Step 1: Let's See What's Inside...
Looking more at what needs to be done a bunch of components would have to be desoldered and wired up to the board to allow these to be accessible from the rack frame - these pieces being the four audio jacks (input, headphone output, and left / right outputs), the 2 rotary encoders (for amp model and effect selection), the 8 potentiometers (for various input), the power supply input, and the 2 MIDI jacks.
Since this will be inside the rack, I'd have to also create a break-out circuit for the display LEDs and for the buttons / switches... on to planning.
Step 2: Planning It All Out...
The resulting images are attached... they might be hard to see because of the detail of the lines and the small image sizes here, but trust me, the time and effort spent on this stage was well worth it. The final rack-mounted unit's dimensions and component placement went as planned.
Step 3: Time to Get De-soldering...
Anyhow - so, I busted out the old trusty Weller soldering iron, desoldering bulb, wick and suction-thingie and went to town... I removed all the jacks, potentiometers (which were all a pain in the butt), the rotary encoders (which were an even bigger pain in the butt to get out without breaking the leads), the 7-segment display, the LEDs, and the power jack. I didn't want to bother with the RJ-45 plug that they have to connect to a foot pedal, mainly because I knew I'd be controlling my unit via MIDI and my Behringer FCB-1010 footboard anyhow... why bother...
The image attached shows the desoldered board (three of the potentiometer wires have been attached too - I didn't stop to take any pictures while de-soldering, unfortunately)
Step 4: Creating a MIDI-thru
(BTW - this circuit works perfectly! I've not have any sync errors or speed delays patching through this MIDI-thru)
Step 5: Wiring Up the Jacks, Pots and Encoders...
To play it safe too, I flatted out the smaller capacitors on the board - and if you think that's a lot of wires now... wait a couple of steps...
Step 6: Preparing the Rack Case
The text for the labels was just printed out from a regular inkjet printer onto regular paper - I then smeared some clear-drying superglue across them to get them to stick to the painted metal. Not the most clean way (or professional way) of doing it, but it works, and none of the labels have come off to date.
The covering over where the LEDs and the 7-segment display is came from some old thin, black wire-mesh I had lying around.
For all the cuts / dimensions / spacing / etc. - this is really where the AutoCAD drawings came in handy -
Step 7: The LEDs and 7-Segment Display
From the AutoCAD drawings, I had cut out a piece of breadboard to mount all the components on and the first thing I did was to solder the wires onto the new indicators. Each of these wires would eventually be soldered onto the appropriate place on the original PCB where I removed the original component...
When the back-side of the indicator breadboard was complete, I soldered on (directly to the PCB) wires for the push-button switch connections - after soldering each connection, I tacked down the wire with some hot glue to make sure it didn't shift.... (one note though - in the end, my connections for the push-buttons failed somewhere, so none of the push-buttons work - which is OK, because I control everything via MIDI anyhow... but if you want your buttons to work, use caution here!)
And then finally - the connections from the indicator breadboard was soldered onto the PCB... now that's starting to look like a mess of wires... At this point, I mounted the PCB in the rack frame to make it easier to work on...
Step 8: Mounting It All in the Rack Unit
I then put the front faceplate on and attached the switches - and the the back with the jacks attached.
Then I compressed all the wires and put the top on...
Step 9: All Done! Fire It Up and Test It!
After some tests with a guitar plugged in, I deemed it worthy enough to put into the rack. All knobs and MIDI functions work great - and with new audio jacks on it, the sound is quite clear. As I mentioned before, it's disappointing that the push buttons don't work, but that's OK because the MIDI functionality works 100% fine.
Step 10: Finale and Parts List
Here's a list of parts used to get this done (purchased from both Mouser and Jameco)
103-1211-EV - Pushbutton Switch (x8)
540-SRB22A2FBBNN - Rocker Switch
589-7100-410 - ProtoBoard (10x4")
696-SSA-LXB10GW - 10 segment LED bargraph (green)
696-SSL-LX2573GD - 5mm x 2mm LED (green - x20)
604-SC56-21GWA - 7 segment LED (green x2)
565-7160 - 1/4" stereo jack (3 cond. x 5)
161-0005 - 5 pin DIN MIDI Jack (female x 3)
546-RMCV19018BK1 - Rackmount Enclosure - 1U x 8" deep
Toggle Switch (AIR): 75969CB
22 AWG Hookup Wire: (100', black): 36792 and/or (100' red): 36856 - solid
1/4 watt 220 ohm resistors (min. 100)- 690700
1x 74HC14 (hex inverter): 45364
Random hardware I had around...
PCB Standoffs (4x for PCB)
3/4" x 3/4" (1/16" thick) aluminum L bracket
Screws/Nuts for DIN Jacks (6x)
Screws/Nuts for Alum. LBracket/Plates