m00dawg

Making a control surface the modular way is a good idea. These days being able to laser cut and 3D print things might also be options to consider. Those weren't nearly so readily available when MidiBox first started and the MBSID is one of the oldest MidiBox designs. Speaking of modular though, Modular Addict sells the MB6582 base and CS boards. I know you mentioned only wanting 2 SIDs, but it's still something to consider. You only need to populate what you want to use and can also use things like ARMSIDs. My own MB6582 is just that, 2 6582's and 2 ARMSIDs. The wiki has the build information so while it's not a small project, it's doable. The main thing is having that full control surface already made and designed makes using the synth soooo much easier.

This is more MIdiBox adjacent since it's more chiptune. I've been very active working on my native tracker for the Commander X16 65C02 based modern 8-bit computer. Though it is still alpha (mostly because the file format may change still), it's quite usable. I've been working on a demo-tune to show at least some of the capabilities: Folks that want to know more can join the band this Friday at 8pm CST where I'll be doing a show and tell of DreamTracker and answering questions. I can even dig into the code if anyone is interested. We're doing it through Bandcamp which requires an RSVP (though the event is free) so folks can sign up here: https://victimcache.bandcamp.com/merch/dreamtracker-showcase-bandcamp-friday

That's absolutely glorious Peter! Nice work (as always!)

I'm liking mine! Though I will admit I use the real SIDs more often. I still haven't sorted out why the right channel doesn't always work (only for real SIDs and it doesn't matter which ones) in half my MB6582 sockets. I have the real SIDs in channel 3. ARMSIDs are in 1. Side by side, I still notice a lot more interesting stereo affects using the real SIDs. But the ARMSIDs are certainly cleaner and clearer.

Nice looking great! Congrats!

Thanks! The main vox was done by my bandmate. He's arguably the "front-man" but you can hear me way in the back on the choruses :)

We finally released a new song! It's a cover and mostly showcases more of my Eurorack and things, but the MB6582 makes an appearance with it's juicy filtered squares:

Both the 4922 and 525 use SPI though yeah? 525 has more channels though certainly. Going SMD there's options for 8 channels even. It's good point though I hadn't though if/how SPI works on the MidiBox platform and which pins are available for the chip-select. My Mutant Brain has 4 CVs along with 12 triggers, which is usually plenty for me, though designing something with a few more CVs could be nice. I had thought of how I might go about making a base module (which houses the uC) and then having modules you can add which have an addition DAC and Op-amp and perhaps some sort of shift-register to provide a set of gates with it too. Good point about the receiver though, I hadn't thought of that. Actually I think I could just mount that whole module to the back of the case and call it good? And/or the MIDI in/out's if I can internally route them over to the CV modules. I'll have to look again at all the Midiphy options there as I know they're fairly numerous!

I've been looking at MIDI -> CV again. While I like the Mutant Brain Eurorack module (and Polyend's MIDI->CV looks amazing), I built my own custom expandable case (which by the way is available in kit form for those interested) and am looking at some of the modules that have external I/O and seeing what I can do to route those to the back. Having a MIDI cable always connected to the front of my rack feels out of place, and it gets in the way where it can just live along the back of the rack (that's where the power is already). Mutable Instruments' CVPal, along with some others, use the MCP4822 chip. It's 2 channel but has an internal voltage reference and it's 1/3rd the price of the MAX525. Buying 2 still is only 2/3rd's the price of a 525. The CVPal has a calibration procedure, similar to what I was thinking. I was actually going to use a LUT for all the notes so each note has a specific calibrated value (CVPal tests at the first and 7th notes of the octave to derive offsets). Anyways I'm flying off the rails a bit I guess. The point was, curious why no AOUT_4822 exists since that seems like a favorable option to the AOUT_LC? For my application, I'll probably end up on a Teensy and using the Arduino platform but the MBCV project has _a ton_ more going for it by comparison (though it doesn't easily fit inside a Eurorack format I don't think?)

Ah good deal! I wasn't sure if sharing the direct BINs (as opposed to the C64 PRGs) was allowed but Martin was kind enough to send me those for directly programming it from the Arduino Shield. Hindsight, using a shield is a lot easier I'm sure but the breadboard method did work. I got it setup just in time too as my SSM2144 Eurorack filter (the Electrosmith) came in so I could finally mess around with some bassline patches (albeit not in stereo as I only have 1 filter). Both the ARM2SID and my 8580 pair sounded pretty great with a VCA and the filter. The real SIDs have a bit more "charm" but being 8580's, the ARM2SID has a really nice filter emulation by comparison. Not as good as my actual 6581 but I know if I cough too close to that thing it'll die :P and it's awfully noisy compared to the ARM2SID. Most of this has already been discussed above so I'm just rehashing what's known. For the filter though, yeah it works! Since I am not using AOUT I have to control the Eurorack bits via a MIDI CV (Mutant Brain) but it's not too bad to mess around. The one thing I did seem to notice is the ADSR bug seems faithfully replicated and/or I haven't found a way to properly sync the drums and turning the ADSR bug workaround off/on does have an affect. Not having to mess with that would be nice but it's not the worst. I can (and have) just sampled the drums directly it just takes more effort. Apart from the initial setup bumps, that's my only "gripe" and I use quotes because it's sorta unfair to complain about such an issue when it's faithful to the original! I expect I'll populate my MB6582 with at least one more ARM2SID pair. I think that'll be a good balance (4 8580's, 4 ARMSIDs)

Update to the above, yep, I contacted Martin and it did indeed require using the Beta firmware. I flashed the chip, popped it in and now I have delicious stereo SID pair goodness!

Ah yep good call. I wasn't sure if it was a quick fix. I'm worried it's something with the cable connections but when I ran wires to the 2nd socket (I did all that on a breadboard), both SIDs were detected. Though it could be firmware - I'm noticing it'll do stereo if the filter isn't involved. I gotta say, since I have 8580's (well I have one precious 6581 from my actual C64), I forgot how deep the filter is on the 6581's. Turn it to 6581 mode was quite a treat!

My ARM2SID arrived today yay! And I have to say it DOES sound good for being an emulation. Only trouble is, despite verifying ARMSID is setup in socket mode, as soon as I put on a patch that has different settings between L/R (such as a Bassline patch), audio drops out on the SID socket and I only here occasional clicks and crackles from that. I've tried swapping L/R in the app (I'm using minicom with the Arduino Tester program), SID emulation modes, tried swapping which socket the main chip is in, tried moving them both to another pair of sockets in the 6582, tried switching the direction of the included molex cable, but nothing seems to fix it. Anyone else run into this issue?

I feel like I need to defend SID's filter a little here. You mentioned subjectivity and I think that easily applies to the SID filters - or any filter for that matter. The SID filter is what it is. I'm not sure any filter is better or worse. My OB-6 sounds BEAUTIFUL but it in now way sounds remotely close to a SID, never will. I have Seppoman's boards and a few SSM2044 chips ready for whenever I finally get around to building an AOUT module and the audio demos of the SID + 2044 sound glorious! But I'd also argue, it sounds a lot less SID-like. Sounds sort of like its own synth in its own right, perhaps as it should. But it doesn't replace SID's quirky filter. I love it for what it is, not what it isn't.

Well I grabbed up an ARMSID dual socket. I've spent a few days messing about with my MB6582. I was getting some odd crackle on one of the channels but only after it had been warm-ed up for a while. Since I don't use it in 8 SID monster mode all that often, I decided to pair it down to 2 real SIDs. But I'd still like to have another pair to play with drums and things or a bassline. I was just getting nervous hearing about the supply of SID dwindling I thought I'd better not needlessly have them sitting there largely doing nothing. I'm looking forward to it! Anyone know of the ARMSID avoids the ADSR bug (as in might drums be easier to use?)