Midibox SID V2 power supply

MIDIbox SID
1

Hi,

I am about to start building a new Midibox SID V2. But before I start I need to clear some points, and specifically related to the power supply of the Midibox SID.

I have bought the kits from SmashTV and the PCBs are : Core is CORE_R4D, and SID is R3A.

All the questions are related to the document : mbhp_8xsid_c64_psu_optimized.pdf.

  • You specify for the power main circuit to use a B40C800. Is it equivalent to a W08G ?

  • You show in the schema to remove the regulators on the core module (7805), is it the only thing to remove ? I mean nothing else is to remove for the supply part on each core module ? As I am using the kits from SmashTV there is a regulator and a bridge rectifier on each core module, so do I need to connect them ? If not what connections do I have to make ?

  • You show also a connection between the core modules on J11 connector where VS and MI from the master core module goes in each slave module also on VS and MI. Is it correct ? I mean shouldn’t it be VS and M O from the master core that goes in each slave on VS and MI ?

  • Now for the SID modules power supply. You show to use a 7809 regulator on the main supply circuit. Does this mean that we also have to remove it from each SID module as for the core modules ? If so, do I have to make a bridge between IN and OUT+ as for the core modules ? And same question as for the core module, for the bridge regulator, do I need to connect it and if not what connection do I have to make ?

  • Again for the SID parts, you connect each Vd pin of the SID modules to the 14VDC pin of the power circuit. But where do I connect the Vs pin of the SID modules ?

Thank you very much for your help.

Best regards from France  :smiley:

Germain

2

  • W08G will work.

  • You will not have to stuff the rectifiers and the 7805 on the cores (a jumper wire between pins 1 and 3 of the vreg are a nice idea, as to have the 2200u cap connected) - oh lookey you now have some rectifiers left over that you can use for the optimized PSU :wink:

  • MI/MO, nope that’s correct, all MIDI Ins are connected in parallel

  • 7809: You leave those in. Also you’d want to leave the rectifier in cause it doesn’t hurt and is a nice little insurance policy :wink:

  • Vs connections: Look at the .pdf - on the SID modules it’s J2:Vs (bottom left pin)

3

Hi,

Thank you so much for your fast answer !  :smiley:

  • W08G will work. –> OK, perfect.

  • You will not have to stuff the rectifiers and the 7805 on the cores (a jumper wire between pins 1 and 3 of the vreg are a nice idea, as to have the 2200u cap connected) - oh lookey you now have some rectifiers left over that you can use for the optimized PSU –> Great ! That was exactly my idea  :slight_smile:

  • MI/MO, nope that’s correct, all MIDI Ins are connected in parallel –> OK

  • 7809: You leave those in. Also you’d want to leave the rectifier in cause it doesn’t hurt and is a nice little insurance policy  –> OK

  • Vs connections: Look at the .pdf - on the SID modules it’s J2:Vs (bottom left pin) –> Humm, I am afraid I don’t understand. Does this mean that Vs of connector J1 of SID module is wired to the Vs of connector J2 ? Does this means that Vs of connector J1 is not to be connected at all ?

Thank you so much !

Best regards

Germain

4

Hi,

I have one last question regarding your answer :

For Vs connection on SID modules. Does this mean that Vs of connector J1 of SID module is wired to the Vs of connector J2 ? Does this means that Vs of connector J1 is not to be connected at all ?

Thank you and best regards  :smiley:

Germain

5

Does this means that Vs of connector J1 is not to be connected at all ?

Correct. Simple answer to all your questions:

Everyhing that needs to be wired is in the pdf. If it’s not in there, don’t wire it.

6

Thank you very much !

You answered all my questions.  :smiley:

Best regards from France !  :wink:

Germain