Hi,
Whenever I turned the volume up on my old HiFi Amp the sound started to crackle, sometimes I lost one side of the stereofield. Since it was a very old HiFi Amp anyway I bought a new one.
A couple of weeks later the same thing happened to my new Amp, I even lose the sound completely sometimes. What can that be? Before I go buy new stuff, I would at least like to have an idea about what`s going on.
It doesn`t always happen, but often.
Any suggestions?
Thnakies,
Sandra
Speaker wire shorting out? Switch them at the amp end and see if the crackling moves to the other side. (?)
..or check using meter (continuity across pairs)
Hi Sandra,
It could be all sorts of things, but it sounds to me like a problem with speaker cables? If there's a bad connection somewhere, as the volume increases and therefore the current running through the cable, the connection will start to break down. It's possible, of course, that it's the input to the amp, but the cables carry lower voltages and current so this is less likely.
Try fitting new speaker cables and if the problem persists, swap the speakers over and see if the other side goes off. If it does, you've got a faulty speaker.
If none of this works, give us some more detail about the system and we'll think again.
ROG.
Hi rharv,
Great minds think alike?
ROG
sandra, before we bunch your skivvies, are we talking about (aboot in canadian) the same speakers? if so, i would suspect that your speakers "went south; belly up; landfill; kaput." it can fool you by seeming okay at lower volume levels. confirm it by substituting a known good pair of speakers. if that solved your problem then watch your bundestpost for mien bill. if it doesn't solve it, just take your receipts to wal-mart for a full refund.
Hi Sandra,
a quick little test to eliminate something...
Try quickly turning your volume control a dozen or so times in each direction.
Does the crackle diminish or even go away? Does the missing channel reappear? If so then I suspect the potentiometer (the device used for the volume control) is probably "grotty" - by moving it quickly you can temporarily create a clean electrical path on the Carbon track and the sliding contact(s).
Just because this is a new amp it doesn't mean that this can't happen, though it is less likely than an old one.
Other than that, as suggested, swap the speaker leads and see if the faults change channel. If they do then the problem is in the speakers or wiring, if not then the problem is internal to the amp.
lawrie, that was my first thought based on the symptoms but, she said the new amp exhibits the identical symptoms. must be bad speaker wire or fried speakers, no?
Quote:
Whenever I turned the volume up on my old HiFi Amp the sound started to crackle
Quote:
Hi,
Whenever I turned the volume up on my old HiFi Amp the sound started to crackle, sometimes I lost one side of the stereofield. Since it was a very old HiFi Amp anyway I bought a new one.
A couple of weeks later the same thing happened to my new Amp, I even lose the sound completely sometimes. What can that be? Before I go buy new stuff, I would at least like to have an idea about what`s going on.
It doesn`t always happen, but often.
Any suggestions?
Thnakies,
Sandra
Hi Sandra,
That is very likely due to the Volume Control potentiometer getting dried out and dirty. This is internal and the HiFi must be opened up to cure. The cure is to have a reputable technician introduce some Control Cleaner/Lubricant such as DEOXIT or another brand equivalent.
Common problem, easily cured, most often is worth the investment for you should be able to get years more enjoyment out of the same unit once all the controls and switches have been properly cleaned and lubed.
--Mac
Was advised by you folks to use the DEOXIT.
Using this on my Mixer input connectors, externally and
with q-tip on the internal part.
Immediately worked and resolved my problems since then,
the last few months.
You want to be careful using the product over and above items,
and not use too much. It could melt or otherwise damage finishes
and parts of PC boards.
Dont think you have radio shack in Europe, but for U.S. folks
they sell cans for about $5 U.S.
Good luck !
"Since it was a very old HiFi Amp anyway I bought a new one."
i must be missing something gentlemen. she bought a new amp! i'll stick by my speakers/wiring theory.
Agreed, the problem is in the wiring or the speakers. Switch the left and right speakers...does the problem shift to the other speaker? Doesn't necessarily mean the speaker is bad, just yet.
Check the bare wires or terminals on each end of the speaker wires....do you have good metal to metal contacts...even if tinned, scrap the terminal ends of the wire down to get good contacts.
What about the speaker contacts...are they clean and bright or corroded?
What gauge speaker wire are you using? Should be at least 16 guage, I prefer 14. Older wire will degrade sound and performance....how old are the wires?
First off: Thanks so much for your help!
I am in the process of testing what you guys suggested. Of course today everything works fine, I`m very sure though, tomorrow when I`ll be teaching it`ll appear again;-))
I thought about the wires too, since they are the same age the old amp was (hmm, I moved in in 1990 - daaamn;-)) But so are the speakers...
But to exclude the Poti theory I will plug the headphones into the amps the next time it appears again. If the crackle ain`t on the headphones it can`t be the volume poti.
I`ll let you know my testing results.
Sandra
agreed, but the language barrier may trip her up (confuse her). 16 and 14 gauge refer to AWG (American Wire Gauge) and will be totally foreign (pun intended) to her. then try to explain that 14AWG is larger (meir gross) than 16AWG. exactly opposite to what she would expect.
sandra, please explain: you bought a brand new amp? not a older, one that has been used but is "new to you?"
mac, this is reminiscent of me trying to buy ferric chloride or ammonium per-sulphate etching solution in germany. i wanted to etch my own pc boards and nary a radio shack to be found.
Don: Yes it is a brand new amp. And of course there could be a problem with it. But I think it`s very unlikely that the same symptoms appear on the old and the new amp.
Thanks for explaining the AWG thing to me, but I just would have bought any good wire. I doubt it makes that much a difference between good wire and superior wire, as long as I don`t buy cheapo crap.
Sandra
small wire introduces unwanted resistance (actually, impedance) so degrades the signal quite rapidly and is a factor of the wire's length. you can get into high finance with just the speaker wire. audiophiles (purists) would say that you need OFC (Oxygen-Free Copper) but that would be expensive overkill in your application. 16 AWG (recommended minimum) is 0.0508 inch or 1.31 mm in diameter. 14 AWG (better choice) is .0641 inch or 2.08 mm in diameter. Considerably larger. i hope that this electronics 101 lesson was helpful.
Quote:
First off: Thanks so much for your help!
I am in the process of testing what you guys suggested. Of course today everything works fine, I`m very sure though, tomorrow when I`ll be teaching it`ll appear again;-))
I thought about the wires too, since they are the same age the old amp was (hmm, I moved in in 1990 - daaamn;-)) But so are the speakers...
But to exclude the Poti theory I will plug the headphones into the amps the next time it appears again. If the crackle ain`t on the headphones it can`t be the volume poti.
I`ll let you know my testing results.
Sandra
A very sensible test procedure, Sandra - Isolation of a problem like that is how to find out where the problem is occurring.
You might also try rotating the Volume knob a wee bit as well, see if the crackling is connected to that function or not.
Record/Source switches on HiFi preamps and receivers are also notorious for becoming dry and doing the same thing, channel dropouts, scratchiness, etc. So when the problem happens again, try moving the Record/Source switch(s) back and forth a few times to mechanically clean their contacts. ALL sound must pass thru these switches.
As for the amp being new and doing the same thing, this is often a function of the environment that the device is living in. Dry air from forced air heating, dust in the air, forced air heating/cooling with inadequate filtering or filters in need of cleaning or changing, tobacco smoke, such things in the environment can cause the switches and controls to yield these kind of problems sooner than expected.
--Mac
Before you buy anything else I would follow some of the suggestions already posted. That is swap speaker wires from your left channel to your right channel. Does the problem change to the other speaker? If so your wires are bad. If not physically change speakers from the left channel to the right. Does the problem change? If yes then your speakers are bad. If not then the problem is in the amp.
Does the problem happen with everything, phono, radio, CDs, etc? Is the amp just an amp with a changer, cd player etc plugged in? Is it an all in one? Info like this could help us solve your problem.
Good luck.
I have seen repairmen just twist a knob back and forth repeatedly and got rid of pot noise . One told me it was from not moving then enough .
Quote:
I have seen repairmen just twist a knob back and forth repeatedly and got rid of pot noise . One told me it was from not moving then enough .
This trick can work well by getting a little mechanical cleaning action of the all-important contact surfaces but I must include the important caveat that if the control does not have enough of the original lubrication components left in the critical areas, it may also be a recipe for the premature wear of contact surfaces such as the carbon stripe in a potentiometer. Eventually, this could result in such wear and tear that the control will have to be replaced.
Good thing to know in a pinch, but it is highly recommended that if excercising the controls brings joy, consider it a sign that you should get the proper cleaner/lubricant inside that control as soon as conveniently possible, don't just keep doing the same thing over and over - and in most cases, without the cleaner, you will have to do that. And then one day it fails entirely...
--Mac
Well,
here I go...
I had a problem like this times ago.
Old loudspeaker boxes. In portuguese the faulty part is called "Divisor de Frequencia" (Frequency Filter is it?), a device that is mounted inside the speaker Box, with 1 or 2 potentiometers, that are able to equalise the sound. I supose it is called "crossover" in English.
Some of these potentiometers are wire resistors, high Current I supose. Well, one of my faulty loudspeaker box was with this potentiometer with some kind of problem; when volume (that is, Voltage AND current) come hight, sound crackled...
HTH
Yes, Luiz, in English that is a passive "crossover".
And, if speaker system has knobs to adjust the crossover, the wirewound potentiometers used can get just as dry and corroded as any other potentiometer, try using that DEOXIT spray on those as well. Just a wee little bit goes a long way, avoid the idea that "more is better," drenching can be a bad thing.
--Mac
Any system is only as good as the weakest link in the chain and audio systems are certainly no exception to the rule. Assuming that your music system is producing reasonably pleasant sounds, you may never stop to give it a second thought, but with a few simple tests you can check to make sure that your speakers are wired correctly and that you’re getting the best out of your system.
Attaching speakers to your Hi-Fi system usually only requires a few cables. You wouldn’t think that getting these cables mixed up would present much of a problem would you, providing your music plays back OK and no smoke comes out of the system?