freddy Posted October 7, 2003 Report Share Posted October 7, 2003 folks,I've got almost ready-built SIDs + cores, however some questions appeared;1) regarding reusing C64 PSU with 4 SIDs/4 cores, C64 delivers 9V AC according to the schematics and also according to my multimetee. the rectifier causes a drop of appr 1.4V, 7809 another voltage drop. so where do the 14V DC appear? SIDs need 12V (6581 version), rectified and smoothed from C64 PSU yields max 7V, where do we get the doubled voltage from?2) I know this doesn't matter really much, but the filtering capacitors (2.2mF and/or 1mF) should or shouldn't be seated in both SIDs and cores? since the PSU deliveres smooth 5V DC, I don't think these have to be seated in cores, but perhaps they should be seated in SIDs, although we deliver DC to the SIDs? also, there are incosistency between the SID schematic and PCB, in the schematics, there is a 2.2mF capacitor, in the PCB 1mF. where's the truth?3) regarding point (2) in mbhp_4xsid_c64_psu_optimized.pdf, 'a 7809 removes the AC part of the SID module'. does this regard only the rectifier and AC power connector? there are no more AC parts in the schematics, are there?I'm really messed up with this things, anyone can clarify? Perhaps I'm missing something, since lots of people built this and I haven't seen these questions yet...cheers,freddy Quote Link to comment Share on other sites More sharing options...
Captain_Hastings Posted October 7, 2003 Report Share Posted October 7, 2003 1) Maybe this helps to answer the question:http://www.midibox.org/cgi-bin/yabb/YaBB.cgi?board=parts_q;action=display;num=10576527942) I've used 2200µF and that seems to be ok.hope this helps Quote Link to comment Share on other sites More sharing options...
freddy Posted October 7, 2003 Author Report Share Posted October 7, 2003 one more thing regarding SID, did anyone managed to get (as much as possible) General MIDI instruments into the SID, so that they sound like GM :) ? can this be shared? Quote Link to comment Share on other sites More sharing options...
freddy Posted October 7, 2003 Author Report Share Posted October 7, 2003 Cpt, thank you very much, I must have overlooked it! Quote Link to comment Share on other sites More sharing options...
Syntax_Terror Posted October 8, 2003 Report Share Posted October 8, 2003 one more thing regarding SID, did anyone managed to get (as much as possible) General MIDI instruments into the SID, so that they sound like GM :) ? can this be shared?Hello Freddy, I don't think this is possible, and it doesn't really matter either! The nice thing about the SIDs is that it produces typical synth-sounds (saw tooth,noise,triangle,etc. waves) and not GM-sounds like piano sounds, etc.. Samples are usually used to reproduce these (wave-table) Quote Link to comment Share on other sites More sharing options...
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