Guest kotvis Posted December 19, 2002 Report Share Posted December 19, 2002 Hello there, great site en good working midibox.Later i will post my design when it's totaly finished.I have one question? I have trouble with 'jumpy' pots.If i measure the midi output, i see that my pots are 'jumpy' and not smooth. If i turn a full cycle, sometimes the output make no total range of 0-127.Often my pot jumps from 0-40/50 then smoothly increase to 90/100, but then jumps to 127 in one step.When i turn fast sometimes it doesn't skip the ends.The same problem for the sliders.My question is, is this the fact that my pots are cheap?Or maybe my core design or voltages are not good.? I've Build a Midibox 64 with 21 pots and it works fine.used pots: Conrad plastic model 2 euro? Quote Link to comment Share on other sites More sharing options...
Guest kotvis Posted December 19, 2002 Report Share Posted December 19, 2002 Hello there, great site en good working midibox.Later i will post my design when it's totaly finished.I have one question? I have trouble with 'jumpy' pots.If i measure the midi output, i see that my pots are 'jumpy' and not smooth. If i turn a full cycle, sometimes the output make no total range of 0-127.Often my pot jumps from 0-40/50 then smoothly increase to 90/100, but then jumps to 127 in one step.When i turn fast sometimes it doesn't skip the ends.The same problem for the sliders.My question is, is this the fact that my pots are cheap?Or maybe my core design or voltages are not good.? I've Build a Midibox 64 with 21 pots and it works fine.used pots: Conrad plastic model 2 euro? Quote Link to comment Share on other sites More sharing options...
TK. Posted December 20, 2002 Report Share Posted December 20, 2002 Did you buy linear or logarithmic pots/faders? (Part-Number?)Because based on your description it seems that these are the log ones and they are not accurate for the MIDIbox :-/Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
TK. Posted December 20, 2002 Report Share Posted December 20, 2002 Did you buy linear or logarithmic pots/faders? (Part-Number?)Because based on your description it seems that these are the log ones and they are not accurate for the MIDIbox :-/Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
Guest kotvis Posted December 21, 2002 Report Share Posted December 21, 2002 Thorsten,I've examined the pots and i reconized an 'a'.My father told me that an 'a' stands for linear.He said that an 'b' should be logarithmic.Is this right? So yes, what's wrong with my box.?Greetz, Richard Quote Link to comment Share on other sites More sharing options...
Guest kotvis Posted December 21, 2002 Report Share Posted December 21, 2002 Thorsten,I've examined the pots and i reconized an 'a'.My father told me that an 'a' stands for linear.He said that an 'b' should be logarithmic.Is this right? So yes, what's wrong with my box.?Greetz, Richard Quote Link to comment Share on other sites More sharing options...
Guest the_Swede Posted December 21, 2002 Report Share Posted December 21, 2002 There are different standards, some manufacturers use 'a' for linear and 'b' for logarithmic, others do it the other way round. Probably just to for the hell of it I suppose. Anyhow, the easiest way of ascertaining what kind you have is to apply a voltage (say, 5V) over the pot and measuring voltage from one pin to the other. When the pot is halfway and it is linear both resistors should have equal resistance and you would measure 2,5V (or half of whatever you chose to apply), otherwise not. Quote Link to comment Share on other sites More sharing options...
Guest the_Swede Posted December 21, 2002 Report Share Posted December 21, 2002 There are different standards, some manufacturers use 'a' for linear and 'b' for logarithmic, others do it the other way round. Probably just to for the hell of it I suppose. Anyhow, the easiest way of ascertaining what kind you have is to apply a voltage (say, 5V) over the pot and measuring voltage from one pin to the other. When the pot is halfway and it is linear both resistors should have equal resistance and you would measure 2,5V (or half of whatever you chose to apply), otherwise not. Quote Link to comment Share on other sites More sharing options...
LO Posted December 22, 2002 Report Share Posted December 22, 2002 yeah or just set ya multimeter to Resistance and measure the pot (using the center pin & 1 other) @ the Mid & max/min points should be around 50% at the 1/2 way mark Quote Link to comment Share on other sites More sharing options...
LO Posted December 22, 2002 Report Share Posted December 22, 2002 yeah or just set ya multimeter to Resistance and measure the pot (using the center pin & 1 other) @ the Mid & max/min points should be around 50% at the 1/2 way mark Quote Link to comment Share on other sites More sharing options...
Guest kotvis Posted January 1, 2003 Report Share Posted January 1, 2003 Hi there, i've measured my pots.The strange thing is that i don't see a very linear curve in my obtained results :-/ The first quarter goes slowely with low voltage. In the center it gets quicker? But it felt linear at the overall. I did buy an 'lin' type. I checked my conrad-order. Can i fix my problem with a resistor or something else to increase my voltage curve at the end of my pots??I don't like to buy other/new pots! It's an expensive hobby i know. But it's a hell of a job to wire all these damn pots! Quote Link to comment Share on other sites More sharing options...
Guest kotvis Posted January 1, 2003 Report Share Posted January 1, 2003 Hi there, i've measured my pots.The strange thing is that i don't see a very linear curve in my obtained results :-/ The first quarter goes slowely with low voltage. In the center it gets quicker? But it felt linear at the overall. I did buy an 'lin' type. I checked my conrad-order. Can i fix my problem with a resistor or something else to increase my voltage curve at the end of my pots??I don't like to buy other/new pots! It's an expensive hobby i know. But it's a hell of a job to wire all these damn pots! Quote Link to comment Share on other sites More sharing options...
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