What to put on a mbSID v2 CS

Design Concepts
1

Short answer: I have the same number of sammichSID base PCB and control surface PCBs. Selling one separately to the other means I’m left with a potentially unsellable board. Not worth my trouble.

Long answer: Considering the MB-6582 base PCB already has the DIN/DOUT for a full CS, and the sammichSID CS also has DIN/DOUT for a minimal CS, combining the two is not only very redundant, it’s a bit of a wasted opportunity. It is so easy to stick a few switches on a prototyping board and connect them to the MB-6582 base PCB, and this not only is cheaper, you can make it exactly the way you want, instead of being forced to use the incredibly minimal sammichSID CS. I mean, if you want the buttons in the exact same places then you could do that now with prototyping board, you won’t need a sammichSID PCB… but if you add just a little bit more effort, you could use a 2x40 LCD or a 4x20 LCD and make something so much better.

Wilba,

I don’t necessarily need to use the sammichSID CS board. I was indeed thinking of using a 2x40 LCD, as I already have one. And some encoders.

I guess I’m more interested in the details of the DIN/DOUT configuration for the sammichSID…how you implemented the used definable buttons, for example.

Another option is to buy the MB-6582 CS board and only partially populate it. Sandwich the 2 boards like the sammichSID, then just run control wires for those switches and encoders that I want to use. I can see it being worth the $20 for improved reliability.

I would probably also want the feedback pots on the front panel. I would put everything in an old C-64 case and integrate the power supply.

A more general question of interest is : When using the full control surface, which controls get used the most? What is the optimum control surface complexity that lies between the sammichSID and the full blown CS-6582?

I’m also interested in being able to use the MB-6582 as more of a standalone device…kind of a Midibox SID jam box.

Don’t get me wrong – I’m very impressed by what you have done, but personally want something with a simpler interface.

Thanks,

Tom

2

There is nothing special about the wiring… “user defined” buttons are wired the same as any other.

Everything is configured in the firmware, so you can connect buttons and encoders to whichever DIN module pins you like (except encoders must be on DIN pin pairs like D0+D1, D2+D3, etc).

So basically design the arrangement you like, the MB-6582 base PCB has five DIN modules and you won’t need a switch matrix so this means up to 40 switches, one encoder needs two pins so let’s say you use 6 encoders, that’s 12 pins, leaving you with 28 switches. Similarly, there are three DOUT modules so you can easily drive 24 LEDs without a LED matrix, or up to 128 with a LED matrix. If you use more than 16, and need to use the 3rd DOUT module (the one with transistors under it), then you’ll need to change the resistor/transistor with just a resistor and bridge the transistor pads. Very easy to do, just letting you know not to stuff the resistors/transistors there until you design the CS.

Optimal CS between minimal and full? Hard to say… but I would think a 2x40 LCD with 10 select switches underneath would be good. Definitely would need SID 1,2,3,4 buttons/LEDs to control the four SID engines on the MB-6582 (another reason why sammichSID CS is not suitable - no SID 1,2,3,4 buttons!). Add Shift, Menu, Up/Down buttons. Add a SID L/R button + two LEDs (or dedicated SID L + SID R buttons!). A Play button would be ideal if you want to start the bassline sequencer without external MIDI input.

That would still leave quite a few spare DIN inputs for “user defined” buttons should you want them. Buttons to jump to commonly used pages (like Osc, Env, LFO, Filter) could be good.

For encoders, I suggest the menu encoder and five encoders underneath the LCD for the “knobs” parameter layer that would let you control the “custom” parameters per patch. Ideal for bassline mode. Each patch can have its own set of “knobs”, each knob can tweak one or more parameters depending on how you configure the patch. So if you are going to add a few encoders to a mimimal CS, then making them control the “knobs” layer is more useful than any other. If you have room, you could add two more encoders just for filter cutoff and resonance.

If 2x40 LCD is too big for your needs, consider using a 4x20 LCD (TK has added some nice bling to the top/bottom rows on this display, so it looks cooler than a 2x20 LCD for only slightly more space).

3

Optimal CS between minimal and full? Hard to say… but I would think a 2x40 LCD with 10 select switches underneath would be good. Definitely would need SID 1,2,3,4 buttons/LEDs to control the four SID engines on the MB-6582 (another reason why sammichSID CS is not suitable - no SID 1,2,3,4 buttons!). Add Shift, Menu, Up/Down buttons. Add a SID L/R button + two LEDs (or dedicated SID L + SID R buttons!). A Play button would be ideal if you want to start the bassline sequencer without external MIDI input.

That would still leave quite a few spare DIN inputs for “user defined” buttons should you want them. Buttons to jump to commonly used pages (like Osc, Env, LFO, Filter) could be good.

For encoders, I suggest the menu encoder and five encoders underneath the LCD for the “knobs” parameter layer that would let you control the “custom” parameters per patch. Ideal for bassline mode. Each patch can have its own set of “knobs”, each knob can tweak one or more parameters depending on how you configure the patch. So if you are going to add a few encoders to a mimimal CS, then making them control the “knobs” layer is more useful than any other. If you have room, you could add two more encoders just for filter cutoff and resonance.

If 2x40 LCD is too big for your needs, consider using a 4x20 LCD (TK has added some nice bling to the top/bottom rows on this display, so it looks cooler than a 2x20 LCD for only slightly more space).

So, if I used a 40x2 LCD (which I have), 5 of the buttons would have encoders underneath them, and the other 5 would just have buttons?

I like the idea of dedicated buttons to select commonly used modes, and encoders specifically for certain parameters.

In any case, I just ordered the MB-6582 PC board and additional parts. Planning the build in a C-64 case which should leave me plenty of control surface space along with the LCD. Already have a dedicated power supply that I “harvested” from a nicely built piece of obsolete equipment.

Thanks again. I’ll likely have more questions as the build proceeds.

Cheers,

Tom

4

So, if I used a 40x2 LCD (which I have), 5 of the buttons would have encoders underneath them, and the other 5 would just have buttons?

I think the idea was to have an extended “Step B” CS - 40x2 LCD + 10 LCD buttons + menu encoder and menu buttons. The 5 extra encoders (for direct access to the “knobs” values) do not necessarily have to be in any way assigned or connected to the menu buttons.

I like the idea of dedicated buttons to select commonly used modes, and encoders specifically for certain parameters.

You might wanna look for “elSID”, “mxSID” and seppoman’s “der brat” for some inspiration as they include some different concepts.