# A high-pitched cycling whine with my Audison LrX5.1k



## Hoot (Jan 18, 2008)

Love this amp - everything about it except for the cycling wine.

Here is the deal: Amp has some sort of internal output problem related to RCAs. Why do we know this? Isolated from the install on the test bench, with speaker wired connected, there is still a whining problem. In the install, we could sometimes get the amp to stop whining with a movement of the RCA wires, but right now it is whining all the time.

The whine: It is high-pitched and constant; the pitch of the whine cycles... whheeeeeeeeeeoooooooowwwwwwwwweeeeeeeeooooooo. Turn up the amp way loud and you can drown out the whine obviously, but it is loud enough that even at moderate volumes it is wrecking my musical enjoyment -- lots of sound-deadening in my Audi.

Again, very sure this is the amp, and not an alternator problem -- no problems with other amps in the same vehicle either and, again, problem with the amp was isolated on the test bench.

Went through Audison tech service USA (Youseff and Larry), and had little success -- they said they didn't find a problem and sent it back to me without calling and asking questions (had my phone #, etc.). I won't bad-mouth them (nice guys), but they didn't service the amp as it should have been, and I won't use them again if I don't have to. 

United Audio won't work on Audison, and so I am unsure of who to turn to. Any thoughts or recommendations appreciated. Anyone have an idea what might be going on with this amp???

Many thanks, in advance....


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## Hoot (Jan 18, 2008)

Any ideas on shops/technicians who'll work on ANY mobile amplifier? Good and/or bad? thanks....


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## cmayer (Oct 2, 2008)

i was having the same problem w/ my memphis 4 channel and it ended up bein bad rcas


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## Hoot (Jan 18, 2008)

Thanks for the post; meant to say all RCA cables had been been replaced in the vehicle. Again, problem was isolated on test bench. I need a good amp repair shop.


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## envisionelec (Dec 14, 2005)

Hoot said:


> Love this amp - everything about it except for the cycling wine.
> 
> Here is the deal: Amp has some sort of internal output problem related to RCAs. Why do we know this? Isolated from the install on the test bench, with speaker wired connected, there is still a whining problem. In the install, we could sometimes get the amp to stop whining with a movement of the RCA wires, but right now it is whining all the time.
> 
> ...



Love the description. Yeah, it's a noise indicative of a lifted input ground connection. The input "doesn't know what to do"/has a VERY high input impedance and will pick up as much radiated energy as possible - including emissions from the power supply (what you're probably hearing).

I have zero problem working on Audison amps - but you have to find a good shop...they have very delicate PCB copper.

However, I have zero time to do it (sorry). I'm sure there has to be someone that will chime in soon.


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## Hoot (Jan 18, 2008)

Many thanks, envisionelec. That is a bit comforting to hear somewhat both knowledgeable and confident about the source of the problem.

I will continue to bump with hopes of finding a good recommendation; thanks, again.


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## subwoofery (Nov 9, 2008)

Try Steve Mantz from Zed Audio. Who knows, he might work on it. 

Kelvin


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## ace956 (Aug 28, 2009)

Hoot said:


> Love this amp - everything about it except for the cycling wine.
> 
> Here is the deal: Amp has some sort of internal output problem related to RCAs. Why do we know this? Isolated from the install on the test bench, with speaker wired connected, there is still a whining problem. In the install, we could sometimes get the amp to stop whining with a movement of the RCA wires, but right now it is whining all the time.
> 
> ...


Hoot,
I may take your audison in for repair but first i want you try a couple of things. have you tried plugging cables into the inputs and short the pin and ground on both channels, basically shorting the inputs. does this reduce the whine. then, while the cables are plugged in and shorted, short them to battery ground. let me know how each of these effects the whine. btw make sure the rca cable is as short as you can get.

thanks, ace956


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## Hoot (Jan 18, 2008)

Ace, thanks so much for your thoughts. I sent you a PM. Can you help me understand what exactly you mean/what I should do? Sorry, not an electronics guy, here. Anyone else, if Ace is off celebrating the Labor Day weekend?

Thanks, all!


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## ace956 (Aug 28, 2009)

Hoot said:


> Ace, thanks so much for your thoughts. I sent you a PM. Can you help me understand what exactly you mean/what I should do? Sorry, not an electronics guy, here. Anyone else, if Ace is off celebrating the Labor Day weekend?
> 
> Thanks, all!


Hoot,
Hey Mike, I have been calling you and leaving messages. I am home tonight and Monday the 6th. If you want you can call me my number is 916 988 0406. Hope to hear from you.


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## envisionelec (Dec 14, 2005)

Hoot said:


> Ace, thanks so much for your thoughts. I sent you a PM. Can you help me understand what exactly you mean/what I should do? Sorry, not an electronics guy, here. Anyone else, if Ace is off celebrating the Labor Day weekend?
> 
> Thanks, all!


I think he means take a piece of wire from battery ground (not battery B+!!) and short it over to the RCA input shield. It should quiet the whine if the input trace is lifted.


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## usacimember (Dec 24, 2009)

They did have an issue with that particular amp when it was first released. It was a very small amount of them, but I personally did encounter it. Have Elettromedia replace it if it's still under warranty. They need to send it back to Italy.


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## Hoot (Jan 18, 2008)

envisionelec said:


> I think he means take a piece of wire from battery ground (not battery B+!!) and short it over to the RCA input shield. It should quiet the whine if the input trace is lifted.


Envisionelec, quiet the whine or silence it? 

Ace and I finally spoke on the phone (thanks, Ace!), and yesterday I finally got around to removing my rear seat where the amp is grounded to the chassis of the car. I got a long pair of RCAs from storage and replaced the RCAs connected to the H/U and then touched the other end to the bolt that connects the power ground to the car. Actually, I tried this with all 3 input pairs (high/mid/sub - running 3-way). 

In each case the whine was quieted, though not eliminated.

By the way, this amp is not under warranty. Usacimember, that is a bummer about the fact that this was a known problem; particularly, since Elletromedia (AudisonUSA) sent it back to me telling me there was no problem. I had to deal with a guy in California faxing him bs paperwork (they didn't apparently reference it), and then ship the amp to Minnesota for the actual repair (3rd-party repair). 5-6 weeks later my amp came back to me unrepaired; they shipped it back for free, but I paid $30 to ship it them, and waited all that time for nothing.

Ship to Italy???


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## envisionelec (Dec 14, 2005)

Hoot said:


> Envisionelec, quiet the whine or silence it?
> 
> Ace and I finally spoke on the phone (thanks, Ace!), and yesterday I finally got around to removing my rear seat where the amp is grounded to the chassis of the car. I got a long pair of RCAs from storage and replaced the RCAs connected to the H/U and then touched the other end to the bolt that connects the power ground to the car. Actually, I tried this with all 3 input pairs (high/mid/sub - running 3-way).
> 
> ...


Right - it quiets it because there is a slight voltage drop in the resistance between Battery ground and the input ground. The whine can only get quieter and is a great troubleshooting method for the problem I detailed above.

I feel your pain, so against my better judgment, I'll fix the amplifier for $35 if you pay shipping both ways. I'll have it about a week. 

I'll send you a PM with the shipping details. Please wrap it in bubble wrap and don't use packing peanuts. 

Aaron


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## Hoot (Jan 18, 2008)

*RCAs*

To clarify, I removed the RCAs from the inputs on the amp. From the amp I ran my test RCAs to where the amp was grounded to the car; again, this resulted in significantly reduced noise/whine, though trace noise still existed. Come to think of it, the "cycling whine" pretty much stopped - the sound that remained was just like soft static.

Does this help anyone with diagnosis? Lifted input ground? Ideas for repair?

Many thanks to all - you've been wonderfully helpful.

~Hoot


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## Hoot (Jan 18, 2008)

We posted at the same time, Aaron. Look for a PM, and thanks.


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## envisionelec (Dec 14, 2005)

*Re: RCAs*



Hoot said:


> To clarify, I removed the RCAs from the inputs on the amp. From the amp I ran my test RCAs to where the amp was grounded to the car; again, this resulted in significantly reduced noise/whine, though trace noise still existed. Come to think of it, the "cycling whine" pretty much stopped - the sound that remained was just like soft static.
> 
> Does this help anyone with diagnosis? Lifted input ground? Ideas for repair?
> 
> ...


Yes, my interpretation of the problem remains the same. I understood what you did. Hope to see the amp soon.

Cheers,
Aaron


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## ace956 (Aug 28, 2009)

Hoot said:


> Envisionelec, quiet the whine or silence it?
> 
> Ace and I finally spoke on the phone (thanks, Ace!), and yesterday I finally got around to removing my rear seat where the amp is grounded to the chassis of the car. I got a long pair of RCAs from storage and replaced the RCAs connected to the H/U and then touched the other end to the bolt that connects the power ground to the car. Actually, I tried this with all 3 input pairs (high/mid/sub - running 3-way).
> 
> ...


Hoot,
we are making progress. I should have told you to try this before but can you just connect a wire to battery ground to the ground on the rca inputs and see if the noise reduces. the test you already did is telling us that when you short the input and then ground it the noise goes away. the reason it doesn't go away completely is because you never grounded all channels at the same time. if just grounding the rca jack input has the same effect then we need to, if you feel comfortable doing this, pull the cover off the amp and solder a wire from battery ground in the amp to all rca input grounds. you can run 1 wire from batteryground to one pair of jacks the from that jack to the next and so on.

thanks ace956

i tried ti find your phone # on your old email but i couldnt find it. if you can give it to me i will call you and talk you through this better or call me.

wade


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## envisionelec (Dec 14, 2005)

ace956 said:


> Hoot,
> we are making progress. I should have told you to try this before but can you just connect a wire to battery ground to the ground on the rca inputs and see if the noise reduces. the test you already did is telling us that when you short the input and then ground it the noise goes away. the reason it doesn't go away completely is because you never grounded all channels at the same time. if just grounding the rca jack input has the same effect then we need to, if you feel comfortable doing this, pull the cover off the amp and solder a wire from battery ground in the amp to all rca input grounds. you can run 1 wire from batteryground to one pair of jacks the from that jack to the next and so on.
> 
> thanks ace956
> ...


No confidence or do you just not read thread responses?


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## ace956 (Aug 28, 2009)

envisionelec said:


> No confidence or do you just not read thread responses?


envisionelec,
Sorry i was just trying to help the guy. like i said i'm sorry.


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## envisionelec (Dec 14, 2005)

ace956 said:


> envisionelec,
> Sorry i was just trying to help the guy. like i said i'm sorry.


Sorry? Why? I just wanted to know if you had seen the responses.

Please don't feel bad - we're all just trying to help. No offense _ever_ intended. Geez, now _I _feel terrible. 

I plan to take photos / video of the repair to help others in the future.


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## ace956 (Aug 28, 2009)

envisionelec said:


> Sorry? Why? I just wanted to know if you had seen the responses.
> 
> Please don't feel bad - we're all just trying to help. No offense _ever_ intended. Geez, now _I _feel terrible.
> 
> I plan to take photos / video of the repair to help others in the future.


envisionelec,
I realy wasn't trying to make you feel bad. I read through all the messages again and I didn't understand what you were talking about, anyway I'm sorry. If youre going to repair it for him then I guess you solved his problem, great.

thanks Wade


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## envisionelec (Dec 14, 2005)

Got the amp on the bench this evening. Unfortunately, I didn't have a lot of time to look at it tonight.

Found this:

It's hard to see, but that's a 4R7 resistor burnt to a crisp. It's in the output zobel which points me to a pretty severe oscillation. I'll have more time later to look into the exact cause. In the meantime, I have to order a few parts. I'm keeping Hoot in the loop via PM. You guys will have to get the synopsis.


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## Hoot (Jan 18, 2008)

Aaron, thanks for doing this; helping me, and helping the forum.

~Hoot


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## envisionelec (Dec 14, 2005)

Hoot said:


> Aaron, thanks for doing this; helping me, and helping the forum.
> 
> ~Hoot


I've been asleep at the wheel this week. 



Anyway, the problem came from weakened board-to-board interconnect jacks. They're not hard to find or install, but you have to take the entire amp apart to get to them. Audison used the bitchiest *****-clips on their transistors. In order to remove/reinstall them without leaving a scratch, I basically destroyed the tendons in my right thumb. Yay. 

Let me heal for a couple days and I'll box 'er up and send it back. And it won't whine about it anymore.


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## Hoot (Jan 18, 2008)

Aaron,first of all...thanks!!! Second, shoot me an invoice via paypal and I'll pay asap. And, third, you can whine all you want as long as my amp no longer does!!! 

Thks, again!!!


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## Hoot (Jan 18, 2008)

By the way, Wade, thank you for going out of your way to help me, as well. This message board is full of good folk, and you are among them; again, thanks, Wade.


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## ace956 (Aug 28, 2009)

Hoot said:


> Love this amp - everything about it except for the cycling wine.
> 
> Here is the deal: Amp has some sort of internal output problem related to RCAs. Why do we know this? Isolated from the install on the test bench, with speaker wired connected, there is still a whining problem. In the install, we could sometimes get the amp to stop whining with a movement of the RCA wires, but right now it is whining all the time.
> 
> ...


HEY HOOT,
Did you ever get your noise problem taken care of? i hope all is going well. If you still need help contact me.

thanks, wade: ace956


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## envisionelec (Dec 14, 2005)

ace956 said:


> HEY HOOT,
> Did you ever get your noise problem taken care of? i hope all is going well. If you still need help contact me.
> 
> thanks, wade: ace956


I repaired the amplifier. It was a damaged DUBOX connector between the crossover and main PCB. I don't think he's had the chance to test it (but I did).


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## Hoot (Jan 18, 2008)

I've been nursing a cold and then our 70-degree sunny weather turned to snow in the last two days; a break with some sun today and a balmy 45 means I get out there today and get it installed, as our garage is full of boxes at the moment. I will post an update when I get things set - thanks, all, and thanks Aaron!


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## Hoot (Jan 18, 2008)

Well, I'd labeled all the speaker wire, RCAs, etc. so I don't think that's an issue in terms of things being reconnected properly, but sadly the problem persists. To Aaron's credit, I think it is better. The cycling pitch isn't as pronounced, and it sometimes seems to actually go away, but there is still noise pretty much on par, db-wise, with what I had. I think it is running through the entire system now, and seems even affected by buttons pushed on the H/U (e.g., pause button). I am right now at a loss.

I will dinker tomorrow as temps are supposed to climb back near 70 here in the Denver area, and I have the day off; otherwise, perhaps someone out there knows of really credible help here in northern Colorado.

Aaron, thanks, again, for all your efforts, and who knows this bugaboo might just get sorted out tomorrow with s'more tinkering, but my faith in such luck is waning....


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## Hoot (Jan 18, 2008)

The problem persists; its seems LESS audible, but still a problem. I am beginning to wonder if this was one of the original LRX5.1ks, as was mentioned the first lot or two had such a problem - I bought this amp second-hand from a guy on this board prolly 4 years or so ago, and there have been problems from the get-go.

Maybe you wanna take a crack at it Ace, or... does anyone know of a really reputatable shop in the Denver area that could give my whole electrical system a look over? 

Aaron, again, thanks, but she's still not where she needs to be, or at least my system isn't....


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## Hoot (Jan 18, 2008)

Actually, I don't think that, at this point, it is LESS audible than before. Any further ideas or suggestions are, in advance, graciously accepted.


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## envisionelec (Dec 14, 2005)

Hoot said:


> Actually, I don't think that, at this point, it is LESS audible than before. Any further ideas or suggestions are, in advance, graciously accepted.


Hmm, I don't recall getting an email from you regarding this. 

I strapped on a pair of headphones and listened. No noise. I really don't know what to tell you. There was an non-obvious problem with the PCB interconnect which took out a resistor in the output zobel. Indicative of upstream oscillation. 

The subwoofer channel is noisy - just a Class D-type amp with pretty significant stray radiation - but it doesn't whine. Its noise is broadband, so it's just "hissy". I wouldn't be surprised if it's causing your issues due to a faulty component (cracked capacitor or such). This would be very difficult to find, since the amplifier cannot be troubleshot without putting it all back together or building a specific jig.

Good luck to anyone else that attempts this repair. You're gonna need it. 

When you said that the H/U seems to affect it - I'm questioning what's going on outside the amp. Normally, external signal problems are attenuated at the amplifier's input using an RF stopper circuit. But, if the problem is riding on the signal ground, there is nothing stopping it from entering the amplifier. This would also explain why the zobel resistor was open. You really need to find another Audison to compare. Many amplifiers don't have the extensive input circuitry that this one does and will hide peculiar problems such as this.

I can refund the $$$.


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## Hoot (Jan 18, 2008)

Aaron, I don't fault you at all - seems like a bugaboo of a problem. I greatly appreciate your time and generosity - you certainly put in far more time and effort than the pennies you asked from me. Oh gosh nooooo, I would never ask you to refund the money. 

What I need to do is find a shop local and have it tested, yet again. Last summer the test preformed was on a bench and we simply hooked up speaker wire to speakers and listened - heard the same oscillating whine. 

Maybe I've got something reconnected wrong. I get a small thump when I turn off the deck now, and don't recall that. Again, we replaced all the RCA once already. The sound problem is constant and has nothing to do with the engine being on or off, and not an alternator issue, but maybe the problem is the sum of both a minor amp issue and something within the wiring of my system itself???


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