Spiug31 Posted April 22, 2009 Report Share Posted April 22, 2009 What is it that generates a pop/crackle sound when a stepped attenuator traverses steps ? this is happening with my left channel goldpoint stereo volume attenuator, the matching right attennuator in the same amp is unafflicted by this odd effect. One differance I can see between the two attenuators is that the unaffected one has wires linking to chassis ground (xlr pin1) other wise they seem to be wired the same. left -pop/crackle right - no pop/crackle n.b. the loudness of the pop/crackle generated when traversing steps increases as the attenuator knob is turned further clockwise. While on a step both attenuators perform the same. The actual volume of the pop/crackle remains far below the volume of the music presented by the next step of the attenuator. do these pop/crackles mean any damage is being done ? Quote Link to comment Share on other sites More sharing options...
postjack Posted April 22, 2009 Report Share Posted April 22, 2009 pot demon(s). Quote Link to comment Share on other sites More sharing options...
Voltron Posted April 22, 2009 Report Share Posted April 22, 2009 pot demon(s). I've had those before, but not i/r/t gear. Quote Link to comment Share on other sites More sharing options...
manaox2 Posted April 22, 2009 Report Share Posted April 22, 2009 Is it just me or do those joints not look so good? I would reflow some of those as they are not so shiny or smooth as I think they should be. Quote Link to comment Share on other sites More sharing options...
Spiug31 Posted April 22, 2009 Author Report Share Posted April 22, 2009 I've had those before, but not i/r/t gear. what is i/r/t ? Quote Link to comment Share on other sites More sharing options...
grawk Posted April 22, 2009 Report Share Posted April 22, 2009 in regards to Quote Link to comment Share on other sites More sharing options...
Dusty Chalk Posted April 22, 2009 Report Share Posted April 22, 2009 Serious answer: dirt. The impedance is fluctuating wildly when you turn it, so it needs cleaning or replacing. Quote Link to comment Share on other sites More sharing options...
cetoole Posted April 22, 2009 Report Share Posted April 22, 2009 More likely contact bounce. Quote Link to comment Share on other sites More sharing options...
Spiug31 Posted April 22, 2009 Author Report Share Posted April 22, 2009 from Goldpoint - Attenuator Types 24 position, "make-before-break" thick hard-gold contacts on PC boards for minimum switch bounce. but contact bounce seems quite possible as the pop/crackle happens only for a short time with the music taking its place within a fifth of a second if the knob is left positioned between firm steps. Quote Link to comment Share on other sites More sharing options...
luvdunhill Posted April 22, 2009 Report Share Posted April 22, 2009 try adding a parallel resistor from the wiper (i.e. output of the pot) to ground see if that fixes the problem. Quote Link to comment Share on other sites More sharing options...
Dusty Chalk Posted April 22, 2009 Report Share Posted April 22, 2009 More likely contact bounce.Well yeah, considering I wasn't paying attention and had assumed it was a continuous style attenuator. Quote Link to comment Share on other sites More sharing options...
Smeggy Posted April 22, 2009 Report Share Posted April 22, 2009 We are in your pot making noise Quote Link to comment Share on other sites More sharing options...
Spiug31 Posted April 22, 2009 Author Report Share Posted April 22, 2009 Quote Link to comment Share on other sites More sharing options...
Spiug31 Posted April 22, 2009 Author Report Share Posted April 22, 2009 Is it just me or do those joints not look so good? I would reflow some of those as they are not so shiny or smooth as I think they should be. try adding a parallel resistor from the wiper (i.e. output of the pot) to ground see if that fixes the problem. If it isn`t a symptom of something badly wrong I`m happy enough to leave it as is and enjoy the music The theory of contact bounce eases my mind enough. first time I`ve used multiquote, very useful Quote Link to comment Share on other sites More sharing options...
Looser101 Posted April 23, 2009 Report Share Posted April 23, 2009 Could be DC offset from your source, as well. Switch Right and Left inputs and see if it switches sides. Quote Link to comment Share on other sites More sharing options...
Spiug31 Posted April 23, 2009 Author Report Share Posted April 23, 2009 Could be DC offset from your source, as well. Switch Right and Left inputs and see if it switches sides. done and the left attenuator retains its pop, so no change Quote Link to comment Share on other sites More sharing options...
HeadphoneAddict Posted April 23, 2009 Report Share Posted April 23, 2009 Could be DC offset from your source, as well. Switch Right and Left inputs and see if it switches sides. That was a good guess though, because my Goldpoint will do that with my iMod if I don't use DC blocking caps between the iMod and volume pot. Quote Link to comment Share on other sites More sharing options...
digger945 Posted April 23, 2009 Report Share Posted April 23, 2009 This happened on mine till I connected the left and right signal grounds. Quote Link to comment Share on other sites More sharing options...
thrice Posted April 23, 2009 Report Share Posted April 23, 2009 Is it just me or do those joints not look so good? I would reflow some of those as they are not so shiny or smooth as I think they should be. I use lead free solder, that can make it look like its a cold joint. Quote Link to comment Share on other sites More sharing options...
Looser101 Posted April 23, 2009 Report Share Posted April 23, 2009 I use lead free solder, that can make it look like its a cold joint. If people would just stop licking solder joints you could just use the good stuff. Quote Link to comment Share on other sites More sharing options...
manaox2 Posted April 23, 2009 Report Share Posted April 23, 2009 I use lead free solder, that can make it look like its a cold joint. Got it. I blame lead solder fumes for me being this way. Quote Link to comment Share on other sites More sharing options...
n_maher Posted April 23, 2009 Report Share Posted April 23, 2009 I use lead free solder, that can make it look like its a cold joint. Yup, I have some copper solder that looks the same way when the joint cools. I'm tempted to blame the switch but the fact is that there may be nothing really wrong. A call or email to Goldpoint might be worthwhile. Quote Link to comment Share on other sites More sharing options...
Pars Posted April 23, 2009 Report Share Posted April 23, 2009 If it were me, I would wire the left one up like the right with the additional grounds. If that didn't work, I would swap L and R attenuators to see if the problem moved or not. Quote Link to comment Share on other sites More sharing options...
Spiug31 Posted April 24, 2009 Author Report Share Posted April 24, 2009 If it were me, I would wire the left one up like the right with the additional grounds. done but no effect: ran a wire from an xlr pin 1 to the ground strut on the left attenuator no change in pop/crackle behaviour. If that didn't work, I would swap L and R attenuators to see if the problem moved or not. unbinding the attenuators from the chassis to do a full physical swap isn`t something I`ll undertake and I don`t think the right attenuators` hot and cold audio input wires are long enough to reach. If however I can get a pair (or ideally two pairs) of 2 pin extension cables 26"+ long then I`d be willing to try making the swaps via those. -offtopic- I see a new smilie has appeared Quote Link to comment Share on other sites More sharing options...
Pars Posted April 24, 2009 Report Share Posted April 24, 2009 done but no effect: ran a wire from an xlr pin 1 to the ground strut on the left attenuator no change in pop/crackle behaviour. unbinding the attenuators from the chassis to do a full physical swap isn`t something I`ll undertake and I don`t think the right attenuators` hot and cold audio input wires are long enough to reach. If however I can get a pair (or ideally two pairs) of 2 pin extension cables 26"+ long then I`d be willing to try making the swaps via those. -offtopic- I see a new smilie has appeared From your pics I couldn't see al the connections to determine how big of pain in the ass this would be to do. Of course its easy to sit here and say I'd do it Quote Link to comment Share on other sites More sharing options...
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