scratchy noise in one channel
brody05
Posts: 329
:(Haven't heard this noise before any idea's greatly appreciated.
There is an intermittent noise that sounds like someone dragging a needle on a record player accross a couple of tracks that lasts for about a second and can happen three times in a minute or ten minutes apart coming from one of the speakers my power amp runs.
It is the only thing switched on and goes to the other speaker if I swap the cable around. Otherwise it is working as it should. I have checked and rechecked my conections and can't find anything obvious.
Please help
There is an intermittent noise that sounds like someone dragging a needle on a record player accross a couple of tracks that lasts for about a second and can happen three times in a minute or ten minutes apart coming from one of the speakers my power amp runs.
It is the only thing switched on and goes to the other speaker if I swap the cable around. Otherwise it is working as it should. I have checked and rechecked my conections and can't find anything obvious.
Please help
Post edited by brody05 on
Comments
-
Probably a dirty pot.
What gear are you using?"He who fights with monsters should look to it that he himself does not become a monster. And when you gaze long into an abyss the abyss also gazes into you." Friedrich Nietzsche -
It is the only thing switched on and goes to the other speaker if I swap the cable around.
Please elaborate on this. -
You have a bad cable.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
Please elaborate on this.
Thank you for the reply's
The power amp is the only thing switched on, ie pre amp dvd ect all off.
The gear is:
Denon AVCA1se pre amp (running sides and rears and centers)
Verastarr 6.4 (running stereo and SDA array's and subs on SRT's)
SRT control unit
Polk SRT's fronts
Polk RT3000's rear
Polk RT1000p sides
Polk FX55i's centers
Have been running the amp pretty hard the last hour or more to see if warming it up has any difference, I doubt the noise will damage the speakers as I have heard it many times today and they are fine, it is not loud and not changed by increasing or decreasing the volume at all.
Forgive my ignorance, what does dirty pots mean???
Cheers -
You have a bad cable.
It goes to the other speakers when speaker cable at amp end changed so I guess your meaning the RCA's, I can certainly check my soldering job on them. I did have to make some up for the new set up so it is certainly a possibility.
Thanks -
Thank you for the reply's
The power amp is the only thing switched on, ie pre amp dvd ect all off.
The gear is:
Denon AVCA1se pre amp (running sides and rears and centers)
Verastarr 6.4 (running stereo and SDA array's and subs on SRT's)
SRT control unit
Polk SRT's fronts
Polk RT3000's rear
Polk RT1000p sides
Polk FX55i's centers
Have been running the amp pretty hard the last hour or more to see if warming it up has any difference, I doubt the noise will damage the speakers as I have heard it many times today and they are fine, it is not loud and not changed by increasing or decreasing the volume at all.
Forgive my ignorance, what does dirty pots mean???
Cheers
The biggest clue is that the noise is always the same volume.
The volume knob is a little piece of metal that slides along another one. If the contact between them is dirty, it will cause static. If this was true, turning the volume knob around will cause the static instantly. Try it.
It is possible that it is the amp, but there's no easy way to track down the problem since it is intermittent. -
It goes to the other speakers when speaker cable at amp end changed so I guess your meaning the RCA's
You're not very clear with your descriptions, but I hope you don't have RCA terminations on your speaker cables.
Again, you have a bad cable. Now, whether it's a bad solder job or something else, you'll have to figure that one out.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
You're not very clear with your descriptions, but I hope you don't have RCA terminations on your speaker cables.
Again, you have a bad cable. Now, whether it's a bad solder job or something else, you'll have to figure that one out.
Sorry, maybe a difference in some terms between the US and NZ.
I was meaning the soldering job on the RCA cables that go from the pre amp (Denon) to the Verastarr as I had to cut an RCA cable in half and put new RCA plugs on each end. Got one of them a bit hot as it was the first time I had done any soldering of that nature for some years now.
I am using banana plugs for the speaker cable and have the speaker wire soldered into them but cant see that being an issue as when swapping the cables from one speaker to another it doesn't stay with that cable, it does stay with that channel on the amp though.
Could an RCA cable if the cause even if it is not carrying a signal to the Verastarr cause a noise like that, ie I wonder if it needs to have a signal running through it to cause a problem.
I did try spade plugs to start with on the speaker cable end and clamped down the terminals quite hard to ensure they didn't move as there is not much room inbetween terminals before changing to the banana plugs, I wonder if I overtightened it loosening the conection into the amp itself.
So many possibilities, but it hasn't done it for over an hour now, the amp is warm - could be related perhaps.
Thanks -
The biggest clue is that the noise is always the same volume.
The volume knob is a little piece of metal that slides along another one. If the contact between them is dirty, it will cause static. If this was true, turning the volume knob around will cause the static instantly. Try it.
It is possible that it is the amp, but there's no easy way to track down the problem since it is intermittent.
Tried it and no change, and yes, no easy way. Just plan on running it and see if it gets worse, I have removed and replaced the cables and the amp is warm now, haven't heard it for a while so maybe fingers crossed it has resolved itself????:o
Cheers for the help. -
I am using banana plugs for the speaker cable and have the speaker wire soldered into them but cant see that being an issue as when swapping the cables from one speaker to another it doesn't stay with that cable, it does stay with that channel on the amp though.
Ah ok, that's not what I understood you to say in your previous posts. Since the noise stays with the same channel even with the pre amp off/disconnected then your problem is most likely with the amp. The sound you describe would seem to indicate a bad solder joint, possibly with the binding post connection or some other area on one of the other boards. You'll have to visually inspect the joints looking for a dull solder joint. A good joint will be shiny.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
_________________________________________________
***\\\\\........................... My Audio Journey ............................./////***
2008 & 2010 Football Pool WINNER
SOPAThank God for different opinions. Imagine the world if we all wanted the same woman -
Ah ok, that's not what I understood you to say in your previous posts. Since the noise stays with the same channel even with the pre amp off/disconnected then your problem is most likely with the amp. The sound you describe would seem to indicate a bad solder joint, possibly with the binding post connection or some other area on one of the other boards. You'll have to visually inspect the joints looking for a dull solder joint. A good joint will be shiny.
English is my second language, gibberish is my first (particularly when theres bourbon flowing)
If it is the amp then it goes away when it is warm, will check again in morning once cool again and see if it comes back. If not maybe the cables were an issue as I have rewired the lot, or it will get worse to the point of being able to figure it out.
It certainly is performing exceptionally well as I have pushed it pretty hard today without issue. Sounds great, even finetuned the set up to the point of getting much better imaging.........
Cheers -
If the cable is bad, wiggling it with the amp turned on would tell you. Also make sure you try the amp with no wires to it except the speaker cables and power cord. If you have spare RCA connectors, you can solder a small wire and short out the pin to the ring. This is called a muting plug and is used to mute the input of an amp.
Do you have any other new electronics or appliances? Mini fridge, perhaps?
Otherwise, it's probably the amp itself.
edit: Goes away when warm? That's not necessarily a good thing. -
.....there's bourbon flowing........up to the point of getting much better imaging.........
Amazing. I get exactly the same effect._________________________________________________
***\\\\\........................... My Audio Journey ............................./////***
2008 & 2010 Football Pool WINNER
SOPAThank God for different opinions. Imagine the world if we all wanted the same woman -
Yeah wiggled all the cables but couldn't find anything to produce the noise.
Also tried the amp with no imputs connected but by this time it had stopped doing it, as above will try again tomorow.
Hadn't heard of that (muting plug), if it comes back will try it tomorow.
Nothing else new, just changed power sources around a bit as I wanted an individual power point for the verastarr but only had two in that area so I ran an extension to the area to run some of the other equipment there such as TV, tuner, DVD ect.
Will post more tomorow and let you know how I get on if it does re-appear. The outer box was pretty badly damaged and quite obviously the amp had been dropped on its way over here so something loose could be an answer.
Thanks for the input and idea's.
Mike at Verastarr and Bob the guy that builds the amps have also been emailing, very prompt responses and helpful. I cant help but be impressed with the level of after sales follow up not to mention the amp itself. Will be posting a 'review' once I have the set up just right and the time. -
If it is the amp then it goes away when it is warm
That's exactly what would happen with a bad solder joint. When the amp is cold there is intermittent contact, when it warms up the solder joint expands making full contact.
Ricardo is on a roll tonight...LOLPolitical Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
That's exactly what would happen with a bad solder joint. When the amp is cold there is intermittent contact, when it warms up the solder joint expands making full contact.
Ricardo is on a roll tonight...LOL
Will have a good idea in the morning once cool and start the testing process again.
Some good news though, Fedex will cover the costs of getting it back to the US for repair and back to me again when done. I suppose it better for that then them paying out on it...... -
-
Well it cooled overnight and has been on for an hour or more and hasn't done it again.
Intermittent problems............arghhhhhh..........so frustrating.............
What to do next????
-
Pick up the amp while it's on, and start rocking it back and forth.
Did the problem dissapear since swapping cables? Maybe you already fixed the problem. -
Pick up the amp while it's on, and start rocking it back and forth.
Did the problem dissapear since swapping cables? Maybe you already fixed the problem.
It's a bit hard with the cables plugged into it in the rack and that it weighs 35kgs but I gave it a bit of shake as best I could and didn't notice it happen although it wasn't much of a shake due to above limitations.
Gut feeling at this stage after so much testing is that it isn't a cable problem as it would have to be the output speaker cable and they are all new with soldered ends and I didn't do anyting to them other than unplug them and put them back in, that and that jiggling and wiggling them didn't reproduce it either.
Maybe just the way the terminals are contacting/connecting to the output board and something loose from the drop on the way over, the box was pretty badly damaged and quite obviously had been dropped from a reasonable height.
At this stage we are thinking that replacing the input and output boards is the safe bet, be a shame to send it all the way back to the US and not cover our bases so to speak.
Thanks for the suggestion. -
turn volume down OR turn amp OFF then turn the dials back and forth FAST like your playing FOOZBALL sometimes that cleans up those issue, if your amp has been around dust or sitting awhile sometimes you can turn back and forth the dials (volume right left etc) and hear it make that nosie but it usually goes away after a few VILOENT turns
-
ALSO good speaker wire is key. ALSO IMPORTANT... make sure you paid your electric bill
-
ALSO good speaker wire is key. ALSO IMPORTANT... make sure you paid your electric bill
Yes, paying the bill however painfull needs be done.
The power amp doesn't have a volume and as it does it without the preamp on and the various testing I have done not likely related but I did try to produce the noise by leaving them all on and turning the volume dial.
Part of the problem trying to find this noise is as the SRT owners know, any sound in the left channel is reproduced in various forms in both the stereo and SDA array on the left speaker and the SDA array on the right speaker, so one channel's issue comes through on 3 channels in the speakers themselves, I did run cable direct to the stereo array from the 2nd channel on the amp and got it to do it so narrowed it down in the end but more fluffing around really.
I am using straightwire Chorus II speaker cable, not sure how it rates over there but we dont have the options you guys have, I have always been pretty fond of Straightwire, I like the way it sounds after making comparisons with others we had available here and haven't had problems with it, here is a link to what I have, feel free to rate it, I know there is better, only thing I dont like is trying to get 12/4g cable into banana plugs, thats why I had to solder it in, too much cable to get into them;
http://www.thecableco.com/product.php?id=4831 -
Well it cooled overnight and has been on for an hour or more and hasn't done it again.
Then sit back and enjoy the music.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
Then sit back and enjoy the music.
Just about to, the wife and one year old are heading out, reference level here I come........ -
Just fired it up and it's back.........
Going to have to send the amp back to the US for repair
-
Well the amp has been sent back to the US for repair.:(
Fedex have actually been very good to deal with, they are sending it priority both ways, paying for the cost of repair up to the insured value and sending it back priority to ensure I have it back in 3 weeks as Bob at AB amps is going to turn it around within a week of recieving it.
As hard as it was to pack it up after falling in love so quickly I know it will come back in 100% working order (fingers crossed it doesn't get dropped again haha).
It never did it when it was warm, left it on for days and didn't hear it once so certainly only did it cold or coldish.
Some clever people had already said that so awesome and thanks for all the help. I look forward to getting it back and doing a review on it, early indications are 'what an amp, the best multichannel amp I have heard'.
Had the chance to play around with the set up and I managed to get the imaging sorted, phase right, bass and tone levels all good and the new drivers getting run in, just got better and better, then had to pack it up.
Will keep you updated on its progress.
Bob at AB amps has been sensational, very prompt to answer emails, happy to help with the Fedex side of things, over and above any and all expectations. He does the building and repairs of the Verastarr amps and it is reasuring to know it is going to someone who cares about what they do.
Can you tell I am impressed???
