crackling sound

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  • 01-25-2005, 05:27 AM
    hmmmm
    crackling sound
    What would cause a scratchy or crackling sound in my speakers when I use my remote to turn up the volume. It's not real loud but it does happen consistently and at all volume levels. I have a 5 month old Yamaha RX-v1400. My equipment is in another room and I'm using a "remote extender" to send the signals if it makes any difference. Thanks
    CSW Newton M60's(left right, MC500 center, Hsu VTF-2 Sub, Denon DVD2200)
  • 01-25-2005, 06:05 AM
    Resident Loser
    I know it's rude to respond to...
    ...a question with a question(actually a few of them) but, is your volume control motorized? That is, when you change the level via the remote does it actually move a control on your receiver or is it all done internally? Do you experience the same noise when the volume is changed via the Yamaha itself?

    Contingent on your further responses: If the noise occurs in both cases, it may simply be a "dirty" control...if only with the remote, it's most likely not in the audio circuits themselves per se. Perhaps the remote/extender is sending "hash" into your AC source and that is what you are hearing...

    jimHJJ(...some problems are difficult to diagnose "remotely"...)
  • 01-25-2005, 08:48 AM
    RJW1138
    Meh, I think this might be fairly common with modern receivers/amps with discrete digital volume steppings as opposed to a continuous analog control. My NAD T742 does this. Its audibility is relative to and only a fraction of the loudness of the output. When my volume's high and I change it, I do hear a very mild "crackling" sound as you said. When the volume's quieter and I change it, I can't hear this unless I put my ear right up to the speaker. It's done this from day one, so I've never been concerned that it's a problem. Just a quirk of the design. I obviously wouldn't worry about it, hmmmm, unless it's something that hasn't always happened.
  • 01-25-2005, 12:41 PM
    piece-it pete
    I second RLs' comment: it's prolly dirty.

    If you are even a little handy you might be able to clean it yourself.

    Disclaimer: If one fries ones' self it's NOT MY FAULT. (Dean, does this cover me ? lol) Unplug the unit. Don't go poking around inside the unit, particularly with a screwdriver. Electricity can be dangerous.

    OK, disclaimer over. I don't think you are an idiot, but electricity IS (or at least can be) dangerous.

    Remove the cover. Can you see the pots, the little round things the volume knob shaft goes into? If so, use the Deoxit Powerbooster you bought at Radio Shack for $15.00 with the supplied tube, look for a hole or any kind of opening in the pot, and give it a good squirt. Turn the knob up and down a good number of times. Wait ten-twenty minutes. Spray with the included Deoxit Progold, twist again, reassemble.

    While spraying the pot, try to keep from spraying circuit boards and the like as much as possible. While you're in there, clean all other pots and switches you can see. Do all the jacks on the back, and anywhere you see a metal to metal connection (like fuses, etc). Even if you don't clean the pots do the jacks, believe me.

    See if it works! This is the easiest thing, outside of changing a fuse, you can do yourself.

    If you don't see the pots (there's stuff in the way, etc), there's no opening in the pots or you don't feel comfortable with the job, take it to a serviceman and have him do it. It shouldn't be very expensive, $30-50 bucks.

    hey I just noticed it's only 5 months old. Take it to your Yamaha authorized service center (maybe call them first) and MAKE them fix it!

    Pete
  • 01-25-2005, 04:53 PM
    hmmmm
    Well, it's not mechanical so I guess RJW1138 might be on the right track. I've had this sound on my older "mechanical" volume controls and it was because of dirt. I've never heard the this sound when using the volume control on the receiver because it is in a different room. I'll see the next time a friend comes over. It sounds awesome otherwise....
  • 01-26-2005, 08:38 AM
    piece-it pete
    The noise is part of the design?!

    Not to be brutal, but that sounds like a bad design IMO.

    Pete
  • 01-26-2005, 09:15 AM
    RJW1138
    OK, I'm gonna back up and clear a few things up before I cause confusion or confrontation.

    The noise I hear when I change volume levels on my receiver is more of a quick "tick" sound than a "crackling", so sorry for the confusion. This noise was not deliberately designed into the thing, so I don't quite understand your comment "The noise is part of the design?!". I'm just saying that it's a side-effect of switching between discrete volume steps. It's not a continuum like a mechanical analog volume control. What you hear is just the effect of the signal quickly cycling through these discrete steps. It's very minor and has done this from day one, so it's not a "problem" with MY receiver. All units of this model would have the exact same attribute. Is it bad design? I would say, at this price point, not really.

    Now, is the original poster's Yamaha experiencing the same thing as my receiver, or an actual problem? I don't know! I was just offering that maybe any unit with a volume control that uses discrete steps as a opposed to an analog continuum (which is probably most stuff nowadays) could be subject to this effect, and maybe that's what's happening with his. But if his is actually a loud crackling sound, or it's something that has only started recently happening, then that's obviously not the case, and he's got an actual problem. In which case, please ignore me.
  • 01-26-2005, 10:14 AM
    piece-it pete
    RJ,

    It's OK, no problem! :D

    What I meant by "part of the design" is that if that is inherent in that system, and it was designed with that system, then in my book it's part of the design. That's all. I will admit I was surprised.

    And I understand that compromises will be made for price, no sweat. So I take it this type of control is less expensive than a motorized knob? It would be nice if pots could be done away with, no maintenence.

    Pete

    BTW, nice to meet you.
  • 01-26-2005, 10:52 AM
    RJW1138
    Alright, Pete, we cool! Nice to meet you too.

    Now, for the heck of it, here are my thoughts on the evolution of knob-related volume controls. Someone please correct me if I'm wrong:

    - First, there were plain continuous analog volume knobs. Infinitely(nearly) adjustable, but subject to becoming contaminated, resulting in crackling until properly cleaned. No remote control use.

    - Then, a motor was added to this analog knob, so that a remote control could be used to adjust the volume. The knob would actually be rotated by the motor when the volume was changed on the remote, and its mechanical analog functionality was still being used. There may have optionally been a digital readout given to indicate the volume level (in dB or some other made-up scale), but this was merely obtained by using sensor readings to determine the position of the knob. Still subject to becoming dirty and crackly.

    - Sometime after this, a completely different design was created. The volume control became digital. The knob no longer controlled an analog continuum, but rather a circuit which adjusted the volume by discrete steps. The knob no longer had an absolute position, and a motor was not needed. Using the remote to adjust volumes just accessed the circuit directly as opposed to through the knob interface, and the knob would not be automatically turned. A readout was used to display which volume step the unit was on (either in dB or some other made-up scale). This is the design currently used in the majority of audio products.

    One problem with this method is that the volume is limited to a set of finite steppings, and is not infinitely adjustable. Most units use 1 dB increments, though some may use more or less. This may or may not be satisfying.

    Another problem with this method is that because of the steppings, changes in level are pronounced. The volume circuit must be designed in such a way to smooth the transition from one level to another, and I'm assuming that some circuits do this better than others. In some cases (such as my own), this transition manifests itself as some kind of audible anomaly. In my case, I can hear a very quiet "tick" (for lack of a better word) relative to the loudness of the output. I imagine that in other designs, this problem has been better dealt with and no such anomaly can be heard.

    Does this sound about right? I'm just speculating here, but it makes sense to me. Anyways, does anyone else have experience with some kind of "audible anomaly" when changing volume? I wonder how many units do it, and how obvious or insignificant it is.

    Anyways, that's probably enough nerdery to last a while...
  • 01-26-2005, 11:36 AM
    Resident Loser
    And then there seems to be Yamaha's...
    ..."digitally regulated volume control"...which, as explained at their website, is: "a high precision digital device that controls the analog signal"...????Hmmm is right!

    They go on to claim to be using the best aspects of both technologies...While they say it regulates in "...steps of 0.05 dB..." it does so in the analog domain because "...a digitally controlled device is more accurate for balancing levels between channels..." with "...negligible gang error" but analog signal manipulation "...permits good signal resolution..."

    OK, so basically, the machine adjusts the volume...obviously some other scheme than a motorized pot...but as Pete says "...the noise is part of the design!"??? Sounds a bit creepy to me also...give me the motorized pot and a can of contact cleaner!

    At the risk of repeating myself, there would seem to be some sort of digital "hash" RFIing it's way into the analog portion of the circuitry or as P-I-P opines, it's a p!$$-poor design.

    Perhaps a $1500 aftermarket power cord is in order...maybe for the remote extender...

    jimHJJ(...but hey, that's just me...)
  • 01-26-2005, 01:36 PM
    piece-it pete
    Nerdery? $1500 cords? How about a pimpled kid wearing horn-rimmed glasses and a pocket protector while cyroing his remote lol.

    That explains the volume on a cheapie sony ht rec'r I had a while back - the volume was such big steps you could never get the volume "just right" :( . It didn't have any noise, though.

    Pete