analog monster Posted February 24, 2012 Report Share Posted February 24, 2012 Its taking me a while but I'm building my first midibox project. I have 2 6581s and 1 8580. I'm hoping to have a stereo 6581 module and an 8580 in the same case with a single output that can either switch between the 2 types or have a mixer to blend the outputs. Can I do this with a single core? If not I will end up getting another 8580 and have dual stereo, but I'd rather not as I dont have the cash to get another SID and I'm also trying my best to complete my ongoing projects before adding new ones! Do people usually mix the two SID types in one case, and do they blend the audio output signals or have multiple outputs? Quote Link to comment Share on other sites More sharing options...
technobreath Posted February 25, 2012 Report Share Posted February 25, 2012 The way it works, one core for each two sids. The sid v2 IIRC is supporting this, and this is the current version. Now, I'm no coder at all, but my best guess is that the sid app is so complex, and already some advanced coding skills have been in work to make it to the place we are at today. The obvious solution would be to use two cores in the same box, talking to eachother, so that u have one LCD, one control surface for both of them. Remember this thing u are building is modular, so u can do a completely working two sid version and when u get the funds, u can add on the second core and the third sid. Also when more money is available, u can buy a 4th sid and have dual stereo in the end. No need to spend a the money at once if u can't afford to do so. Obviously u need a sid board for each sid also. As for outputs, u can do whatever u like. If u have electronic design skills, u can make a simple signal mixer to blend the two first sids to a mono signal, but that is lame. After all, the firmware is built for stereo. When u add a third sid, this could have its own mono output, or u can make a mixer and a pan control to blend it right in there with the stereo signal from the other two. If u have no design skill in electronics, best and most economical way is to buy a small mixer. In the end no matter how u turn this around, you will have one mono output from each sid. It's just different how people treat it afterwards. Some feed a pair of mono signals to a stereojack. Wich does nothing else than spare u of using two mono jacks. If u only have two sids, if u look logically at it, u need a stereo input to feed it to, wich is either a mixer with a stereo channel strip or two mono strips, or straight into a stereo amp. The in-box mixer really becomes interesting to have when u have more than two sids, or if the amp u are using is mono only, in that case, get another amp hehe. A mono only system is not giving it synth enough room to play hehe. In case u wonder about mixing the signals from more than two sids in-box, to build that u need a potmeter for the pan control and a handful of resistors, pluss a couple of caps. Nothing really complicated about if u know how to build it... What im saying, it would be a very basic circuit, no magics at all, but u need to know those basics before u get there. I am working on some designs for just this case, but they are not ready yet, and I have no idea when, but if u google for audio mixing circuit, u can go with the passive variant, I'm sure u will find all u need if u are able to read and design from schematics... And one last word of wisdom, the info on the mbsid, what it is, what it is not, what it can do and don't, is all on ucapps.de. Oh, and welcome, and have fun! Don't worry about it taking time to build hehe. Give itself time to do it right the first time, and plan what u are doing, so u are not doing 10 things at once, that way u have a much better chance of success the first time. Searching for errors is more pain than making sure its right the first time. Quote Link to comment Share on other sites More sharing options...
analog monster Posted February 25, 2012 Author Report Share Posted February 25, 2012 Thanks for such a definative answer. I actually am pretty confident with designing circuits, and ive a cnc milling machine for making any boards i design. There is something to be said for individual outs for each sid, but im seriously running out of space-ive all 24 inputs full on my main interface and my modular is rapidly tilling up my other 8-once theyre full thats it, no rack space for another ad/da and absolutely no more space for more racks. So im going to do twin core quad sid, 2 mono trs jack output with a switch on the front panel to choose which SID type you want to hear. So i best get my ass in gear! Thanks again Quote Link to comment Share on other sites More sharing options...
technobreath Posted February 25, 2012 Report Share Posted February 25, 2012 Sounds like you have it under control... But before u decide the outputs and switching them like that, read the manual for the sid v2, and see how that switching is done already. I am not sure myself, since I haven't yet finished mine yet. Quote Link to comment Share on other sites More sharing options...
analog monster Posted February 26, 2012 Author Report Share Posted February 26, 2012 The MB-6582 has a stereo jack per SID pair, no mixer. I prefer a pair of mono jacks to a single stereo for ease of integrating with my setup. I will eventually add a filter and MBHP_AOUT_NG. I can use the same Omron G6K-2P relay found on the SSM filter board to switch between the SID types, and with the AOUT_NG the SID type and whether the external filter is active will be saved within the patch. Its going to be a beast! Best get cracking Quote Link to comment Share on other sites More sharing options...
nILS Posted February 26, 2012 Report Share Posted February 26, 2012 You *could* run more SIDs on a single core by simply wiring them in parallel (except for the +9V/+12V on mixed "pairs"). The 74HC595 should be well able to drive 2 SIDs simultaneously. Obviously they'd be playing the exact same thing. Which might be what you want, but might also end up pretty useless since the 6581 doesn't support some of the mixed waveforms, has an entirely different sounding filter, ... So yeh, even 4 (or potentially more) SIDs per core are doable if you can live with the limitation that half of them are essentially redundant :) I'd say go to one less party, smoke 3 packs less, don't eat out once or somehow save a few bucks and get a fourth SID to make it worth the effort. Quote Link to comment Share on other sites More sharing options...
analog monster Posted February 26, 2012 Author Report Share Posted February 26, 2012 Ive done a trade with a mate for another 8580 as I will no longer need my mssiah64 cart when this is finished. I know the filters are weak on 6581s and I cant use some of the mixed waves but I like the dirtiness. `Could you clarify how I can use the shift register approach? My plan was to have all the chips playing the same anyway and the cost of a new core puts this project on the back burner - well at least it wont be entirely finished for a while Quote Link to comment Share on other sites More sharing options...
technobreath Posted February 27, 2012 Report Share Posted February 27, 2012 A second core makes it more expensive yeah... But not by thaaat much. Other than that -> what nils said. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.