Finished! (SIDx1 build notes (with pictures))

[AndrewMartens]

Introduction

About two years ago now I had bought my SID and CORE boards, and at the time I had populated one of each, checked VDD and VSS, and then I had to put them away (moving, getting married, family fun, buying a house, moving, more family troubles, etc.).  But I finally started getting keen about the MIDIbox family of products again, so it seemed like a good time to "nerd it up", as I like to say.

Things I Did Wrong:

• I had wired up the LCD correctly, until I made a few hasty mistakes on my rough pinout sketch and reversed VDD and VSS.  Whoops!  This one was pretty obvious, since it browned-out my bench supply.  Once I took a look and realized that red went to ground and black went to VDD, it was just a quick fix.
  
  
• reversed the wires on my MIDI OUT.  Had a sketch, triple-checked it, and still did it backwards!
  
  
• somehow in fixing the first two problems, I managed to burn out one of the MIDI outputs on my MOTU MicroLite (now it appears to be a 5x4 interface).  NOT HAPPY.  Next time I'll throw in a crappy PCI soundcard to use.  I still have no idea how I did this, since I had disconnected the MIDI cables during troubleshooting.
  
  
• when creating the DINx1 on a veroboard, I managed to connect the +5V line in series with the capacitor instead of in parallel with it.  Easily traced, easily fixed.
  
  
• I had to rebuild a CS_A HEX file twice, as I hadn't properly cleared out all of the parameters from the original "full" 6581 ASM file the first time.  The symptom was that the buttons and encoder behaved very oddly, bringing up odd pages of parameters, jumping around, etc.  The encoder was backwards initially, which made it a bit jumpy for some reason.  I reversed the pins and it's smoother, though still jumps just a bit sometimes when I'm trying to go slowly.
  
  
• using an R2 SID board and an R3 core, I foolishly connected SC to SC on the connection.  After finding that I had a silent SID (and having fixed all the above issues, and I had checked all the voltages before connecting the SID), I double-checked the schematics.  Sure enough, there we go - just connect MD to SC, and it works!
  
  
• installing the power plug in the middle of the back of the case was rather silly, and I should have just put it off to one side.  Oh well, that's what I get for not bothering to redo the cabling that was two short to reach from any other position...
  
  
  
  Things I Did Right:
  
  
  • checking pins with a multimeter *before* plugging in ICs.  That made me reasonably sure that I hadn't blown anything up.
    
    
  • pluggable headers are very nice, and I did use some for the back panel hardware.  But I just didn't have any 4- and 5-pin ones available, so I went with the direct-wired route for those connections.  The latter is faster, but it gets somewhat cumbersome even with just four boards joined together.
    
    
  • getting a good soldering iron.  Fortunately (?) my Radio Shack soldering iron burnt out this weekend, so I got a nice Weller WTCPT soldering station.  It made all the detail work so much easier, especially connecting the ribbon cable to the SIL and DIL headers!
    
    
  • checking the forums and the website.  There's a lot of great information out there, and a few resources that I didn't have to quite resort to (ie the SID interconnection test).  Every time I got a bit perplexed, an hour or so looking at the website and the forums usually did the trick and helped me find what I needed.
    
    
  • while reversing the encoder, I also removed the oscillator from the SID_V2 board and wired up the PWM connection.  After all, that's what my original design from five or six years ago (when I started designing my SIDGroove synthesizer) had called for.  No more gate glitches.
    

  Things Still TBD:

• connect analog joystick to control filter cutoff / PWM / whatever
  
  
• check the filter capacitors that I used in the SID.  I'm honestly not 100% what it sounds like with good caps and what it sounds like with less-good caps.  I put them in there two years ago, and I'm not sure if I used mylar or styrene at all.  Could be something else.
  
  
• create front panel (rough in with cardboard, then drill/cut panel)
  
  
• paint panel, attach interface components
  
  
• make some music!
  
  
  
  And now, PICTURES!
  
  
  
  DINx1 + Bankstick (awaiting ICs, top):
  
  
  
  
  
  
  DINx1 + Bankstick (bottom - next time use macro mode on the camera):
  
  
  
  
  
  
  A working Core module... I felt pretty good once this was working:
  
  
  
  
  
  
  The case is drilled, and the standoffs are ready to use.  They turned out to be just the right height:
  
  
  
  
  
  
  All wired up, and no place to go (next time, make the audio cable shorter; at least it's shielded):
  
  
  
  
  
  
  And a nice in-situ glamour shot of everybody's favourite:
  
  
  
  
  More pics to come once I've got the front panel all wired up!

[SLP]

nice!  :)

I think I'll use PCB-mounted switches and encoders instead of panel-mounted ones when I'm building my SID.

I've built a MB+ some times ago and it was quite hard to put all the cables in a housing which was even bigger than your one  :P .

matthias

[AndrewMartens]

I think I'll use PCB-mounted switches and encoders instead of panel-mounted ones when I'm building my SID.

I highly recommend it.  Just make sure you think about your mounting points for the PCBs when you do it.  In the half-cased picture, you can just make out the drill hole at either end of the 4-button PCB; hopefully that will be enough.  I was originally going to put the EXEC button on that same PCB, but I found there was a lot of torque applied to the encoder (which was just going to be panel mounted), and I didn't want it coming loose all the time.  Put those two on their own PCB, since they're on the same side of the DIN module, and the four mounting holes PLUS the encoder nut should be more than adequate.

This was originally going to be a dual-SID, but then I realized (a) the case was too small, and (b) I only had one more button, and the series had been discontinued.  Fortunately the awesome VST-control exists, so I'll just build a headless SID as my second unit.

[SLP]

• create front panel (rough in with cardboard, then drill/cut panel)
  
  
• paint panel, attach interface components

As you're giong to make your front panel yourself:

How do you know where to make the holes for the PCB-mounted buttons?

...and do you know a company which sells cheap (!) enclosures

for a SID with CS??  (free samples ;D)

matthias

[AndrewMartens]

As you're giong to make your front panel yourself:

How do you know where to make the holes for the PCB-mounted buttons?

There's at least two ways to do it:

(1) measure everything with a digital caliper and plot it on the computer, then print out a copy to ensure your plan lines up with your hardware.  Or you can do the less professional method, like I'm going to do, which is:

(2) cut out a cardboard dummy panel from a cereal box, line up your interface components (buttons on the PCBs, LCD, joystick, LEDs, etc.), and use a fine marker/pencil to trace around the outside.  Cut out the openings with an exacto knife.  Match up the components, and hope you did it right.  If not, repeat - it's just cardboard at this point.  Once everything is in place, mark the screwholes for your PCBs.  Cut those out (or drill through into a piece of wood, whatever), and then mount everything to the cardboard with screws.  Yes, somewhat time-consuming, but if you've just got the one panel, you don't want to screw it up.  If you're happy with it, then remove all the components, and mark all the cuts/holes on your nice panel.  Grab your drill / dremel / whatever and go to town!

At least, that's my plan.  Hopefully it will work...

...and do you know a company which sells cheap (!) enclosures

for a SID with CS??  (free samples ;D)

I just bought a Hammond enclosure from Digikey that seemed to fit my needs.  There's a number of threads on the forums about good enclosure choices, but I'm not aware of any that offer free samples.

[AndrewMartens]

Another evening, another update.  Today's progress:

The Joystick

Thanks to this thread - http://www.midibox.org/forum/index.php?topic=5708.0 - and also this one - http://69.56.171.55/~midibox/forum/index.php?topic=3375.0 - I have my filter hooked up and it seems to be working fine.  It sounds like the cutoff is around 120~121, and the resonance seems to be working well enough, despite its limited resolution.  Currently it's wired with a 100nF cap between +5V and GND on each of the 10k potentiometers, and it controls without any jitter at all (that I can hear).

I'm still not sure about my filter caps, as the "full resonance" sound is rather gritty and distorted.  I like it, but I'm just not sure if the caps are correct.  Guess I'll have to go back and listen to a bunch of other SID samples to figure it out.  I managed to dig up the Digikey label for the caps that I have - turns out they're polyester film, whereas I thought I had aimed for polystyrene originally.  That'll be an ongoing investigation, but they'll be easy enough to swap - and I have a set of ceramic caps also available if need be.

The Case

Coming along so far, I did a mock-up with cardboard, transferred it to the aluminum plate and started drilling.  Of course there's always going to be some error, and the drill holes ended up being spaced out a bit too far due to drill slippage.  I'm up to my largest bit size already and I need to enlarge the pushbuttons just a bit, and the joystick isn't even close.  I'm leaving the LCD until last, because even with a dremel-clone it's likely to annoy me.  Assuming I can get it finished tomorrow, I'll slap a coat or two of primer on it.  Then perhaps I'll paint it a nice soft blue like our kitchen (using left over house paint, of course!) or possibly a soft off-white, add some hand-lettering, and then a clearcoat over top.

[TK.]

I really would like to see such build notes (what can be made wrong, what can be made right, how to build a simple DINX1 module) in the Wiki! :)

Best Regards, Thorsten.

[Mr modnaR]

i have a low profile alternative (built on trackboard) to your mod matrix too TK, where would be the best place in the Wiki for it?

cheers

[AndrewMartens]

I really would like to see such build notes (what can be made wrong, what can be made right, how to build a simple DINX1 module) in the Wiki! :)

Best Regards, Thorsten.

Hey TK!

That's my plan - once I finish putting it all together, I'm going to transfer a number of these notes to the Wiki.  There's just one more mod that I need to finish up (probably tonight) before I complete my panel and mount everything.  It's just a simple filter button and four LEDs (for OSC1-3 and the external input) to enable the filters without going through the menus.  It's a standard part of CS_C, I know, but I just figured I'd hack it into my last remaining input on my DINX1 module, and document the process.

Slap that up on the Wiki, and then people can hopefully figure out how to map a few buttons themselves.  Not that it's particularly difficult - everything is already either on the forums, the schematics, or documented in the code.  You've done a fantastic job making it easy to use and modify, Thorsten, and you should be commended on this more often.  MIOS and the SID application are excellent!  ;D

[AndrewMartens]

Well, it's been a month, but I finally have had time to get back to the SID again.  After reading up on various types of capacitors, I tried swapping in some 470 pF ceramic caps (good 5% COG/NP0 ones) for the polyester film caps that I had put in there.  The sound was a bit smoother, but the filtering was very heavy, and at the higher levels of cutoff only just started to open up a bit.  Adding any resonance just brought in a load of distortion.

Based on this thread - http://www.midibox.org/forum/index.php?topic=3589.0 - it sounds like I need some smaller caps.  I'll have to wait until my order arrives from Futurlec, because it has some variety packs of ceramic and mylar caps in it.

On the plus side, I managed to get my front panel painted, labelled, and mounted all of the parts tonight.  Fixed the improper drilling of the joystick screws, had to fix a few other drill spacing issues with some washers - the PCB holding the four buttons under the display is actually mounted on a slight angle so that the rightmost button doesn't bind on the edge of its hole.  I also managed to fix my "cut the LCD hole way too large for some unknown reason" issue by drawing on a piece of clear plastic with a sharpie, and mounting it in front of the LCD.  Pictures will have to wait for a day or two until I get a chance to buy some white model paint and go over all the shiny screw heads that are messing up the look of the panel.

Then I'll tweak the customizations a bit more, and then post them to the wiki... same goes with some before/after samples of that darned filter.  Getting close now!  :D

[HL-SDK]

Excellent writing, I've made mistakes too, I'm glad your box is working!

Also, panel mount is almost always < PCB mount... But PCB mount is more expensive

PCB mount lets the copper do your wiring for you! all you have to do is solder in, drill to case, done!

(I wish I had an etching setup so I could do this :'()

[AndrewMartens]

Excellent writing, I've made mistakes too, I'm glad your box is working!

Also, panel mount is almost always < PCB mount... But PCB mount is more expensive

PCB mount lets the copper do your wiring for you! all you have to do is solder in, drill to case, done!

(I wish I had an etching setup so I could do this :'()

Heh... mine is technically "PCB mount", except that it's a series of small PCBs that are then each mounted to the front.  Including the LCD and joystick, I had 18 screws holding everything in place - not too bad, except for some drilling issues on the buttons.  Ideally I would do a custom DIN + encoders + buttons all on one PCB, but that's going to have to wait for my "Green Bastard" synth coming late next year.

[AndrewMartens]

Well, it's finally finished!  I'm just finishing up my documentation for the Wiki, but in the meantime I'll post up some final construction pictures.

I'm not the type to spend a lot on an enclosure or a panel, so I grabbed a sharpie and went to town labelling it by hand.  The white coating on the metal is just plain old Tremclad spraypaint, which worked quite well.  As I mentioned above, I cut the hole for the LCD way too wide (wide enough to fit the LCD through, actually) - so rather than having to order a bezel that may or may not be the right size, I used that trusty sharpie again on a piece of hard clear plastic, and drew in a crude window.  Everything else on there should be pretty straightforward.  The knob on the joystick is actually borrowed from my Red Sound Dark Star - I haven't opened the case on that one, but it looks to be exactly the same joystick.

Here's a few more "making of" pictures:

Drilling/cutting template

Joystick wiring

Putting it all together

Quality workmanship?  No, not really.

Front panel view

Left angle product shot

Right glamour shot

The ports around back

The MIDIbox SID makes some friends

[Mr modnaR]

i like it! it kinda reminds me of 80's russian nuclear power station control panels! (meant in a good way!) let's hope your box doesn't go into meltdown!  ;D **audience groans**

(ps, i could have also said something along the lines of: 'i hope you're not fission for compliments?' but i decided that's too far... ::))