C64 PSU for SID 6582

[avockley]

Like the title says, I'm planning on using the C64 power brick to power my MidiBox with 8 SID6582s. The schematic given here shows a 14v output for the SID power rail. The 6582s want 9v, instead of 14v. I think the only change that I need to make is removing the wire between pin 2 of the 7809 and the 5v rail. Is this correct? Should pin 2 of the 7809 then be connected to the GND rail? Thanks in advance for any help.

[nebula]

The schematic you link assumes the SID boards have their own regulators. You can stuff each MBHP SID board with a 7809 (6582/8580) or 7812 (6581) and they will work with the power supply schematic exactly as shown, which delivers a pretty good 14 VDC.

This is not the only approach you can take of course, but if you want to use your C64 power supply, this little circuit is the way to go for a MIDIbox SID made with discrete Core and SID modules.

Edited May 23, 2012 by nebula

[avockley]

I am designing my own circuit board with an entire MB SID on one broad, so that will not work. I just want to make the section of the power supply that outputs 14v output 9v instead. I'm pretty sure the only thing I have to do is remove the one wire and connect it to ground, but I want to make sure I don't fry my SIDs.

[baconjuice]

I think i see what it is you are after here. The problem is that the C=64 brick does not output 14 volts. It outputs 5 volts DC and 9 Volts AC, so somewhere on your circuit you will need to convert that AC voltage to DC for your sids. Does that make sense? Another option, and probably the easiest imho, is to supply your circuit with a 12V DC power supply and include both a 7805 for the core and logic chips and a 7809 (6582/8580)or 7812(6581) for the sids. Hope that helps...