rogic Posted March 21, 2003 Report Share Posted March 21, 2003 Hi,I have problems with jittering; Connected 16 pots to MB64, and when I finish moving pots, I let MB alone and after some 10 secs, last CC changed start jittering. Not much at all, something like:105106105106105106So it only jitters a little; Not a real problem with applications but it can be pain in the ass if you want to use 'learn' function of host application. In some cases this doesn't occur at all, but I was not able to figure out the reason why. Dynamic jitter filter doesn't fix this. Pots are on 25 cm cables to AIN, and connected 'starlike', like shown on Tor Arne's site. Pots are 10K.Is there any rule or something for grounding unused pot inputs of the AIN, or any other tip regarding this? Thanx. Quote Link to comment Share on other sites More sharing options...
d2k Posted March 21, 2003 Report Share Posted March 21, 2003 Is there any rule or something for grounding unused pot inputs of the AIN, or any other tip regarding this? Thanx.Yes! From AIN PDF:if you leave out a 4051, clamp the appr. analog input (J5:A0, ... J5:A3) to ground!Also, if ur only using 1 AIN module clamp unused pins of J6 on the core (what the AIN goes to) to ground as well...Best...Dan Quote Link to comment Share on other sites More sharing options...
rogic Posted March 21, 2003 Author Report Share Posted March 21, 2003 I've done all that... if I haven't done it, my midiox monitor screen will be filled within a second. Quote Link to comment Share on other sites More sharing options...
jerash Posted March 22, 2003 Report Share Posted March 22, 2003 Pots are on 25 cm cables to AIN, and connected 'starlike', like shown on Tor Arne's site. Pots are 10Khello,I'm on the way to solder my 64 pots... and wondered about the StarLike cabling for 0-5V.There's only one connection on AINx4 modules (J7), so one wire would go to the first pot and then make a bride to the second, then to the third ???If someone could provide a picture of a working cabling, i'd apreciate :)thanks, RAF Quote Link to comment Share on other sites More sharing options...
d2k Posted March 22, 2003 Report Share Posted March 22, 2003 Hey RAFThis is the pic from the walkthrough on the site...HTHDan Quote Link to comment Share on other sites More sharing options...
jerash Posted March 22, 2003 Report Share Posted March 22, 2003 thanks thorsten, but i'd previously seen this picture. In fact i meant a "Photography" :-[Because As i see in this picture (drawing) it's like there is a lot of cables leaving the ainx4.would someone open his MB and take a detailed photo ?sorry for the mess.raf Quote Link to comment Share on other sites More sharing options...
jerash Posted March 22, 2003 Report Share Posted March 22, 2003 what confuses me is the term "8 pots in a bundle"I don't see how i could connect only 8 pots together while there is only 1 0-5V out on the ainx4.i hope its clear enoughRAf Quote Link to comment Share on other sites More sharing options...
TK. Posted March 22, 2003 Report Share Posted March 22, 2003 Problem is that I don't know how to visualize it better.Let's take a look under my MB64 case:;-)Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
rogic Posted March 25, 2003 Author Report Share Posted March 25, 2003 This is all great guys, but you haven't told me what to do about jittering :-/Should I shorten cables? Try to move them as far as I can from Power Supply? Any hint? Quote Link to comment Share on other sites More sharing options...
Ian_Hurlock Posted March 26, 2003 Report Share Posted March 26, 2003 How smooth is your PS. Got some fat cat caps on him ?Ian Quote Link to comment Share on other sites More sharing options...
rogic Posted March 27, 2003 Author Report Share Posted March 27, 2003 Hi,my MB64 differs from others - PS is on another board and 5V is delivered to the CORE from circuit with 7805, etc. Capacitor is 25v 3300uF, and the voltage to the CORE varies from 5.02-5.03V. Is this ok?Another thing: I selected 'snapshot at power on' in vmidibox; When I monitor in midiox messages sent by MB on startup, I receive this: TIMESTAMP IN PORT STATUS DATA1 DATA2 CHAN NOTE EVENT 13621 GMe -- 176 0 89 1 --- CC: Bank MSB 13621 GMe -- 176 1 98 1 --- CC: Modulation 13621 GMe -- 176 3 92 1 --- Control Change 13621 GMe -- 176 4 91 1 --- CC: Foot Controller 13621 GMe -- 176 5 55 1 --- CC: Portamento Time 13621 GMe -- 176 6 26 1 --- CC: Data Entry MSB 13621 GMe -- 176 7 43 1 --- CC: Volume 13621 GMe -- 176 9 47 1 --- Control Change 13621 GMe -- 176 10 105 1 --- CC: PAN 13631 GMe -- 176 11 83 1 --- CC: Expression 13631 GMe -- 176 12 71 1 --- Control Change 13631 GMe -- 176 13 28 1 --- Control Change 13631 GMe -- 176 14 11 1 --- Control Change 13631 GMe -- 176 15 0 1 --- Control Change 13631 GMe -- 176 16 86 1 --- Control Change 13631 GMe -- 176 17 0 1 --- Control Change 13631 GMe -- 176 18 0 1 --- Control Change 13631 GMe -- 176 19 0 1 --- Control Change 13631 GMe -- 176 20 0 1 --- Control Change 13641 GMe -- 176 21 0 1 --- CC: 21 (E-MU) 13641 GMe -- 176 22 0 1 --- CC: 22 (E-MU) 13641 GMe -- 176 23 0 1 --- CC: 23 (E-MU) 13641 GMe -- 176 24 0 1 --- CC: 24 (E-MU) 13641 GMe -- 176 25 0 1 --- Control Change 13641 GMe -- 176 26 0 1 --- Control Change 13641 GMe -- 176 27 0 1 --- Control Change 13641 GMe -- 176 28 0 1 --- Control Change 13641 GMe -- 176 29 0 1 --- Control Change 13651 GMe -- 176 30 0 1 --- Control Change 13651 GMe -- 176 31 0 1 --- Control Change Why I don't get states of pots #2 & #8 ???? Quote Link to comment Share on other sites More sharing options...
TK. Posted March 28, 2003 Report Share Posted March 28, 2003 It seems that this is a bug in the "snapshot after power-on" feature. It has been implemented on a very dirty way - possibly values will not be sent when the saved pot positions were the same like the current positions. I will check this with the next release...The voltage level is superb! It would be interesting if you also notice jitter when you increase or decrease the input voltage to the voltage regulator (@J1! -- I don't mean the 5V behind the voltage regulator). Does your PSU allow to vary the voltage?Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
rogic Posted March 28, 2003 Author Report Share Posted March 28, 2003 Thanks TK for the reply; This snapshot 'bug' is not so important for me - two pots not sending their state is not a problem at all, I just thought it may have something to do with jittering... but that's a total electronics newbie assumption.About voltage: you suggest that I change voltage after 7805? I'll go to my friend (an expert - not dummy like me! :)) and try this idea...thanks a lot Quote Link to comment Share on other sites More sharing options...
d2k Posted March 28, 2003 Report Share Posted March 28, 2003 Hey RogicAbout voltage: you suggest that I change voltage after 7805? Before the voltage regulator (7805), so from J1... the 2 pins (J2) behind the 7805 are a +5v output, that could for instance, be used to power another core in a multicosre setup - details on this are on the core page on the site...Some wallplugs allow u to vary the voltage, from say 7.5v-12v via a trim pot on the plug itself - I'm assuming T means this...BestDan Quote Link to comment Share on other sites More sharing options...
rogic Posted March 28, 2003 Author Report Share Posted March 28, 2003 you mean to amplify voltage before 7805? Quote Link to comment Share on other sites More sharing options...
TK. Posted March 29, 2003 Report Share Posted March 29, 2003 Hi Rogic,yes --- very important --- the PIC supply voltage should never exceed 5V, thats the job of the 7805, it limits (and regulates) the voltage to this levelBest Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
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