the_duckchild

reassuring, thanks. I'm turning it off!

Pretty sure my fan is causing a lot of noise. It's especially a bother on the drum engine it seems. I have (8) 6582 chips, all fitted with heatsinks. I'm probably going to be OK to unplug the fan aren't I? I realise no-one can say "yes" for sure, but any reassurance before I do it anyway is gratefully received.....

your build looks great btw!

Sorry Pierre, I am afraid this got snapped up already!

Because I am an idiot, when I built my MB6582, I ordered two base PCBs by mistake.. If you're in Europe (I suspect much further afield and it's not going to be worth it) and you want one, I'm happy to pass it on for the cost of postage as I don't need it. I got a lot of good advice and help one here when building mine, so would be nice to pay it forward! drop me a message if you'd like it. It's one of the modular addict ones and is untouched https://modularaddict.com/midibox-6582bs-pcb

I've been salivating over the Seq V4 too..... an addendum to the "don't do ebay" is that I couldn't find any any other way, and successfully bought multiple chips from these two sellers in the last quarter of 2018, and they do seem to find SIDs on a semi regular basis... no guarantees obviously, but they have a lot of decent feedback and I have had no issues with the ones I bought. https://www.ebay.co.uk/usr/commodore_mark1?_trksid=p2057872.m2749.l2754https://www.ebay.co.uk/usr/splat79?_trksid=p2047675.l2559

darn.... I can also tell you that I've succesfully bought from both these sellers in the last six months, who seem to regularly have SIDs for sale: https://www.ebay.co.uk/usr/commodore_mark1?_trksid=p2057872.m2749.l2754 https://www.ebay.co.uk/usr/splat79?_trksid=p2047675.l2559 and all the chips I bought are doing fine.

no expertise here really, but there seem to be quite a few on ebay around the world, and I'm not sure demand/price is high enough for people to be faking them?

I think for the original with a single chip you would just need one each of the core and SID PCBS https://modularaddict.com/midibox-sidmod-pcb and https://modularaddict.com/midibox-core8-pcb the MB6582 is a more complicated up-to-eight-chips thing with a control surface - but is really well documented... there is still a construcion walkthrough for the simple v2 thing here though: http://www.ucapps.de/index.html?page=midibox_sid.html

absolutely still viable - I started (and finished) building an MB6582 in the last few months..... Modular Addict are selling PCBs https://modularaddict.com/catalogsearch/result/?q=midibox+core although it's not mad busy on here, I still got loads of really useful help and advice on my build.

there are some conflicting values for the caps around I found - although the ones for MIDIbox SID usually seem to be the correct 22nf, I found places that said 220nf and was a bit confused (probably not but worth mentioning I thought.. I tried building a different SID project with the wrong caps and the behaviour was not far off this) That behaviour does also sound really similar to what was happening with mine when I didn't have the log flag to "On", and I was convinced it was broken..... but you've tried that. Can you try the SID in other socket of the first core? (can't actually remember if that works, but if it does it at least eliminates an issue with something around the socket)

having just finished my mb6582 in December, I can say without a shadow of a doubt "I wish you could get them for less than $20 now" ;)

thought this might be of interest to someone... https://meeblip.com/collections/our-products/products/commodore-8580-sid-chip

I suspect perhaps @jaytee is your man here as he put together a whole thread on that power supply variant.... (i'm not sure without trying to trace the power...)

something on this on the "One Power Supply" thread:

thanks! Yours is looking good! nice knobs :) I had similar issues with the buttons, they are a bit of a pain! I have to use tweezers to push them into place from the top everytime I put the faceplate on.... The LEDS were a lot less of an issue, as they sit into the holes, and are a bit further back than the buttons. Although as I had to desolder mine, they were a lot less easy the second time round, and a couple are slightly misplaced.... was so happy to have it working I couldn't face going back to fix them. Maybe one day! Good luck with the rest of it! (looks like it's on the home straight now anyway!) Had my first proper play with mine the other day, and I heartily recommend finishing it, it's such an awesome synth - so many modulation options and just the hugest sound, feels like just what I was looking for really.

ah, great thanks! to begin with I thought I had issues with some of the SIDs, but then initialised patches always sounded ok, so I assumed i'd missed something. :)

everything now seems to be working A-OK. A number of the "factory" patches I have seem to make no or very little sound as stock.... not sure if that's because they were made for v1/6581s or something? just changing the oscillator waveform usually springs them into life. The drum kits seem to be good examples of this - although initialising a drum patch seems to work just fine. Pretty sure this is all user error somehow, so am looking forward to learning what I'm doing.... anyway, just wanted to thank everyone for all the help offered, this was right on the edge of what I was confident doing and has turned out better than I could have hoped and taught me loads along the way, plus now I have a really amazing sounding synth!

Hi all, have now desoldered 100 colour cycling LEDs and replaced with single colour....... this appears to have solved the issue: no more distortion on the screen, all buttons and encoders now seem to be working fine. Not sure if it's possible or sensible to add this information to the WIKI... desoldering 100 LEDs was very boring, I'd hate for anyone else to try and be clever ;) For some reason core 4 is not being recognised at the moment, hopefully an error programming the PIC or a short/missed connection that is easily fixed. It seems I also blew some EPROMs with the reverse voltage from the screen.... otherwise all seems well now. Thanks for the advice!

Thanks... I suspect you are right on the leds.... Still, it was worth a go. Wish I could work out why they don't work! Assume it must be something to do with the matrixing circuit. I guess if the transistors were damaged I would probably have missing leds when running the test. Might just have to bite the bullet and start desoldering... Thanks again!

well, it now has 2A on the 5v rail and the same issue persists.......hmm, I guess it's worth desoldering the transistors and replacing before I desolder and replace 100 LEDs! tried the "make all the LEDs light up test from the WIKI. everything lights up fine... no colour changing, but the fast change ones actually look a different colour depending on viewing angles, which is very odd. column 7 is a slightly different colour to the rest..... can't really work out what is happening here...... I see some desoldering in my future though... Having read some of the manual I am also not convinced the buttons are all doing what they should in MidiboxSid....

it seems to boot up every time fine since I rewired all the CS connections (and got the right resistor values) though....

Hi.... hope you don't mind me asking @jaytee now have everything plugged back in. have been testing voltage at JD9 and this seems to be 5v regardless of whether the control surface is connected. Is there somewhere else I should be testing the voltage? Also, where would you suggest testing current load? I'm not quite sure where in the circuit to put the multimeter. With no Control surface connections made at all, everything seems fine. I can plug in up to JD6 working right to left, and nothing seems amiss - LCD still displays correctly, etc. When I plug in JD7 there is a flickering character on the LCD occasionally... so that's worrying. When I plug in JD8, this is where the problems really begin. The LCD starts showing distorted text, extra characters etc. The Matrix lights up, but when you select a point on the matrix it seems to leave "trails" of light leading up to the point, or just display random lights. I am wondering if the transistors here might have been damaged somehow..... I assume they are controlling the LED matrix. I don't really see how that affects the LCD - maybe it is a power issue. thanks in advance for any advice!

will do, sadly don't think I'll get to it until the weekend, but will get to it. Was just wondering out loud if there might be a way round it if this turns out to be the issue.... thanks for all the help. Sort of wish I'd just used normal LEDs now, but we'll see!

ah, great, thanks - didn't realise that about the patches Am using PSU Option "E" from this thread: so the 5v rail is coming from this - RECOM POWER R-78B5.0-1.5L SWITCHING REGULATOR, 5V, 1.5A I'm just trying to desolder the connections from the CB to the base as the way I had attached them did not leave room for the case to shut. Once I have had chance to reconnect them i will take some voltage measurements and see what's happening to the 5v rail. There are no SIDs at all in at the moment, and only three PICs, so if it is insufficient current it might be quite an issue to deal with.. but then is there any reason I couldn't use a larger switching regulator? Say this? https://uk.rs-online.com/web/p/switching-regulators/1392821/ i'm not all that learned about power supplies tbh.... would this have knock on effects on the capacitors required? I think not.... just wondering if anyone sees any obstacle!