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Right Channel Cuts Out intermittently - help!

Hi all,
The right channel in my system cuts out intermittently, no matter what source I’m using. I’ll be listening to whatever, then suddenly I hear a static windy sound from the right channel, and then it cuts out. Then, it comes back, but not for long.
I hooked up a different speaker to that channel and the problem persisted. So, it’s not the speaker. And, as I already stated, it’s not the source components either.
I can’t afford expensive cables - I’m using heavy gauge speaker wire. There are no faults that I can detect in the wire.
Currently, I’m using a HK 4390 Receiver as a preamp/control unit, with a parasound a21 amp. I switched the ends of pre out cable, but the problem remained in the right channel. I also swapped it out with a new cable, which made no difference. The a21 is only a year old, and it is my understanding their build quality is superlative. This problem only started a couple days ago, and I’ve owned the a21 for about a month. It seems unlikely that it is the culprit.
I’m thinking it may be the pre out on the HK.
However, here’s the strangest bit: I disconnected the pre out cable from only the right channel on the a21. With no input from the HK, the static returned again in the right speaker for a brief moment. When I reconnected it, nothing changed. The channel still gets bouts of static, then cuts out.
This is driving me nuts. Could be a power cord or grounding issue? Any help would be greatly appreciated.

audiocronic
jea48
2,944 posts
 
I switched the RCA cables at the input jacks, and tried a new cable. Still, only the right channel cuts out.  
As in the input jacks on the parasound a21 amp?

That indicates a problem with the amp's right channel. You might want to make sure you have the IC RCA plugs plugged into the jacks all the way. You might also try physically lightly moving the RCA plug/jack back and forth and up and down and check it that affects the sound problem. It could possibly be a bad solder connection inside the amp.  

But, something is definitely wrong with the HK receiver. I disconnected the a21 completely, and hooked the speakers back up to my receiver. No sound at all. Just muffled noises coming from the sub.  
What process, procedure, is required to be followed for the preamp section of the HK to be reconnected to the power amp section of the receiver?

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audiocronic OP
3 posts
 
Yes, I switched the IC RCA input jacks on the a21, and the right channel continued to go out.  

As to your other question, as far as I'm aware, there shouldn't be any special procedure to use the HK by itself other than disconnecting the external amp (the a21) and reconnecting the speakers.  I looked in the manual, but I didn't find anything further than "how to connect an external amp". 

If the HK is acting up, there may not be an issue with the a21 (I hope).  Perhaps I'll try running an RCA cable directly to the a21 from my oppo 205.  If the right channel acts up then, that would definitely indicate a problem with the a21 (perhaps a bad solder as you said).  


jea48
2,944 posts
 

If the HK is acting up, there may not be an issue with the a21 (I hope).
When you swapped the left and right IC RCA plugs at the a21 the sound problem should have moved to the left ch/speaker of the amp. You said it remained on the right ch/speaker.

Perhaps I’ll try running an RCA cable directly to the a21 from my oppo 205.
Good idea. That eliminates the HK from the equation.

As to your other question, as far as I’m aware, there shouldn’t be any special procedure to use the HK by itself other than disconnecting the external amp (the a21) and reconnecting the speakers.
Has to be some kind of method.

Try connecting an IC from the PRE OUT jacks on the HK to the MAIN IN jacks on the HK.


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audiocronic OP
3 posts
 
Thanks! Running an RCA from the pre out to main in on the HK has it functioning again. With the speakers hooked up to the HK, the system works again (though, it certainly lacks the richness the a21 provided). Sometimes this stuff is still mysterious to me; before I got the external amp, I didn't have to connect anything to the pre out.  

Unfortunately, connecting the oppo directly to the a21 has proven that it is indeed malfunctioning.  The right channel continues to cut out.  I guess I'll have to ship it to Parasound for repair :/ 

Thanks for your help.
jea48
2,944 posts
 
Sometimes this stuff is still mysterious to me; before I got the external amp, I didn’t have to connect anything to the pre out.



From the owners manual:
Main-Amp Inputs and Preamp Outputs: These jacks are normally connected directly to each other with an included jumper. Some devices, such as equalizers and some loudspeaker systems, require connection between the Preamp Outputs and Main-Amp Inputs, in which case the jumpers should be removed and stored in a safe place for future use. You may also remove the jumpers if you wish to connect the Preamp Outputs to an external amplifier, or if you wish to connect another device’s line-level output directly to the HK 3490’s power amplifier for a special application.
http://static.highspeedbackbone.net/pdf/Harman%20Kardon%20HK3490%20Stereo%20Receiver%20Manual.pdf


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