TR-626 first big bending project

Sk5man · June 03, 2009, 11:50:48 AM

Hello,

Since 1,5 week I'm working on my first 'big' bending project, a TR-626. The TR is in good condition, and that's why I've decided to make an external controller for it. The connection to the controller will be via DIN 25.

I will upload some pictures later today, and if there are some good suggestions for a pitch knob or other usefull bends just let me know.

Regards,

LoFi-Ninja · June 03, 2009, 04:05:21 PM

Burnkit2600 has the ultimate guide to TR-626... Use google next time..

Sk5man · June 03, 2009, 05:57:07 PM

I've already gathered the most usefull information from that site, and the connections to the 8735KY chip have already been made. All I wanted to try now is to create a turnable Pitch knob, and i haven't found any details on how to create it. I havn't got any clue as well for which kind of pot needs to be used.

If someone has details for this it's much appreciated.

Regards,

Gordonjcp · June 03, 2009, 07:45:46 PM

There isn't really a way to just tack on a pot for controlling pitch. You could use the infamous LTC circuit to generate a clock.

Bear in mind that the two voice ASICs in the TR626 are fragile as hell. That's why mine doesn't work any more...

Gleix · June 03, 2009, 09:10:38 PM

I just posted this topic almost exactly a few weeks back...

Shoulda checked there.

My 626 is project is coming along though - my panel from frontpanelexpress should be in monday:

I was going to make an external controller but with everything I wanted to do to it I'd need two 37 pin connectors, and there's no easy way to rig that up... and 37pin connector cables are expensive. So this case was built. I also wasted two nice pieces of metal before realizing there's no way in hell I can evenly drill a grid of 96 patch points by myself.

I'm making a large .doc file explaining every mod I'm doing to the 626. I'd be happy to share.

Circuitbenders · June 03, 2009, 09:25:03 PM

Quote from: breakbeatnazi on June 03, 2009, 09:10:38 PM
I also wasted two nice pieces of metal before realizing there's no way in hell I can evenly drill a grid of 96 patch points by myself.

I've been there

My advice for drilling big patchbays accurately is to get a column drill and clamp some kind of guide rail to it so you can drill holes in a perfect row.

Either that or spend the money on a nice frontpanelexpress one. If you live in europe Schaeffer AG is a better bet.

Sk5man · June 03, 2009, 11:01:59 PM

Hi, thanks for the tips, i have got one DIN 25 çonnector already full with the 25 points for a patchbay, and i'm planning on a second DIN 25 which I won't use at it's full capacity... Maybe in the future. I saw the thread about your 626 breakbeatnazi, and i have to say that's a stunning design. When it's finished i'd love to hear what it's capable of.

I'm getting some help for my design, my brother is working as a metal worker and he has acces to laser cutters and hydrojets. They will help me get a nice grid for the patchbay and backpanel. Since this is the first big project i will be happy to see it work rather than having a beautiful object which fails all the time...

I will try to upload some photo's later on...

gmeredith · June 04, 2009, 01:23:17 AM

I've found that the best way to drill accurate holes yourself is to make up a drill giude out of a small strip of thick metal. Drill 3 or 4 holes in it in a line exactly the right distances as the holes in the patchbay need to be. When you've done this accurately enough, now just clamp it to the patchbay panel and start drilling. If you've marked out lines and dots on the panel you just go clamp, drill drill drill, clamp, drill drill drill etc. until its finished.

Cheers, Graham

LoFi-Ninja · June 04, 2009, 08:10:37 AM

Also a drill press / bench drill, whatever you want to call it, is pretty much mandatory if you want good results. Not saying you can't do fine with a hand drill, but there's so many more things that can go wrong...

Sk5man · June 04, 2009, 01:45:14 PM

We, i hope that it will work according to my plan. I'm now going to create a small plate with two DIN25 sockets that fits in the backpanel where the cardridge holder was place originally. This, and the main interface plate will be made with the help of my brother. So I hope for a nice and accurate grid layout for a patchbay.

Thanks for al your advice untill now..

Gordonjcp · June 04, 2009, 02:48:57 PM

Y'know if you brought out *all* the pins on the sample ROM to a connector, and made a small mod to the PCB (add a pullup resistor and an inverter to the chip enable line) you could use it as a cartridge port for optional replacement 626 ROMs...

As for drilling accurate grids of holes, get a piece of veroboard and use that as a guide. Then you'll get accurate 0.1" multiples for spacing. You could also paste a piece of graph paper on top and mark with that. If you drill a spot on the surface with a PCB drill that fits through the veroboard without cutting into it, that will guide a larger drill when you come to bore out the hole.

You *do* really need a pillar drill though.