dj3nk Posted December 29, 2007 Report Share Posted December 29, 2007 Hi people, if there is anybody how wants to build a MB Mixer here is something I've got for you. If you are interested in this layout just let me know. If its OK for LyleHaze I'll add this to the wiki.;D greetz ;D 4311.JPG Link to comment Share on other sites More sharing options...
Ashiman Posted December 29, 2007 Report Share Posted December 29, 2007 some people still dont get the basic idea : PGA series are STEPPED ATTENUATORS. MAN WTF YOU THINK WHY "ZERO CROSSING DETECTION" IS THERE? Link to comment Share on other sites More sharing options...
dj3nk Posted December 29, 2007 Author Report Share Posted December 29, 2007 and what is so bad about this ? 31.5 db in 0.5 db steps are 64 voulume settings. It's enough for me since i dont want to do any volume slides with it. or do i dont know somethin else what is mattering ? and what is that zero crossing detecting ? i also wondered what that pin is for. Link to comment Share on other sites More sharing options...
Ashiman Posted December 29, 2007 Report Share Posted December 29, 2007 please try to think about it , what happens if you got a nice sine wave , and you start to attenuate back & forth , totally out of sync!! Thats right, a CLICKS& POPS ! Inside there is resistor ladder, like in other digital pots resolution is limited. Try to read those digipot threads, and you get whats the problem. You have to spend effort to fight off crosstalk. This layout offers itself for crosstalk big time . Typical mixer application is something like - overdriving the signal adding second and other harmonics, PGA is totally transparent, its usually employed as preamp before ampllification. Link to comment Share on other sites More sharing options...
dj3nk Posted December 29, 2007 Author Report Share Posted December 29, 2007 hmm that sinewave issue is a good explanation. but i just need it to mix several stereo line signals into one stereo signal. It should be connected between my synthezisers and the audio input of my soundcard. every time every channel is on by default. sometimes BETWEEN parts I could change the volume and/or pan. So I wouldnt have to expect any clicks in my example or do I ?thank you for your help Link to comment Share on other sites More sharing options...
Ashiman Posted December 29, 2007 Report Share Posted December 29, 2007 Midi controlled mixers never catched on . What you propose I dont see much use either. You can feed the soundcard with -10dB signal and not loose any precision, then if you already talkin about PC, why dont just do it once you ' re inside ? I would just wait for the AOUT guys, once they have VCA you re set and you can build your mixer with generic parts, and the sort of with the distortion you want plus you can fade it as you wish. Link to comment Share on other sites More sharing options...
lylehaze Posted January 10, 2008 Report Share Posted January 10, 2008 Yes, of course you can add it to the WIKI!Also, the PGA chips have a range from +31.5dB to -95.5dBin 0.5 dB steps, so that's actually 255 separate levelsplus MUTE.Since I'm using CC7 for control, I only have 127 activelevels (plus MUTE), but the additional resolution isused by the LOG conversion for smoother final resolution.I hope that helps,LyleHaze Link to comment Share on other sites More sharing options...
dj3nk Posted January 11, 2008 Author Report Share Posted January 11, 2008 :Dplease use that thread from now on for the discussion of this pcbhttp://www.midibox.org/forum/index.php/topic,7280.msg79516.html#new*THREAD CLOSED* Link to comment Share on other sites More sharing options...
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