Help with my MXR-130 Receiver

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dennismiller55
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Help with my MXR-130 Receiver

Post by dennismiller55 » Sun Jun 12, 2011 4:19 am

I know I have come to the right place. I seek Carver Guru Wisdom.

I have an annoying problem with my MXR-130 Receiver. Occasionally, one of the audio channels will fade to a low volume or just to nothing. Both channels do it randomly. On occasion, both channels will do it at the same time. When it first happened, turning the volume and or balance knob seemed to bring them back. Sometimes you would have to be aggressive in operating the knobs. I took the cover off to access these pots. I sprayed a lot of contact cleaner in the little holes on the pots and operated them while spraying. This seemed to work for a while. But it still does it. Now operating the knobs sometimes works and sometimes not. Turning the unit off and back on does seems to work. I cannot pin point a solution that works consistently. Kind of hit or miss.

So this is what I am thinking now. Could it be the output relays? Or do I have dead spots on the balance or volume knob which would require replacements?

Any help or advice is appreciated and welcome.

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helicopterpilotdoug
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Re: Help with my MXR-130 Receiver

Post by helicopterpilotdoug » Sun Jun 12, 2011 5:19 am

Hello, and Welcome to the forum! Sorry, I'm not one of the Guru's here, but I'm sure someone will be able to help you soon.
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dennismiller55
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Re: Help with my MXR-130 Receiver

Post by dennismiller55 » Sat Jun 25, 2011 11:24 am

dennismiller55 wrote:I know I have come to the right place. I seek Carver Guru Wisdom.
Helpful responses to my question are welcome from anyone not just a "Guru".

It is getting worse. I read somewhere (eBay I think), that if this problem presents itself in the speaker but not in the headphones, then it is the output relays. The problem is the headphone volume is so much less than the speakers. The speaker output drowns out any audio in my headphone. If I turn off the speakers and listen just in the headphone this problem does not seem to exist. I will continue this test for a while.

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kingman
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Re: Help with my MXR-130 Receiver

Post by kingman » Sat Jun 25, 2011 12:43 pm

Dennis...I have no idea...I would say spray it down inside with de-oxit making sure you get all the pots. If that doesn''t help it's time to think repair work. Are you equipped to troubleshoot this project? If not...several can help.
In reality, it only matters what it sounds like to YOU!!!

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jjptkd
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Re: Help with my MXR-130 Receiver

Post by jjptkd » Sat Jun 25, 2011 12:44 pm

Welcome! Old unit, probably needs servicing. Send it to Bob Carver's Audio Repair Center for refurbishing and have him sign it for you while its there. Good luck!
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dennismiller55
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Re: Help with my MXR-130 Receiver

Post by dennismiller55 » Sun Jul 03, 2011 10:20 am

Good News! I have fixed my own problem. It was both the left and right channel output relays. I thought I remembered reading about this problem somewhere. As it turns out there is a Service Bulletin that addresses this very problem. Also there is someone selling replacement relays on the big auction site. Delivery was quick. It was an easy solder job. Not only is the intermittent problem gone, the audio is clear. I don’t have the best ears anymore so I guess I did not realize how much distortion was also present.

Now I am happy.
Last edited by dennismiller55 on Sun Jul 03, 2011 3:31 pm, edited 1 time in total.

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engtaz
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Re: Help with my MXR-130 Receiver

Post by engtaz » Sun Jul 03, 2011 10:33 am

Congrats on the fix.
engtaz


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kingman
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Re: Help with my MXR-130 Receiver

Post by kingman » Sun Jul 03, 2011 1:53 pm

That's great!!! Enjoy the music!!! =D>
In reality, it only matters what it sounds like to YOU!!!

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dennismiller55
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Re: Help with my MXR-130 Receiver

Post by dennismiller55 » Tue Sep 27, 2011 5:39 pm

Now I have a differnt problem. Well, I guess it has always been there. I just could not hear it at low volumes which is my norm. There is a constant hum, both channels.

Could this be the power supply capacitors. I am sure replacing all the electrolytic would remove the hum and improve the overall audio quality.

What do you think?

Dennis

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kingman
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Re: Help with my MXR-130 Receiver

Post by kingman » Tue Sep 27, 2011 6:09 pm

Check the ground loop. If you have it plugged into a power strip bypass and plug into the wall. Anything else plugged into the wall outlet besides it? :-s I am assuming 2 prong plug..... :-s
In reality, it only matters what it sounds like to YOU!!!

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