Sid module power ? ?

MIDIbox SID
1

I am building a basic sid,6581 control A,using a 9v 500ma Dc for core (seems to work)

And 12v 150ma Dc  for sid..I’m not exactly sure where to check pins

C1:Vcc(25) - IC1:Vss(14) = 5V

IC2:Vdd(16) - IC2:Vss(8) = 5V

IC3:Vdd(16) - IC3:Vss(8) = 5V

For core,the 5v works and lcd lights up

But for sid I get wierd readings on ic’s but might be checking wrong places.

I went over parts(not many) and everything looks fine.

Could not find a link..Having trouble getting this going.

Any help would be steller!

Thanks

2

12 vdc i not enough for the sid module if you have the 7812 stuffed on it. voltage regulators lose a volt or two, not to mention the rectifier. 12vac would have been fine, or, like is suggested in the optimised psu schematic, 14vdc.

hope this helps.

3

Thanks I’ll score a 14vdc see if that does the trick 8)

wish me luck

4

I noticed in thread

SID*1 + Step A + filter (9 Sept. New feature !)  New

he uses 12v 170ma,Did He do what you said?with the 7812?

Hope it works,Won’t be able to score for  a day or so

eager!

5

the transformer that he’s using outputs 12VAC not DC. rectified to DC = 17ish Volts. transformers are cheaper to buy than PSUs, i guess that’s why he got one. i think he also wanted the PSU inside the case, so he could just run a mains cable to the box. you’ll get annoyed with having to plug in two wall warts, if that’s what you plan to do.

6

I also plan to put mine in case,Just the whole unit (the whole wall adaptore) I have installed a different plug.. Thanks for your help..i see Ac DC diference.

So look for 12 ac or 14dc? does the ma matter much what range should I stay between

Again thanks,I have been having troubles,eg.when got kit br1 on core broke(misplaced…duhh)

I am not really a noobie I’ve been circuit benting modding building kits for years (hobbie)

Searching out psu  . . . . . . . .  this may take a few moments . . .

7

each sid module pulls about 100mA, so, to be safe, i’d get a 600mA rated transformer. yeah like you say 14VDC or 12VAC wil both work.

AC transformers are cheaper.

8

1 other ?

does the amount of ma effect sound? like a larger ma cause a small hum?

Or does part on pc restrict to only ma used? (sorrry noobish)

thanks for everything

no luck yet with psu,but delayed alittle with other projects

hope to score one soon,Can’t wait to here some sounds..sequence in my beats. :o

9

the circuit will use what current it needs, no more no less, you don’t choose how much current you give a circuit. as i said before, the mA rating on the transformer is only the upper limit above which it will melt. think of it as a speed limit on a road. go above, and you’re busted.  ;D

10

Got it! but not sure if I got right power,I picked up a 12vac 0.33 amp (wallwart,psu)

Reading floating at high 11v - 12v (if I’m testing right pins?)

Don’t want to add pic’s till I’m sure on power,

Thanks Mr modnaR

11

make sure you test the transfomer’s output with the multimeter set to AC, otherwise your readings will be incorrect (on the IC socket pins, though, check with it set to DC). 12VAC going into the sid will be fine just make sure you check the IC socket pins quoted in the walkthrough before you put in the ICs, just in case!  ;D

12

I get higher than 12v off all the psu’s (transformers) when looking at midibox letteres right side up top left pin and bottom right always give me 9.05 volts? right pins? can’t find the link (net limited . .) thanks for all your help, know to test dc on pc (good to know)

13

on the sid module, you must check that:

IC1:Vdd(28) and IC1:Vss(14) has 12V if you’re using a 6581, or 9V if you’re using a 8580.

IC1:Vcc(25) - IC1:Vss(14) has 5V

IC2:Vdd(16) - IC2:Vss(8) has 5V

IC3:Vdd(16) - IC3:Vss(8) has 5V

IC1 looks like this, looking down on the IC socket:

ICs 2 and 3 look like this:

16pin.gif
16pin.gif

14

Thanks! I’m checking the right ones still only getting the 9v?

I’ll get another today a 14v dc 700ma to try again?

Maybe I have 8580 parts in (I don’t think so)

Well back at it..

Again thank you for taking the time to help me alone

It is very much helping me figure this out,

15

i built another sid kit (to be sure) I get even less,8.5v..I’m off ot get another psu..

16

what PSU were you using then? the 12V? i did say that wasn’t enough…

17

I had tried many 12v dc & ac’s (checked volt on transformer and always over 12v)used 5 different ones, Got the same not matter Ac or Dc.

Seen a 14v dc at pond shop,Now gone,So I’ll have to keep my eyes open.

Hope I can find one Monday.

18

you’ll almost always measure over 12V on a 12V trafo/psu, the fact is you need to get a trafo/ psu that is designed to output more than 12 ie get a 14VDC or a 14VAC one. it’s folly getting a 12V one and thinking that because it’s measuring 14V on the output, it’ll work. they’re manufactured to certain tolerances that allow for degradation in the voltage over time (which happens inevitably) so they build them with slightly too much voltage output to give a reasonable working life.

hope this helps.

19

  :smiley: Help! Oh yeah! I thank you for taking the time!

I hope i can get it going,my real worry is getting the mios uploaded.

Still hunting down a 14v…wish me luck

Kickn my ass I didn’t get the last one..

20

This was an interresting thread, I finished my MB SID yesterday (photos will be posted soon..) and I did only get 11v instead of 12v for the SID supply (apart from the 5v).

I decided to try it anyway and everything is working fine, except for a very annoying 50hz hum which maybe has something to do with either the low SID supply voltage or the fact that the 64 PSU I’m using is not grounded properly. Anyway, I’ll try another C64 PSU tonight.