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An unusual problem that merits an unusual solution

Hello all,

I recently aquired a Marantz AV-550 preamp and 5 MA-500 monoblocks, and now I'm running into an odd problem. Any time the preamp gains and loses signal, there's a loud, "POP!" in the right surround channel. This means that any time you do *anything* to the DVD player - pause, cue, review, chapter next, menu - the right surround pops loudly.

Because I'm not sure this is a repairable problem, I'd like to just cut down the volume of said "POP". My idea was this:

The volume of the preamp does not affect the volume of the pop. Therefore, if I could wire an in-line resistor of some sort between the preamp and the amp, it would cut down the volume of the channel, and I could just turn up the volume of that surround channel in the preamp to compensate.

My question: does anyone make an RCA coupler which has a resistor or potentiometer built into it, or will I need to build something?

If I have to build something, what would be an appropriate level of resistance to use, or should I use a pot?

Thanks in advance for lending your expertise,

Scott
hudsonhawk

Showing 3 responses by hudsonhawk

hudsonhawk OP
137 posts
 
I was poking around online and found this:

http://www.smarthomeusa.com/ShopByManufacturer/Channel-Vision/Item/3107/

I really don't understand electricity, so I was wondering - is this an appropriate solution? How much volume difference will 15k ohms make on line-level?

Thanks in advance!
hudsonhawk OP
137 posts
 
Interesting, makes me wonder if it's something with that (now seemingly ancient) Yamaha AC-3 decoder chip in the AV-550's. Mine may be popping in the LFE channel as well - but I have no sub to hear it with.

Looks like I may have found a solution though - someone emailed me and pointed out the Rothwell in-line RCA attenuators (man I wish I'd known about those when I had my Jolida Tube Amp - it's gain was *way* too high!)

I'm also going to order the Channel Vision 15k Ohm inline resistors as a backup (and for comparison).
hudsonhawk OP
137 posts
 
Just for reference to anyone else who has this problem in the future, I was able to get -6dB attenuators from Parts Express that did the trick nicely.

The "pop" is still there - but it's so much quieter you can barely hear it anymore.

Oddly enough, there's a new sound that's appeared since adding the attenuator - any time the Marantz receives an IR burst - even if the IR is intended for another component - I get a wierd beeping from the same troublesome right surround channel. It sounds sort of like a modem or a fax machine, and is only a second or two long.

Clearly the preamp has issues, but it should get me by until I can afford an Acurus Act-3 or an Outlaw 950. Considering I paid 70 bucks for it on Ebay, I don't really have any right to complain!

Thanks for the suggestion, Sean; no luck however. Our power does seem very dirty and unstable - it's an old house with old wiring in a dense urban neighborhood, and I'm sure that doesn't help. If I could afford a nice power conditioner, I'd get one, but AC stuff is just too expensive. Especially having the quintet of MA-500's - that's 5 outlets right there!

Thanks to everyone for their help in this thread, and over email.
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