Sasha Posted January 14, 2008 Report Share Posted January 14, 2008 I`ve been thinking of making this mixer myself and will surely do once the PCB is tested and final brd available. Thanks dj3nk and lylehaze. Quote Link to comment Share on other sites More sharing options...
moogah Posted January 16, 2008 Report Share Posted January 16, 2008 Yup, quite interested in getting my hands on some PCB's for this as well :) Quote Link to comment Share on other sites More sharing options...
dj3nk Posted January 17, 2008 Report Share Posted January 17, 2008 updated layout@Lyle: Is it ok now? If yes, I'll etch a test pcb soon.greetzPS: yes its a x4 not a x8, I'll change it ^^pgav05.JPG Quote Link to comment Share on other sites More sharing options...
Goblinz Posted January 17, 2008 Report Share Posted January 17, 2008 I think I'll be building one of these too.. Gonna need something to put my MB-6582 through. G Quote Link to comment Share on other sites More sharing options...
nILS Posted January 17, 2008 Report Share Posted January 17, 2008 updated layoutHmm, there's always room for impreovemnts ;-) Quote Link to comment Share on other sites More sharing options...
lylehaze Posted January 17, 2008 Author Report Share Posted January 17, 2008 Much Better!It took me a minute to see the resistors along the SDO/SDA path, but they are there on end. The extra capacitors will really help keep the audio quiet.Looks great! Can I order one now?You mentioned X4 going to X8. That's a lot of channels.The X4 you have now will do basic volume and balance/pan for eight pairs of Audio. Or level only for 16 Mono channels.What you're showing right now (X4) is enough for my project. Of course, if you do make a bigger board, people could just mount as many chips as they need and leave the rest empty.A great way to start my day. Now it's off to shovel snow and get to work.LyleHaze Quote Link to comment Share on other sites More sharing options...
dj3nk Posted January 17, 2008 Report Share Posted January 17, 2008 OK, the layout is on foil now, but I can't find any empty pcb atm. I am sure I have some left, but wheeeeere? Gonna ask myself would be the best. lol. I hope I find them today then i could report you very soon.greetz Quote Link to comment Share on other sites More sharing options...
Sasha Posted January 17, 2008 Report Share Posted January 17, 2008 I am sure I have some left, but wheeeeere? ;D Quote Link to comment Share on other sites More sharing options...
moxi Posted January 19, 2008 Report Share Posted January 19, 2008 hi, look promising..but before you start a bench of pcb, I've read somewhere that parallel traces for audio is not a good thing, first cause two parallel traces act as a capacitor (so filtering some freq) and it's not good for channel separation..I don't know if your design with pga is concerned by such considerations, but maybe you should check that before..on the other hand, doing a pcb with no parallel traces seems to be a difficile work ... ??? Quote Link to comment Share on other sites More sharing options...
dj3nk Posted January 19, 2008 Report Share Posted January 19, 2008 the connectors are very short to the pcb and so ... thre arent long parallels ;)but thx for info anywayEDIT:I have 2 pcbs lyieng in front of me ;) tommorow ill drill the holes and perhaps ill solder the ics.greeetz :)PS: I will scan the pcb if i find my scanners driver. Quote Link to comment Share on other sites More sharing options...
DragonMaster Posted January 19, 2008 Report Share Posted January 19, 2008 I don't know if your design with pga is concerned by such considerations, but maybe you should check that before..Could be fixed if there's enough space between the traces by putting ground traces between the signal traces placed horizontally on the top. Only one side of them would be connected together, like antennas. It will absorb interference. Quote Link to comment Share on other sites More sharing options...
dj3nk Posted January 19, 2008 Report Share Posted January 19, 2008 There is a ground line between every pair of channels.I just have finished the 1st version of a xtra pcb with 8 ne5532 input buffers. If theres enough time tommorow I'll make the "mixer" pcb.My thought configuration is like this:input buffers ===> 8 stereo channels (pga1-4) ===> MainMixer ===> output I /'\ I I \./ I same 8 channels (pga5-8) ==> Mixer 2 ==> ext.FXThis way I can assign an external FX to every of the 8 incoming stereo channels indepently with wet/dry . Now my question. Is it ok to split to audio signal into 2 after the input buffers ? Or do i have to split the signal before them and use 2nd buffers for the fx tree ?greetzPS: Yes I have to change the direction of the text on the pcb ;)ne5532x8_v05.JPG Quote Link to comment Share on other sites More sharing options...
lylehaze Posted January 19, 2008 Author Report Share Posted January 19, 2008 Yes, it's best to split them after the input buffers.Just take the buffer output to both PGA inputs.In my PM I asked about what your plans were, thatwas before I read this thread. I see this now.Looks like fun!LyleHaze Quote Link to comment Share on other sites More sharing options...
dj3nk Posted January 19, 2008 Report Share Posted January 19, 2008 OK, nice to here, so I won't have to change the layout ^^.I havent programmed in asm yet. I just know a bit how it works. But I am learning C at the moment in school and hope that this will help me.Softwaresided I dont know exactly how to solve everything yet. I want to control every audio channel over 14-bit so we aren't limitated to 127 volume steps anymore. One idea is to use a cc AND a nrpn per channel,etc. to control. If the host/user isnt able to send/receive nrpn you can take cc's instead ( that way you would only have 127 steps instead of 256 ! ). Another idea is to use a cc for "channel select" and modwheel for volume. Here you wont need cc's, but you cant edit parallel volume slides within your host very easily. You'd have to change the channel@cc and volume@modwheel veryveryveryveryveryveryvery often to get hearable results.We could also implement all types of communication and could add a entry to the menu to change it if needed.other things:- Display with buttons or push-encoder (size ? functions ? )- 3 Pots per channel (Volume, pan, FX)- mute/solo buttons- headphone jack- perhaps cheap lm3915 led vu meters for ins / fx / main ( I can split a 2nd time after the input buffers, but how should I add main and fx to it ? But is it still ok to have a signal split into 4 after the ne5532 ? (Main,FX,Headphone,VU) Can I just add the same buffers again after the fx-return and mainmixer-out to get Headphone and VU without loosing quality ?? Here I'd only have to split into 2 again.any other ideas ? *g*greetz Quote Link to comment Share on other sites More sharing options...
lylehaze Posted January 19, 2008 Author Report Share Posted January 19, 2008 Wow. That's a lot going on.So far I've done it all in assembler. I wonder how hard it is to mix ASM and C int he same project?If you move up to 14 bit controls (really just 8) we'll need to re-make the log lookup tables. That's no problem, I did them in Excel anyway.The source in the WIKI is set for eight pairs of stereo right now, but it's REALLY easy to change it to 16 pairs. (I hope)If you want to build the control surface too, there's a choice to make. You can put it all one one core for a complete package, or you can build the controls on another core so you can separate them with a MIDI cable. That might be easier to work with for some jobs.Really you can do both, except that your local pots will be out of sync when you've been controlling the board remotely.Mine is controlled by sequencer, script files, a single local encoder on the mixer, and a Behringer BCR2000, all active at all times. Of course from "inside" the mixer it's one local encoder or MIDI commands. Since it really doesn't know where the MIDI is coming from. (CAMD.library)As with most projects, a display would be a good idea, just so you can see what is going on.Cool Stuff!LyleHaze Quote Link to comment Share on other sites More sharing options...
stryd_one Posted January 19, 2008 Report Share Posted January 19, 2008 I wonder how hard it is to mix ASM and C int he same project?It's pretty easy... Takes a bit of getting used to, the first time.... Trick is, putting ASM in a C project is easy, but putting C in an ASM project doesn't really work out. Quote Link to comment Share on other sites More sharing options...
lylehaze Posted January 20, 2008 Author Report Share Posted January 20, 2008 Can you suggest a good example project that mixes C and Asm?LyleHaze Quote Link to comment Share on other sites More sharing options...
dj3nk Posted January 20, 2008 Report Share Posted January 20, 2008 I read you can just use asm commands in c. but you have to put a "_" before variables. i hope thats right now what ive written. Quote Link to comment Share on other sites More sharing options...
stryd_one Posted January 20, 2008 Report Share Posted January 20, 2008 For an example project, try clockbox and analog toolbox, and this: http://www.midibox.org/dokuwiki/how_to_mix_c_and_asmdj3nk: Ahh there's a little more to it, but that is part of it. In this case, it may be best to have an include file that has the ASM functions in it... see above :) Quote Link to comment Share on other sites More sharing options...
dj3nk Posted January 25, 2008 Report Share Posted January 25, 2008 One pcb is nearly ready, just a few caps and it is fine. I have a core here too so I can test the pcb soon :) Quote Link to comment Share on other sites More sharing options...
offe Posted April 13, 2008 Report Share Posted April 13, 2008 dj3nk: Any chance of getting the pcbs? Have you finished the mixer? I got 4 PGAs but never got around to make a pcb so it would be great to have your layout./offe Quote Link to comment Share on other sites More sharing options...
dj3nk Posted April 14, 2008 Report Share Posted April 14, 2008 my pcbs are lying around and have not been tested yet. one is nearly ready soldered. but due lack of time it will last some weeks I think. Perhaps Ill find some time soon and can test them. I can give you the layout as a pdf, but it is UNTESTED (even if it "should" work)! Quote Link to comment Share on other sites More sharing options...
Sasha Posted April 15, 2008 Report Share Posted April 15, 2008 Looking forward to see the results. I would really like to build it as I don`t have any kind of mixer, and this seams like a perfect solution for me. Quote Link to comment Share on other sites More sharing options...
moogah Posted April 15, 2008 Report Share Posted April 15, 2008 +1 to that, I've been holding off on looking for a mixer until I get a chance to try this out :) Quote Link to comment Share on other sites More sharing options...
lylehaze Posted April 15, 2008 Author Report Share Posted April 15, 2008 When the prototype was hand-wired, I was having some health problems, and didn't have the time or energy to make "real" PC boards.I have a bit of time now, and have spent the last two days doing an Eagle layout for a 4311 PCB. I'm going to add a "header" board that will handle the regulators, summing amp, and the MIDIBox hookup. This header board will daisy-chain with up to eight 4311 boards for a max of 16 stereo pairs.With a little luck, I'll get these sent off to the boardhouse next week. I use a SLOW boardhouse because they are cheap, so it will be about three weeks before I can test my work.I'm adding an option for plugging in a mic-level inputs, or Phono (RIAA) inputs, or whatever. If the line level boards are well received, I'll add the others later.My eagle files will be available to anyone who wants them.I hope Smash likes them enough to take them, 'cause he can get boards made cheaper than I can.I'll be working on the documents while the boards are being made. I'll try to keep up this time, it's wasy to let plans slip.If anyone has questions or suggestions, now is the time to ask!LyleHaze Quote Link to comment Share on other sites More sharing options...
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