Well I got my core all assembled (except for inserting the chips). The next step is applying power to the thing so I can test voltages. For now, I can use just some wires coming from a 9v battery, 9v 500mA AC adapter, or my C64 PSU.
What’s the long-term solution for powering the MIDIbox? I’ve found the schematics for the core and the optimized PSU, but neither make reference to any special plugs. Is it really going to be just soldered wires? Should I salvage the power plug from my C64?
Thanks!
J1 Connection to a powersupply unit (PSU). A 7V-10VAC transformer, or a wall adapter could be used. At least 500 mA is recommented, especially if a backlit display is connected, but MIDIfilter and MIDImerger work also with ca. 100 mA. AC or DC doesn’t matter, since the rectifier behind J1 converts to DC anyhow. Also the polarity has not to be taken into account.
Yep, I’ve read that paragraph many times! I have an AC adapter that fits those specs.
But what about the physical connection? J1 is two pins. The AC adapter is a cylindrical plug.
But what about the physical connection? J1 is two pins. The AC adapter is a cylindrical plug.
It seems you have three choices:
Either buy a matching cylindrical jack and wire that to J1,
Change the cylindrical connector on your power supply to a 2 pin connector to match pins at J1.
Or cut the plug off and wire the adapter directly to J1.
The connector choices are the best choices, so you can connect and disconnect your power supply.
Have Fun,
LyleHaze
Well a 9v battery worked fine for just testing the voltage across pins!
I’m going to keep looking into using the C64 power supply. Maybe use the plug and on/off switch from the C64.
I can’t find any plugs that would fit onto the two pins of the circuit board. I tried all sorts of phrases in google. What have CORE builders here done before?
I have both the 7-pin DIN sockets and the DPDT rocker switch, just like the C64. They’re new and cheap… 2 AUD each. I could probably post for 2.50 AUD.
ok, its simple, if your using a 9v wall adapter to power the core and you need to attatch to the two pins then get this lot and it will work.
http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=0448382
or for chassis mount get this
http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=0486684
then run two wires over to some molex kk crimps , crimp them up and then slide and click into a two way molex kk housing.
you need 2 way 2.54mm kk housing and some 2.54MM KK MOLEX CRIMP TERMINAL PK 100 RC at those prices you would be mad not to take them!! i bought loads off rapid. cheaper than enywhere else
there’s already a power jack included (at least) in Mike’s CORE SET ->
http://www.mikes-elektronikseite.de/shop_deutsch/index.htm
http://www.mikes-elektronikseite.de/shop_englisch/index.htm
just click on PARTS LIST / BAUTEILELISTE
or on www.uCApps.de you’ll find it with part number:
http://www.ucapps.de/mbhp/mbhp_core_orderlist.txt
edit:
for direct connection to the SIL header take a look at the following threads, the crimp connectors are available at SmashTV’s shop:
http://www.midibox.org/forum/index.php/topic,2510.0.html
Thanks guys, that’s exactly what I needed! I’ll order a few few of these options so I can have them all in front of me when I feel like making a final decision.
I have both the 7-pin DIN sockets and the DPDT rocker switch, just like the C64. They’re new and cheap… 2 AUD each. I could probably post for 2.50 AUD.
heh, I tried to salvage the power in socket and the power switch from one of my C64s with disastrous results. The C64 PSU is probably my best option, since I want to power a CORE, two 6582 modules, and eventually two more 6581 modules.
Where do you get these sockets and switches, and how do you connect the C64 PSU to the CORE and SID module J1/J2 pins? (I have the schematics, I’m wondering about physical connections…crimps/plugs/solder?)
Just curious, why are these schematics so different?
http://www.ucapps.de/mbhp/mbhp_sid_c64_psu.pdf
http://www.ucapps.de/mbhp/mbhp_8xsid_c64_psu_optimized.pdf
Is the 2 SID one obsolete now? I was going to make that one, since it’s simpler and I only have two SID modules at the moment, but I don’t want to to be obsolete when I decide to upgrade to a 4 SID setup.
There are extra capacitors on the 8xsid design. Are those found in the C64 also, or do I need to buy them separate?
Should this whole system be connected to a circuit board?
I’m going to my dad’s tomorrow to try to set up the PSU…he knows a bit more about all this stuff than I do.
One is optimized for low noise and one isn’t 
I’d go with the optimized one, even if that means buying some extra parts and a small piece of vero board.
Ah, so I do need to buy some parts. I can find most of them, but where do I get a B40C800? That’s a bridge rectifier, right? And what’s a good way to buy a single 7809?
I’ll go to Fry’s tomorrow, but their website isn’t giving me much hope that they’ll have what I need.
I’ll go to Fry’s tomorrow, but their website isn’t giving me much hope that they’ll have what I need.
Fry’s is way overpriced, Mouser is a much better option IMO.
Ah, thanks! I found those parts on Mouser, except the 7-pin DIN socket and the power switch. Anyone know where I can get those? SmashTV is out 
Another Optimized PSU question: Will it work later if I want to add a CORE and a pair of SID modules with 6581 SIDs? The 7809 in there worries me.
EDIT: ok I found two DIN sockets on Mouser, but they’re chassis mounts.
Yes it will work, please understand that you’re combining the 5v DC with the 9v AC so you end up with 14v (which is more than enough to power 6581 modules which require 12v.
Right, I get that the two voltages combine. I guess I don’t understand why there is a 7809 within the PSU circuit.
Cause 9V (from the 7809) + 5V is 14V.
