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the_duckchild

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Everything posted by the_duckchild

  1. so you can hear the start up sound clearly and at full volume? That would suggest it's not the ouput circuit I would think.... hmm.
  2. there is an an entire bank of 16 resistors for the LEDs - if you use anything but red the brightness can vary a lot so 220 Ohm might not be suitable. I have white and they are way too bright i need to open it up and change them tbh! worth playing with resistor values here - higher resistance, dimmer LEDs.
  3. agreed - i used this one and it's a pretty useful thing to have... https://www.aliexpress.com/item/32847321104.html?spm=a2g0s.9042311.0.0.400f4c4dSOqlAZ
  4. I managed to get eight working chips for an MB6582 at the tail end of 2018, and they're still working (touch wood). It was not cheap. got several from these two sellers (below) on ebay which were all working fine. Took a while for them to come up though. Will let someone else comment on clones! https://www.ebay.co.uk/usr/splat79 https://www.ebay.co.uk/usr/commodore_mark1
  5. their homepage suggests otherwise now... " For the avoidance of all doubt - Modular Addict is NOT closed for good, nor do we plan on stopping any time soon.Hang tight while we right the ship, iron out the kinks, and keep John away from the splash page. ¯\_(?)_/¯More soon... "
  6. you probably want a matching pair of one or the other as they will often play together, and will sound unbalanced otherwise. Which you want is kinda personal taste really.
  7. no, I just bought the PCBs from modular addict I fortunately found someone who had a front panel left to sell. everything else was ordered based on this: http://www.midibox.org/dokuwiki/doku.php?id=wilba_mb_6582_parts_list although I had quite a lot of stuff around from other projects. It's a lot of parts though, I kept having to order things I had forgotten! Re: The Gameboy, the pic you linked is a bivert board (to increase contrast on the backlit screen by flipping the pixel polarity) You can get a replacement headphone amp for the old nintendo one (which is really noisy), but if you have a mixer it is just as easy to cut a hole in the case and put in a new headphone jack, and take the signal from before the headphone amp - the "prosound" mod. Makes the signal much clearer if you want to record it into a DAW or use it live. that's what I've done in this image: (there are actually some even better earlier points to solder to that are before the volume wheel as well (that's quite often a bit crackly as well, plus it means you can turn the speaker down whilst still having the gameboy come out of the mixer.) this is a bit off topic though ;)
  8. Just been updating my website a bit with some words and pictures about various making projects... maybe this will be inspiration? I only really started soldering things in late 2016, so totally possible to do this thing :) (you can teach an old dog new tricks it turns out) http://www.robotriddims.com/makingmusing/2020/5/20/mb6582-midibox-sid-synth
  9. that's the bit that's confused, each chip is 3 voice mono - so pairs are used to create stereo. I think it's unlikely you'll get two SID chips that sound identical no matter if they're from the same day in the same factory really, they were a bit variable to begin with and they're now 30-40 years old. 8580s are apparently a lot less varied than the 6581s though...... As long as they're in the same ballpark the differences just tend to make them sound wider (and pretty great). I don't think worrying about which year/factory they were produced in is too important (and will be difficult now anyway as the supply of them is not great!) Having said that I did try to pair mine based on the dates on them, so I get the inclination to do so!
  10. thanks, I thought I had done this, but will have another look to see if I have done it wrong somehow... I thought it was the L&R SIDS of core 1 I needed to assign the same channel. They seem to play the same pattern fine, I just can't seem to control the filter (or decay, or accent) from the knobs for one channel.
  11. Hi.... I keep having trouble understanding how to get the bassline synth working properly... all I'd like to do it get it to play the same bassline on both instruments, just so it's a bit stereo... but this seems to be beyond me a bit. Or at least... I'm trying to use the knobs to control the filter, and for some reason it only controls one of the instruments... it's very confusing as it happens even if I go in and change the assignment to "filter L+R" and it happens with multiple SID pairs, all of which have filters that work fine for other patches.... Anyone got a guess as to where I am going wrong? thanks!
  12. I'm going to let someone else answer the other Q's for certain as I didn't even get it right... but if you didn't see this as well as this thread it might help: http://www.midibox.org/dokuwiki/doku.php?id=wilba_mb_6582_psuopte Don't take this as gospel, but IIRC I don't think C13/C14 need jumpers, they were originally smoothing power so they're just between the power input and ground. Option E means they're now the other side of the voltage reg, so they're pointless, but them being missing doesn't interrupt the circuit. In fact, on that basis putting jumpers across them to ground would be bad.
  13. It's actually plugging an audio lead into the separate outs that is causing this on my build, and I'm pretty sure it's something I've caused myself rather than something inherent in option "E" as it doesn't seem to repeat on other builds. Have not attempted putting the bridge rectifier back as not really causing me any issues.
  14. thanks for checking! it's confused the hell out of me too - I wonder what on earth i've done! One day I'll have time to sit down and think about it properly I guess.
  15. i bought several from this ebay seller and all were in great condition and fully working: https://www.ebay.co.uk/usr/splat79?_trksid=p2047675.l2559 unfortunately did not see any for much less than that while I was gathering chips for an mb6582
  16. a fan is definitely pretty audible, I have passive heatsinks on my 8580s and when I asked whether I really needed the fans the general advice was "definitely not", so mine is now unplugged and just there for decorative purposes. Despite the synth being encased in foam in a flight case at the moment, no issues. I don't know about SwinSID though....
  17. The randomizer thing is good advice thanks! (I kinda feel the same tbh Oliq - I can make "normal" synth patches with it pretty well, but I am pretty sure there's some special sauce in there that it might take a lot of exploring to fully expose.) I keep meaning to play with using wavetables to switch waveform really quickly as that's the classic "make more sounds" C64 trick right? want to get my head around using Sample & Hold in the Mod matrix too, as that seems like it opens some pretty mad possibilities.
  18. argh, I feel your pain when you're so close to finished! Maybe recheck any new soldering you did do with a magnifying glass? - the 5v rail runs a LOT of places, so any changes you've made it's not impossible they're shorting something somewhere that's causing it. I definitely did this once or twice in what seemed like innocuous places. It's really easy to accidentally ground the ribbon cables for example.
  19. hmm, have to admit I am not an expert here, and the main.asm file is pretty unclear to me too, sorry! this is a probably pretty uninformed idea, but maybe another place to reflow is Q1-Q4 as I assume these are providing the clocks for the shift registers (it's not clear that they are on the schematic but I can't see what else is) and I guess that is something that might be causing the shift register to give the wrong results of button presses? I guess one of the transistors has to be another candidate as they're not too hard to blow.
  20. it sounds like you've done a bit of this, but there is a button/encoder troubleshooting guide here in case you didn't find it already: http://www.midibox.org/dokuwiki/doku.php?id=din_module and a link to a MIOS program to find shift register problems... what are the buttons doing instead of what they should? Or just not operating?
  21. good place to start thinking anyway. I think I need a good look at the schematic to understand why that would help.....
  22. ah, thanks - well that's useful to know that it is possibly just a consequence of this set up rather than something I connected I shouldn't have. When I get the chance will try and trace why it happens, but it at least seems to be a reasonably trivial issue so far.
  23. Slightly odd issue: I have a working mb6582 with this power supply set up. However if any of the separate stereo outs are plugged this disables the power switch so that whenever the 7pin DIN is plugged the synth is powered on. I assume they are somehow providing ground when plugged. If they are plugged via a ground loop destroyer then the issue is removed. Currently I just have the mb6582 plugged via a surge protected plug. I don't think this is really a very serious issue, but just thought I'd mention it in case anyone can immediately tell what I've done! It is a bit odd/annoying so eventually I will investigate properly I guess.
  24. thanks - I have 6882's, plus both airholes and passive heatsinks, so I suspect I was overdoing it a bit! fan now unplugged. I think the other issue may be that the resistors I used for the combined output socket are a bit too large - the individual outputs sound much stronger and have a better signal-to-noise ratio.
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