the way - the burnkit site said to "use a 2.2k in parallell to R82" in order to get distortion on the whole mix.
Now - does that mean to cut a leg off R82 and solder a 2.2k pot in between?
« Last Edit: January 03, 2008, 10:15:23 PM by mq4 »
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Signal:Noise

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Re: TR-505 Pitch & other things
« Reply #5 on: January 04, 2008, 08:04:24 PM »

Yeah definitely do a break out box, there's very little room inside the 505 for wiring. If I have the readies this yeah, I'm hoping to see about making a custom rackmount case for a modded 505.
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mq4

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Re: TR-505 Pitch & other things
« Reply #6 on: January 04, 2008, 08:52:29 PM »

Hmm, I've seen a lot of 505's with controllers in their own case. Those were just a few controllers, like 6 switches and a  few pots... And that's basically what I want. Maybe a patchbay. Nah, we'll see how many bends I'll find.
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mq4

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Re: TR-505 Pitch & other things
« Reply #7 on: January 08, 2008, 09:55:11 PM »

I found some great bends, and decided to make a patchbay in an external box. Now - if I use RCA jacks for the patchbay, how do I connect the cables? Say I use an IC that has 14 pins on each side (a total of 28 pins). If i connect two pins, the sound changes. But you connect two wires to an RCA jack, that would make the sound change as soon as I insert the cable. Can I wire just one wire to a jack, so that I get a change in the sound after connecting two different jacks?
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Re: TR-505 Pitch & other things
« Reply #8 on: January 10, 2008, 04:38:49 AM »

Quote
Can I wire just one wire to a jack, so that I get a change in the sound after connecting two different jacks?

Absolutely.  This is how it works. 

If you're installing a bigger patch bay it can be cool to leave one or two jacks that do have two wires connected to them.  That way you can get a known glitch just by inserting one end of an rca cord and have the possibility of combining those two points with another point and getting a totally different glitch.
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mq4

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Re: TR-505 Pitch & other things
« Reply #9 on: January 10, 2008, 07:32:11 PM »

Ah, okay. Sounds great, although I must admit I'm scared as hell to solder the thing... I'm afraid I'll do something wrong. So it'll wait some time, until my soldering skills get better.

Does it matter which lug you connect the wire to, on the RCA jack? It shouldn't, because it will still lead electricity when connected, no matter which lug it is, right?

About the patchbay, great idea! I'm planning something along the lines of a 40-jack patchbay - using all the pins on the "synth tone" IC, and some other bends. Also, a few switches for distortion and a pot for pitch.
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Many_boomers

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Re: TR-505 Pitch & other things
« Reply #10 on: January 18, 2008, 01:37:46 AM »

I just got one too. And after my attempt to bend my rx11 I'm a bit gunshy of destroying it, although I do want it bent all to hell none the less...
Poor bastard who I bought it for payed $129 canadian for it, and could figure out how to change patterns...

I have an Idea for a patchbay that also has a nice array of pots, all color coded with matching sets of jacks built in right next to it so I can vary current from bend to bend, or use straight point to point at my leisure. Is this feasable? I don't want to fuck this thing up if I don't have to. Most of the time they are expensive, but than again most dated piece of shit electronic instruments are thanks to us assholes...  ::)
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