pop/crackle sound when a stepped attenuator traverses steps ?

[Spiug31]

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 ?

[postjack]

pot demon(s).

[Voltron]

pot demon(s).

I've had those before, but not i/r/t gear.

[manaox2]

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.

[Spiug31]

I've had those before, but not i/r/t gear.

what is i/r/t ?

[grawk]

in regards to

[Dusty Chalk]

Serious answer: dirt. The impedance is fluctuating wildly when you turn it, so it needs cleaning or replacing.

[cetoole]

More likely contact bounce.

[Spiug31]

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.

[luvdunhill]

try adding a parallel resistor from the wiper (i.e. output of the pot) to ground see if that fixes the problem.

[Dusty Chalk]

More likely contact bounce.

Well yeah, considering I wasn't paying attention and had assumed it was a continuous style attenuator.

[Smeggy]

We are in your pot making noise

[Spiug31]

[Spiug31]

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

[Looser101]

Could be DC offset from your source, as well. Switch Right and Left inputs and see if it switches sides.

[Spiug31]

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

[HeadphoneAddict]

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.

[digger945]

This happened on mine till I connected the left and right signal grounds.

[thrice]

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.

[Looser101]

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.

[manaox2]

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.

[n_maher]

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.

[Pars]

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.

[Spiug31]

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

[Pars]

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