Advice/feedback at a crossroad: Modular or MB-6582

[fallenturtle]

I've finished building a basic single 6581, Core8, with display, midi i/o, and audio out and now I want to go bigger. At this point I'm thing I'm going to go with a stereo pair of 6581s and a stereo pair of 8580s but I can't decide if I should continue with my modular approach and get another core8 board and 3 more SID boards or if I should instead ditch what I've done so far and go with a MB6585 board. Here are some factors at play:

• I want to build this inside a 64C case (I already have one)
• I like the idea of the extra control surfaces that are part of the MB6582 but since the pre-designed control surface board is designed for a PacTec case it won't work with my 64C case, so I'll need to figure something out on my own, but based on the pictures here http://ucapps.de/index.html?page=midibox_sid.html I assume its possible (though I realize that's C64 case and not the 64C case.)
• I don't care that much about the matrix, so I'm considering leaving that off with the hopes that i might be able to design a control surface small enough that mounts on the under side of the top of the case and pokes up through the keyboard and Fkey holes.
• I'm not a electronics engineer, the MB-6582 looks little overwhelming, but I figured I got as far as building the above mentioned basic set so hopefully I can handle it and learn as I go along.
• If possible I'd like to stick with my 2 line display
• If possible I'd like to continue using 15V power adapter instead of using a C64 power supply.

Thoughts and opinions appreciated.

Thanks.

Edited August 8, 2017 by fallenturtle

[yogi]

Congrats on your SID synth!

The MB6582 is basically 4 cores and 8 SID boards copied to a single PCB. The cores are networked and the code for the cores is slightly different then the stock app. If you can poke around in the code, could change the FP options to your own needs and build the FP as you please. Don't know if you have any programming experience but it's not too hard and there is plenty of info on the wiki.

There is a new MB board supplier They are carrying the main board for $24.99, http://modularaddict.com/manufacturer/midibox  

So using the main board saves you alot over modules. Without the interconnecting.

There are a few threads here on the PSU and the MB6582 is flexible for setting up the power supplies.

Good luck,

Yogi

 

[Smithy]

Theres a log here of a build which uses the MB-6582 base board and a C64 (not c64c).

http://www.subatomicglue.com/sidl0g/#07.21.2007

 

it should give you some insight as to whats involved.

Edited August 8, 2017 by Smithy

[Hawkeye]

Imho: go mb6582 for the baseboard, it saves a lot of wiring madness and is just a clean solution (and it just became available again in Modularaddicts shop :-)).

You can always build a custom CS from there, but might need to modify the code a little, but it should be possible to do so. You can also use the baseboard without CS and test it with software panels like the ctrlr panel, TK. made some time ago...

Many greets,
Peter

[fallenturtle]

Thank you for the advice. I'm going to go with the MB-6582 and hopefully since the 64c case is a little longer than the breadbins I won't have to cut the board.

Regarding the code, does the software see the MB-6582 board and make assumptions on the CS or does it just view the board has a collection of modules?

I wonder if Modularaddict will start selling programmed PIC chips like SmashTV did or if I'll need to buy/build a programmer.

[Hawkeye]

Regaring the code question:

If you don't want to use standardized MB6582 CS switch/encoder/LED routing (which is expected by the supplied mb6582 hex on ucapps.de), you have to configure and build your own hex (there are include files that allow that modification). To do that, you have to get the MIOS8 toolchain up and running, it may take a bit of time before compilation works, but it is doable.

E.g. check:

http://svnmios.midibox.org/filedetails.php?repname=svn.mios&path=%2Ftrunk%2Fapps%2Fsynthesizers%2Fmidibox_sid_v2%2Fsetup_mb6582.asm

An alternative to modifiying that code is to map everything just like the MB6582 frontpanel did (you can omit the LED matrix for example), then you could run the standard firmware. Be aware, that everything is based on input/output matrices for the MB6582, so wiring might need to be rather complete to work. There should be a schem of the MB6582 CS floating around here somewhere!

Have fun!

Best regards,
Peter

[fallenturtle]

Just now, Hawkeye said:

Regaring the code question:

If you don't want to use standardized MB6582 CS switch/encoder/LED routing (which is expected by the supplied mb6582 hex on ucapps.de), you have to configure and build your own hex (there are include files that allow that modification). To do that, you have to get the MIOS8 toolchain up and running, it may take a bit of time before compilation works, but it is doable.

E.g. check:

http://svnmios.midibox.org/filedetails.php?repname=svn.mios&path=%2Ftrunk%2Fapps%2Fsynthesizers%2Fmidibox_sid_v2%2Fsetup_mb6582.asm

An alternative to modifiying that code is to map everything just like the MB6582 frontpanel did (you can omit the LED matrix for example), then you could run the standard firmware. Be aware, that everything is based on input/output matrices for the MB6582, so wiring might need to be rather complete to work. There should be a schem of the MB6582 CS floating around here somewhere!

Have fun!

Best regards,
Peter

Oi, maybe I should stick to modular after all. Most of my coding capabilities are limited to web tech.

[Hawkeye]

Just now, fallenturtle said:

Oi, maybe I should stick to modular after all. Most of my coding capabilities are limited to web tech.

Ahhh, there is not thaaaat much diifference between javascript and PIC assembler ;-)

You could still go for option 2: wire your CS like the MB6582 control surface... there is no voodoo involved, the MB6582 CS consists just of a lot of interconnections, diodes, leds, switches and encoders - it can be rebuilt on veroboard sections, that fit better in a C64C case!
On the other hand, if you are strapped for time, the recommendation is to wait for the CS PCB to be available again and to build a standard MB6582 in a Pactec case :-).
Going fully modular in a C64C case is of course still another option, but there will be a lot of spaghetti in the case! :-)

Many greets!
Peter

[fallenturtle]

Quote

http://svnmios.midibox.org/filedetails.php?repname=svn.mios&path=%2Ftrunk%2Fapps%2Fsynthesizers%2Fmidibox_sid_v2%2Fsetup_mb6582.asm

I don't suppose its as easy as just changing some values in that file and recompiling, is it?

I think I might need to reconsider what I want in a control surface... if I aim too high I might not ever complete this. As much as I'd like to have some built in knobs to tweak stuff, the truth is that I won't be using a device in live stand-alone playing position, I plan to use it with my DAW and thus a lot of things can be controlled via my PC (and I also have an external midi controller with its own knobs I could map).

If I decided just to use the Minimum Control Surface with the MB6582, would I still need to edit the code?

Edited August 9, 2017 by fallenturtle

[yogi]

Hi,

Yes, that setup file sets the options for mapping CS controls to firmware routines, within limits. So rearranging LEDs, buttons and encoders connections is a matter of changing this file and compiling. To add new features would require adding to the main source. If you look at this file closely, you'll see a section for the build options of MB6582 or sammichSID; these flags are for the re-arranged CS of these projects. They use SR IO matrices for all control elements. As opposed to the 1 to 1, SR I or O pin to a CS Element as you do with the standard build.

Like all the synth projects, most everything can be controlled over midi with CC and SysEx messages without changing the code. The most min system would be a Core and a SID board, this is playable via midi. With a min CS (step B), synth prams can be changed through the menu layers. The Full (step C) CS allows less button pushing, having a dedicated controls or displays for most of the synth sections. The MB6852 or sammichSID just improve on the full CS by minimizing shift regs. Even though there is code for a specific control or LED the synth will work if it's not attached.

From the MB6582 Wiki

Quote

You don't have to use the DIN/DOUT at the bottom of the PCB, and you don't have to use the optimized switch/LED matrix I designed to get a “step C” control surface with only 8 shift registers, and you don't have to use a “step C” control surface (or any control surface). However, TK has kindly done all the code changes to support the optimized switch/LED matrix so you can have a big control surface with only the shift registers on this PCB.

. So you could use the base board, without the bottom SRs, and a min CS connected to the first core's J8/9 and I think just the stock FW on the cores ( each with a different ID). If anyone can confirm?

Yogi

 

Edited August 9, 2017 by yogi

[jjonas]

fallenturtle, I started my MIDIbox career by making a stereo SID modular and then I made it bigger with complete control surface. My opinion on a large modular is that potentially it's a maintenance nightmare unless it's done right. I suppose you want to build it and then concentrate on making music with it rather than on maintaining it. Of course with most DIY some maintenance will be required at some point or another, but I'm sure every DIY'er knows what I mean.

A large modular can be done in various ways, and for example if you make DIN/DOUT connectios to encoders, buttons and LEDs with headers and crimp connectors (Dupont, JST etc.), that's closer to "doing it right" rather than soldering wires straight to buttons etc.; these are connections that might break if the wires move around over time when the synth is sometimes moved etc., or when you have to open the case and fix something else you are likely move the wires, and cause another problem when a soldered connection breaks somewhere. (The latter solution is what I did with my "big modular", and in my opinion that was a mistake.)

My solution was to give up the modular and build an MB6582 in a PacTec case. I think that was the right solution (for me at least). Certainly it's more boring than a DIY case and the DIY control surface that goes with it, but in my opinion it's less trouble. And of course the MB6582 CS board is not available at the moment, even though Modular Addict does say that it will be "available soon".

You choose to do what you want, but I'm just saying that you should consider if the looks of the synth (i.e. the C64 case) are worth the potential maintenance trouble. I stress "potential", as it all depends on your skills and other factors which I'm not familiar with. I'm not saying anything bad will happen, but this was certainly my experience with modular+DIY CS vs.PacTec+MB6582.

[fallenturtle]

12 hours ago, jjonas said:

fallenturtle, I started my MIDIbox career by making a stereo SID modular and then I made it bigger with complete control surface. My opinion on a large modular is that potentially it's a maintenance nightmare unless it's done right. I suppose you want to build it and then concentrate on making music with it rather than on maintaining it. Of course with most DIY some maintenance will be required at some point or another, but I'm sure every DIY'er knows what I mean.

A large modular can be done in various ways, and for example if you make DIN/DOUT connectios to encoders, buttons and LEDs with headers and crimp connectors (Dupont, JST etc.), that's closer to "doing it right" rather than soldering wires straight to buttons etc.; these are connections that might break if the wires move around over time when the synth is sometimes moved etc., or when you have to open the case and fix something else you are likely move the wires, and cause another problem when a soldered connection breaks somewhere. (The latter solution is what I did with my "big modular", and in my opinion that was a mistake.)

My solution was to give up the modular and build an MB6582 in a PacTec case. I think that was the right solution (for me at least). Certainly it's more boring than a DIY case and the DIY control surface that goes with it, but in my opinion it's less trouble. And of course the MB6582 CS board is not available at the moment, even though Modular Addict does say that it will be "available soon".

You choose to do what you want, but I'm just saying that you should consider if the looks of the synth (i.e. the C64 case) are worth the potential maintenance trouble. I stress "potential", as it all depends on your skills and other factors which I'm not familiar with. I'm not saying anything bad will happen, but this was certainly my experience with modular+DIY CS vs.PacTec+MB6582.

There are certainly parts of me that like the idea of going to PacTec route, but there are also some reasons that have me leaning towards the 64C case route. Part of it is nostalgia and part of it is stubbornness because I've already spent money on a couple of 64C cases to get the parts I need (want). There's also the simple control surface vs the complete... I'm leaning towards the simple because of limited space due to me because of how I'm hoping to design it (I want to mount the CS so that its coming up through the keyboard openings instead of covering and also I purchased an old VIC-20 that I'm going to cannibalize the keys from (its got the "Microgramma Extended" key caps that I adore). Of course I could also add some knobs elsewhere too. I've seen some nice looking mods people have done with C64s that are designed to use MSSIAH (and thus need the keyboard in tact).

If its not obvious I'm more of a designer than an engineer... which can lead to trouble. :)

Edited August 10, 2017 by fallenturtle

[fallenturtle]

I'm trying to decide between https://www.arrow.com/en/products/4606x-101-103lf/bourns and https://www.arrow.com/en/products/csc06a0110k0gpa/vishay for the DIN module resistor networks for the MB-6582 (Resistors R30 to R39).

The difference is the Temperature Range at Derated Power and the price. The ones that are 9 cents have a temp (C) range at derated power of 70 to 125 vs one's that are 39 cents at 25 to 150. Does it matter or can I get the cheaper ones? Thanks.

[yogi]

Pretty much go by price; unless you plan to use the synth in the Arctic or the Sahara desert :) You should be fine with either and if you need to operate in industrial temp range something else would fail first, most likely.

Yogi

[fallenturtle]

One of my goals was to try to use actual keys (from a VIC20 because I like the font) for the buttons. My issue right now is trying to figure out how to best pull this off. There's a board with the key contacts on it that attaches to the underside (close up view: https://goo.gl/photos/JnDrftzzgjEwrkT8A) and my plan is to either figure out a way to re-purpose this, or use it as a guide to create a new board to attach instead. For the encoders I founds some that are 12.5mm wide which is what I measure the cavities on the underside of hard plastic piece the keys attach to (https://goo.gl/photos/awgEwEAYyVNNRWwEA and https://goo.gl/photos/zgrzzuY3Q82vJuf88). In a perfect world I might be able to wedge them in, but I suspect I might have to do some light dremmeling to make it work. I'll need to cut out holes in various parts of the key contact board for these as well as the LCD.

What I'm hung up on is figuring out the best way to add switches for the key plunger to hit. The plungers end with a carbon pad on a rubbery flexible membrane. So I guess my goal is to find switches that don't require so much actuation force that it pierces the membrane. Worse case scenario I figure I can remove the rubber membrane and glue little hard discs to the ends of the plungers, but I'm thinking if I can pull off using the flexible membrane that will actually be less wear on the switches. The challenge to that is trying to figure out how to best mount the switches and line them up with the keys.

On the other hand, I'm wonder if I can actually cut the traces on the original contact board and re-purpose the in place contacts to trigger button signals instead. Anyone know what sorts of components I might need to do that? I'm assuming I can't just direct wire them to the mb-6582.

Keys just for trying things, not in correct order:
https://goo.gl/photos/1HNUwZq9eGMGJAyk7

Somehow with my year of looking at different midibox sid creations, I missed this guy until yesterday, who did something very similar to what I'm planning except I'm not doing a matrix and plan to have my knobs in the keyboard area:

 

Edited September 5, 2017 by fallenturtle
I reached out to Mattio who created the above MBSID and he sent me a bunch of construction pics. He took the original keyboard circuit board and used it to mount the switches to.

[Hawkeye]

Offtopic and just a remark: sometimes i got roasted when posting MBSID songs to C64 centric groups. People were claiming, that the MB6582 must be pure evil and surely has gathered lots of bad karma, because it contains SIDS from C64s, that are no more (it did not matter that i "harvested" only from otherwise dead machines and also wrote that). Posting pictures like the one above on a commodore group page is certain to cause extreme public outrage, so be prepared for that, if you want to create a similar case! :-)

Many greets,
Peter

[fallenturtle]

27 minutes ago, Hawkeye said:

Offtopic and just a remark: sometimes i got roasted when posting MBSID songs to C64 centric groups. People were claiming, that the MB6582 must be pure evil and surely has gathered lots of bad karma, because it contains SIDS from C64s, that are no more (it did not matter that i "harvested" only from otherwise dead machines and also wrote that). Posting pictures like the one above on a commodore group page is certain to cause extreme public outrage, so be prepared for that, if you want to create a similar case! :-)

Many greets,
Peter

Good to know... I assume midibox.org is safe enough. :)

[eptheca]

On 5.9.2017 at 10:03 PM, fallenturtle said:

Good to know... I assume midibox.org is safe enough. :)

Nope :(

I have had the same type of outrage here on this forum re-using old Sinclair computer cases.

arti492 wrote :  You destroyed the ZX Spectrum, you should burn in hell

Edited September 7, 2017 by eptheca
link

[fallenturtle]

On 9/7/2017 at 3:37 AM, eptheca said:

Nope :(

I have had the same type of outrage here on this forum re-using old Sinclair computer cases.

arti492 wrote :  You destroyed the ZX Spectrum, you should burn in hell

They're wrong, that's beautifully and tastefully done.

[fallenturtle]

So I've ultimately concluded that its not possible to put a MB-6582 in a C64C case while retaining the keyboard (with its PCB attached) because there's not enough vertical space at the front to fit the MB-6582's components. So I'm going to install the synth in a re-labled VIC-20 case. Since I now have an extra 64C case and a keyboard I'm also going to put together a Raspberry Pi "retro" gaming system. :)

If anyone is interested, I'm blogging/documenting my progress: http://fallenturtle.com/c64blog