Keeping MB-6582 PSU options "open" (quite literally!)

[Smithy]

Yes, I'm finally going to start mb-6582. :wink:

However i will like to have a choice of using PSU Options A, B, and C down the line.

Im planning on doing this by soldering SIL headers on J71, J72, J73, J74

and using pin jumpers to configure each option, (as opposed to soldering permanent bridges.)

Is it possible to stuff V1, V2, V3, V4, C13 and C14 on the board,

without them causing any problems provided the jumpers are set correctly?

Is there any other important things i have overlooked, or need to be aware of?

Any help will be thoroughly appreciated.

Edited May 4, 2010 by Smithy

[Wilba]

I heard some time ago that it's not a Good Thing to have voltage regulators with open inputs and outputs connected to voltages i.e. the voltage it's supposed to output... which would be the scenario if you switched from PSU Option A and B... option A uses the 9V DC coming from the C64 PSU and it would be connected to V2's output, V2 not being needed in option A.

It probably would make more sense to just build PSU Option B, there is little need to switch back to option A... Option B IS the "original" C64 Optimized PSU circuit that TK developed, and is just as good at supplying 9V to 6582A/8580R5 SIDs, it's just a little redundant and I think puts more load on the 5V DC supply than it needs to... i.e. PSU Option A is more optimal for 6582A/8580R5 SIDs. But if you ever want to try 6581 SIDs, you need option B.

You should probably just ignore option C and D... completely ignore option D if you are not planning to build a big case with a mains transformer, huge heatsinks and regulated 12V/9V/5V supplies. Option C is a fallback option and not fully thought out... a 5V regulator regulating 1A from 9V DC will need a heatsink that won't even fit inside a PT-10 case.

So just build option A or B. Use headers and shunts on J71, J72, J73, J74 if you like, but don't really worry about soldering parts for the other options (leave off all parts for option C, esp. V4).

[Smithy]

Thanks a lot for the reply Wilba.

Yeah ive only 6582As to my name now, so I'll probably go with option B in case i get 6581s down the line.

I was thinking it was better to use both rails alright, as the current load will be shared between both rather than just the 9V AC.

Sounds like hte thing to do!