renepela Posted November 12, 2009 Report Share Posted November 12, 2009 For quite a while now I have a finished and working mb6582 which I like very much. Still I'm not 100% satisfied because I hear a humm in the outputs of all sids. I think the problem is the powersupply. I was wondering if a Commodore 128 power supply is a better option. I can get one quite easy but will it help? I read the commodore 128 can handle 2.5A so it seems to me that's more than enough. Are the C64 and the C128 powersupply compatible? Or do I need to change it in some way? I know it has a different connector, but are those pins 1:1 the same? Kind regards, Rene Quote Link to comment Share on other sites More sharing options...
frailn Posted November 13, 2009 Report Share Posted November 13, 2009 (edited) It should work fine with one caveat. The C64 PSU and C128 PSU both output 5VDC and 9VAC. So, using the C128 PSU is a possibility. The caveat is that the C128 PSU has a square connector. Finding a port for that connector would be tough. They are not standard, and from what I've researched, were produced for or by Commodore just for their products. You could desolder one from an old C128 board, maybe? But, I'm not sure how it would integrate with the MB6582 baseboard. That would take some research and planning on your part. The other option is to use the C128 psu, cut off the square connector and somehow wire it to the MB6582 board or to a connector that fits a power port that works with the MB6582 board. But, with all that trouble, maybe time would be better spent tracking down the source of that hum. I have my baseboard almost complete. I tested the first SID pair with a C64 PSU and I don't detect any hum at all. My guess is that you may have a problem somewhere else on the board. Or, if it is the PSU that is the problem, you might be able to replace it with another for less hassle then hacking up a C128 PSU. Edited November 13, 2009 by frailn Quote Link to comment Share on other sites More sharing options...
Jason Milstead Posted November 14, 2009 Report Share Posted November 14, 2009 I found myself in a similar situation when I finished my MB6582 about a year ago. The C64 black brick I was using wasn't powerful enough to run the entire unit. It was outright overheating and failing after about an hour's worth of play. Fortunately, I had an old (yet easy to take apart) C128 PSU laying around. I gorilla-fisted the C64 PSU with a rather large screwdriver, hacked off the black cord and mated that to the appropriate connections inside the C128 one. Afterward, I checked for continuity between the pinouts and the newly Frankensteined PSU. Then I used my trusty multimeter to check for the correct voltages per each pin. Now I have a C128 PSU with the typical C64 round connector on the business end. No more blackouts or overheating has occurred! As a disclaimer, I am not an electrical engineer, so I'm not sure what (if any) adverse effects this could have on your MB6582 unit (Would anyone else more experienced know?). Mine works just fine but, YMMV... Here are some links to the pin arrangements of the various power supplies if you feel so inclined to try this yourself: http://www.allpinouts.org/index.php/Commodore_C64_Power_Supply http://www.allpinouts.org/index.php/Commodore_C128_Power_Supply I agree with the previous post in that the source of your hum might not be so much your power supply but what your power supply is connected to. You might be creating some kind of grounding loop either through faulty soldering on the MB6582 board itself or through your connection to your audio amplification rig (whatever you use to hear those sweet, sweet SID sounds). Try plugging in some headphones to the MB6582. If you still hear it, it's more than likely coming from inside. So, if you do hack apart an otherwise usable C128 PSU, and you still hear the hum with the headphones, than you'll know that the source is somewhere on the board itself. Good luck! -Jason Quote Link to comment Share on other sites More sharing options...
SIDsyndrome Posted November 24, 2009 Report Share Posted November 24, 2009 For quite a while now I have a finished and working mb6582 which I like very much. Still I'm not 100% satisfied because I hear a humm in the outputs of all sids. I think the problem is the powersupply. I was wondering if a Commodore 128 power supply is a better option. I can get one quite easy but will it help? I read the commodore 128 can handle 2.5A so it seems to me that's more than enough. Are the C64 and the C128 powersupply compatible? Or do I need to change it in some way? I know it has a different connector, but are those pins 1:1 the same? Kind regards, Rene Hi Rene, I can't help with the hum issue, but I ran into the problem that my only available PS was a 128. I used the same pinouts provided by Jason and bought 4-pin XLRs to handle the job - the 5-pin square connector has nothing on one of the pins. This gave me an easy solution that is strong and reliable, plus the jacks are available in panel mounts and circuit board mounts. SIDsyndrome Quote Link to comment Share on other sites More sharing options...
Wilba Posted November 25, 2009 Report Share Posted November 25, 2009 Hi Rene, I can't help with the hum issue, but I ran into the problem that my only available PS was a 128. I used the same pinouts provided by Jason and bought 4-pin XLRs to handle the job - the 5-pin square connector has nothing on one of the pins. This gave me an easy solution that is strong and reliable, plus the jacks are available in panel mounts and circuit board mounts. SIDsyndrome Can you show us what you did? Photos and/or drawings? Something like a pinout diagram would be great to help others doing the same thing. Quote Link to comment Share on other sites More sharing options...
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