Milkmansound

I found one - Google Cache! thanks though

looks like the site is down for some reason, and I am almost done with the thing, just need the analog board schems so I can hook up the inputs and pots! always my luck - the day I choose to do a project is the one day the site is down :(

yeah, the AC line was totally shorting with the chassis. My plastic inlet does not match the inner diameter of my supply - but I will order one that does this week, and call this SID done! thanks smash - as usual, an outside opinion is the best thing for pointing out the obvious. :)

oh. Yeah. That. I will check into that tomorrow if I get a chance. I have a plastic power inlet - I sould switch to that looking at the current one, yeah - I think one side of the AC line is connected to the chassis - that would explain the mysterious 7V too - I will also check it for AC voltage. I kinda scrapped this whole thing together with stuff I just had left over from other projects, I did not even think about the metal power inlet. I will post my findings soon!

ok, I did the mod and it made some differene, but I am still getting 7VDC from the SID ground to the chassis. I think I am just going to have to live with it. my encoder has no electronic connection with the chassis, and midi is optoisolated so I should not have any problems as long as an audio cable coming out of the SID does not short against the chassis. Its a weird problem, but everything works properly so I am just gonna roll with it for the time being.

9VAC, after its rectified and regulated puts out 12VDC no problem. But now I am left with a 12VAC transformer, so that is out. that schematic looks really useful - I will send the AC to the Core only, then use a a regulator to bypass the bridge on the SID module - that might be whats causing this problem. yeah, right now the only metal on metal contact is the encoder body, but I am not even sure if its grounded to anything in circuit my AC inlet is also metal, but the wall wart itself is isloated from ground. I will change around the supply and see if I can't fix this issue - thanks guys!

when I grounded the audio out to the chassis it made the wallwart burn out - so thats out. I am thinking of lifting the ground to the audio and moving it to the chassis. like I said, I measureed 7V from the SID ground to the case ground - its just putting too much strain on the power supply.

I just put together another sid, and I am not quite sure how to get it grounded properly. Right now I am powering it off of a 9VAC wall wart, and I notice that from the audio ground to the chassis there is 7VDC, and some serious hum. Nothing is grounded to the chassis yet, except the midi jack cause I am using plastic standoffs and plastic audio input jacks. I suppose I could sheild the midi input somehow, or switch to a plastic jack - but I would like to see it done properly. here is a pic of the guts: where should I begin?

don't you find their chep animation hilarious? I used the Ucando TV repair tapes when I first started out with TV repair - they are informative, but that animation makes them really hard to take seriously.

make sure to test them all out thoroughly - I am sure you will have at least a few fully working SIDs though - nice score!

I bought 6 C64's out of 5 SIDs, 2 of mine were beat - one has a bad lowpass filter, the other was just plain messed up: unresponsive. One C64 I bought had something completely different than a SID in the SID socket, so that one was out. Hey, we are salvaging from old devices - 50% is not that bad!

those Radio Shack enclosures actually are not that bad, I have used them before. Plus, its instant gratification if they have one in stock. I am considering stuffing my SID into one too until I can afford a nicer enclosure.

well, the midines does not really need patch storage - there are no filters, no LFO's... its very very basic synthesis - what do you need to save? Its all right there - the only thing worth saving are the volume modulations and pitch stuff, but even that is not really worth it. I think the midines is a great toy to play with - its great to get as much music to pump out of the NES as possible - but its not exactly as inspiring as the SID, because its basically 2 square oscs, 1 tri osc, some noise, and a few 8 bit samples that the dude stuffed in there as a bonus. The absence of filters and LFO's make it impossible to lose that "NES" sound - which is something that I like about my midines. Listen to one of the songs I made on it, and there is no doubt that its a NES! http://www.milkmansound.com/audio/nes2.mp3

ok, maybe balanced TRS - but certainly not balanced XLR some of the old Moog synths had XLR outs, and I also recall seeing some modern "workstation" type synths with XLR - but generally, synths are not operating at mic levels and impedances - 1/4" is usually the standard. 1/4" balanced is a luxury ;)

really, there is no reason to add a balanced output at all other than to interface with already balanced gear. Most modern gear will handle a non-balanced signal though, so there is not a huge demand for an XLR output. I think every synth I own has 1/4" unbalanced outputs - having one with an XLR balanced output would actually be an inconvenience ;)

well come on man, of course the Jensen trannies are going to be that expensive. You can use a triad audio transformer - they are really nice military spec quality - and small, and will most likely handle what the SID has to offer. But you will use the super low frequencies - an opamp based balancing circuit like this for example: might be better for the project. Check this page out for even more info: http://www.dself.dsl.pipex.com/ampins/balanced/balanced.htm good luck!

nope

that would be nice - but you would get some low end rolloff. I bet the SID would sound great through a transformer though - it would add a lot of warmth!

ahh - my 2 came with the black brick type - those are much better to work with I bet - but still huge

the opamp should be able to do it - but then you are going to either need a dual supply - as in +/- n-18V or whatever the opamp takes - or something fancy to run the opamp off of a single supply. Or you can always use a nice output transformer :P

well, the SID is noisey enough on its own - but you can look at that two ways: 1 - whats a little more noise? 2 - so much noise already, more is not good! the internal rectification on the modules is not to be dismissed! I mean, I had both the core and SID modules running off of a single 9VAC supply that was rated high - so obviously, they are rectifying to DC and providing enough voltage to get the synth to operate with just a little DC power inlet in the rear - and no monster C64 psu to lug along. Man is that thing huge!!! A standard AC PSU - 9-12V should be more than enough once rectified to get the job done. Or build a PSU from scratch using that AC supply to get the 2 voltages if you want - however, there is a beefy regulator onboard each module! What is it there for if no to allow for a single AC supply????

trust me - that C64 supply with the fuse is just a heavy pain in the ass. Once you have an AC wallwart doing the job, you will be better off. BG micro has AC wallwarts rated at 1A for $2.99 - get one and play around with it, you'll never look back to the C64 supply again!

your PSU did not die - the internal fuse blew. Have fun replacing it! Its buried in plastic - I used a dremmel to get at mine, but decided to just solder a new fuse over the old one using just a little bit of the metal that I was able to uncover from the old fuse after like 15 minutes of grinding away at who knows what material. Its a real pain - and its why I am moving on to another power supply myself.

personally, I can not stand that original C64 PSU - but use what you got. If TK recommends it, then its gonna be good - however, if it dies on you, replacing that internal fuse is a hellish process. I think its better to use either a dual supply, or run the modules off a single AC supply. Or breadboard something suitable. The Sid itself is gonna make some noise no matter what you do - but minimizing ground noise is essential. I still need to figure out a solution for my single 9VAC supply for both modules, and a star ground point that makes sense.

just try a few configurations I guess, until you hear less hum. Also - what type of transformer are you using and where is it? Sometimes rotating a transformer into a new position will eliminate some hum - especially if its a torroid.