Ah the TR-505, on it’s own I’d considerit the red headed step child of Rolands highly sought after TR series of drum machines. Once Circuit bent however these things can be real beasts. I’ve bent one already. It was one my first mods that turned out to be an awesome sample source. After using the thing for a while, I’ve had a few ideas on how to make a better interface for live use.

Obligatory before image:

Recently, I picked up another 505 on ebay to use for bending. I received it not to long ago and was completely suprised to see the condition it’s in. Other than two of the drum pads not working the thing is in imaculate condition. It’s almost a shame that I’m gonna comletely rehouse thing thing and toss the case.

The Plan:
This time around I have some very ambitious ideas for my new 505. As I previously stated, I’m going to rehouse the thing. This time around though I’m going all out. I’m not completely happy with the way my last one turned out, it’s too fragile. This time around I’m gonna get the front panel made by FPE. (Front Panel Express) I had the front panel for my Midibox SID created by them and am still really impressed with how that came out. So for the front panel, I’m basically going to measure out the current front panel of the 505 and replicate that for the new enclosure with the additional holes for all the new controls that will be added. In addition, I’m going to add a patch bay again, but this time with a twist. Several of the points on the patch bay are going to be routed to a Highly Liquid MSA so that the bends can be accessed via midi and will be extremely flexible.

4/6/2010
I’ve made a few changes. Instead of the highly liquid MSA, I’ve ordered a Midify board from devision 6 to try out. With this solution I’ve got to get 12 potorelays. I’ve got a parts list going at mouser as I think of things I will need for this. I plan to place that order in about 2 weeks.

I’ve also just about completed the FPE file with the front panel layout. I’m waiting for the banana jacks for the patchbay to arrive so I can make some minor adjustments. Once I complete the fpe file, I’ll post it here. You can see the general layout below.

*UPDATE 4/20/2010 (hehe 420)

My mouser order just arrived. I put the 505 next to the new case, so that it’s easy to see the size of the new case. The new case is about 18 inches wide. I needed plenty of room for the patch bay and other controls.

As you can see the shafts of all the pots are different lengths. I couldn’t find ones that matched, so I’m gonna have to modify them so that the knobs all sit at the proper height once they are mounted inside the new case.

I had to chop a few milimeters off the top of the shafts on the faders, as well as one of the pots. Here’s a close up of what I did to the faders.

…and a group shot of all the faders and pots together, post modification.

now that I’ve recieved nearly all the parts I’m going to need, I’m rethinking the approach I should take to get all the parts mounted and soldered in place. It may be far easier to have a PCB made rather than use protoboard. The advantages are pretty obvious although it will bring up the total cost of the project. I’m not too concerened about that however, because if I ever sold the machine it would surely fetch a decant price on ebay considering the effort put into this mod. This 505 is gonna look like it rolled off the line at Roland bent to hell.

Update 5/24/2010

I’ve got another pic to share. I just got the face in the mail yesterday. Sadly, I measured the slots for the faders incorrectly and had to find some narrower replacements. I’ll be mounting the switch PCB and LCD PCB today using machine screws and some JB weld from Home Depot. I’ll post more pics of my progress on that later.

I started JB-Welding the screws for the LCD PCB over my lunch today. Here’s a couple pics of the method I used to keep the screws lined up with the mounting holes. Basically, I applied the JB-Weld to the screws while they were all mounted to the pcb, then attached all of them at once.

The fact that I’m rehousing this beast causes a few problems. One of them being that the button contacts stayed in place in the old case using little plastic nubs that get inserted through little holes in the rubber mat, and little holes on the PCB. Here are a couple pics to show my solution. It’s not the most elegant solution, but it works. What I did was take a long piece of completely stripped wire and weaved it through the holes. I used heat shrink tubing to ensure there are no shorts caused by the wire (fat chance that would happen, really) and to keep the wire in place.

Update 5/26/2010:

I finished mounting the button board last night and all the JB-Weld is now dry. So here’s where I’m at so far.

Update 5/28/2010:
Last night I made a run to the rat shack. and picked up a few things I needed; some toggle switches (they didn’t have momentary on type, so I may replace them in the future), and a battery pack for 8 AAs. However, in the processes I forgot to pick up a prtotype board for the midi switch array. So later tonight, I’ll be making another trip.

I did get the hookup wire connected to all of the drum swap/fill switches and all the bend points on the patch bay last night. Pics to come later. This weekend, I’ve got one of the more difficult parts of the build in front of me; assembling the midi switch array. I say “difficult” but I use that as a relative term. No part of this build is particularly difficult, but rather is time consuming and very involved.

UPDATE 5/30/2010:

I’ve finished the MIDI switch matrix, although it is still untested it is recieving MIDI. Below, you can see what I’ve done with the midify board. Basically, I connected each lead from midify to a solid state relay. I did this for simplicity. This circuit has since been replaced by 2 Highly Liquid MSA-P kits.

Here, you can see how I’ve turned an 8 x AA battery pack into a 6 x AA battery pack.

…and the switch and patch panel fun

My next few steps may take a while. I’ve got to test bends and take plenty of notes. I’m going to start looking for the bends I want to route to the patch bay. For these bends, I’m going to stick mostly to ICs 6, 7, and 8.