Marantz amp problem, sudden "gargly" sound

[Scott Dolan]

Is it? That's awful. 

I had a Pioneer VSX for 12 years, and a Harmon Kardon AVR for 14 years. Both in heavy rotation with no issues. 

I wonder if it has to do with how much more computerized everything is now? 

All is well with my current amp and preamp of three years. I was hoping they'd be my last. Perhaps I better adjust my expectations...

[sidewinder]

With the electrolytics it is just basic chemistry - with time the electrolytes degrade and don't hold the charge as well. I had to have re-done my old power amp after 10 years and that was already its 2nd re-cap. 

[Larry Kart]

3 hours ago, riddlemay said:

Coming out of lurkdom because "gargly" is a pretty good descriptor of the high-frequency musical sounds I'm hearing with the hearing aids I've been trying out (and am finding unacceptable as a result). So Larry, I have the same question re whether your hearing aids are in or out while listening through headphones. If they are out, that keeps open the possibility that the hearing aids are the culprit.

They're in when I listen on headphones.

[Scott Dolan]

2 hours ago, sidewinder said:

With the electrolytics it is just basic chemistry - with time the electrolytes degrade and don't hold the charge as well. I had to have re-done my old power amp after 10 years and that was already its 2nd re-cap. 

Ah, that makes perfect sense. Guess I just got lucky previously. Kind of similar to car batteries, I suppose. Most only last about five years, yet my last one lasted for seven. And it was actually OEM, surprisingly. 

*sigh*

Well, at least I have some time to save up my money...

[Kevin Bresnahan]

Marantz's Reference Series is not likely to use cheapie Aluminum electrolytic capacitors. They brag about this amplifiers design and proprietary components in their literature. They even highlight their capacitors as being "stress free". See http://www.vintageshifi.com/repertoire-pdf/pdf/telecharge.php?pdf=Marantz-SA-15-S-1-Brochure.pdf

"Custom-made components inside the SA-15S1 include new stress-free electrolyte capacitors and the Shottky diodes, which also feature in the rectifier circuitry. The audio circuitry uses high-grade electrolytic and film capacitors, to ensure the excellence you demand from Marantz products."

Edited September 18, 2017 by Kevin Bresnahan

[Scott Dolan]

Kevin, with your background as an EE, do you agree with sidewinder's assertion of ten years being the median cutoff for electrolytic capacitors? 

I have no reason to doubt it, but wonder what your opinion is. 

And in fairness, which I'm thinking you'll agree, literature surrounding electronics, especially audio equipment, can sometimes be a little...um..."enhanced for effect". 

[Niko]

[after a more than a decade on the .org and a day of trying to make sense of some fancy ee papers:] sidewinder also has a reasonably fancy ee background

[Larry Kart]

Took the amp in to Music Direct, where I bought it back in 2009. When they hooked it up, things sounded perfectly OK. That kind of leaves the BW 800 speakers (or their tweeters) as the culprit, but, yet again, how likely is that two speakers would develop this problem at the same time. A blast of sound through the speakers that would  have damaged the tweeters? Possible, but I would have heard that event, and I heard no such thing. Music Direct said go back home, hook up the amp again and pray. Or buy some other speakers on spec, take them home, and return them if the problem remains.

[Larry Kart]

Spoke to Audio Consultants in Evanston, Il., which sold me the used BW 805 (not B&W 800) speakers (my error) back in 2005. They listened to my story, said that it sounds like some dire sonic event blew the tweeters. (Well, I did listen to three CDs worth of Terry Gibbs the other day! ) In any case, they'll test out the speakers, and if the tweeters are cooked, they said they can be replaced.

[paul secor]

I hope your problem is resolved soon, and that you're back to listening soon.

[Scott Dolan]

5 hours ago, Niko said:

[after a more than a decade on the .org and a day of trying to make sense of some fancy ee papers:] sidewinder also has a reasonably fancy ee background

Ah, I didn't realize that. 

I certainly meant no offense. 

[sidewinder]

9 hours ago, Larry Kart said:

Spoke to Audio Consultants in Evanston, Il., which sold me the used BW 805 (not B&W 800) speakers (my error) back in 2005. They listened to my story, said that it sounds like some dire sonic event blew the tweeters. (Well, I did listen to three CDs worth of Terry Gibbs the other day! ) In any case, they'll test out the speakers, and if the tweeters are cooked, they said they can be replaced.

Glad to hear that diagnostic progress is being made. A capacitor issue would have been more gradual, so this sounds more likely.

6 hours ago, Scott Dolan said:

Ah, I didn't realize that. 

I certainly meant no offense. 

 None taken.

Edited September 19, 2017 by sidewinder

[Kevin Bresnahan]

15 hours ago, Larry Kart said:

Spoke to Audio Consultants in Evanston, Il., which sold me the used BW 805 (not B&W 800) speakers (my error) back in 2005. They listened to my story, said that it sounds like some dire sonic event blew the tweeters. (Well, I did listen to three CDs worth of Terry Gibbs the other day! ) In any case, they'll test out the speakers, and if the tweeters are cooked, they said they can be replaced.

My Marantz PM-7005 is also hooked up to B&W 805s speakers too. We have a similar set up.

I have difficulty believing that both tweeters failed simultaneously. FWIW, I have heard many blown tweeters and "gurgly" is not the sound I would ever use to describe what I heard. It is usually a high-pitched, almost painful buzz. The sound will break up and not be constant. I don't think it's your tweeters.

BTW, if you do get the tweeters replaced, make sure to get the equivalent tweeter. B&W revised the N805 to the N805S right around the time you bought them. I think the tweeter is a little different on each of the models. I know the crossover is different. Maybe you could splurge and get a Diamond tweeter. ha ha ha... I don't think you could do that as the crossover probably isn't set up for that load. But it's worth thinking about.

[Larry Kart]

1 hour ago, Kevin Bresnahan said:

My Marantz PM-7005 is also hooked up to B&W 805s speakers too. We have a similar set up.

I have difficulty believing that both tweeters failed simultaneously. FWIW, I have heard many blown tweeters and "gurgly" is not the sound I would ever use to describe what I heard. It is usually a high-pitched, almost painful buzz. The sound will break up and not be constant. I don't think it's your tweeters.

BTW, if you do get the tweeters replaced, make sure to get the equivalent tweeter. B&W revised the N805 to the N805S right around the time you bought them. I think the tweeter is a little different on each of the models. I know the crossover is different. Maybe you could splurge and get a Diamond tweeter. ha ha ha... I don't think you could do that as the crossover probably isn't set up for that load. But it's worth thinking about.

The mystery deepens. I would say that both tweeters could fail simultaneously if they were subjected to the same electronic/sonic distress, but I don't know what that could have been other than a steady diet of Terry Gibbs (I'm kidding, but that's the only "event" that fits.) OTOH, could there have been such an event -- a power surge, say -- when I wasn't listening?

[Kevin Bresnahan]

18 hours ago, Scott Dolan said:

Kevin, with your background as an EE, do you agree with sidewinder's assertion of ten years being the median cutoff for electrolytic capacitors? 

I have no reason to doubt it, but wonder what your opinion is. 

And in fairness, which I'm thinking you'll agree, literature surrounding electronics, especially audio equipment, can sometimes be a little...um..."enhanced for effect". 

Nothing fancy about my EE degree, it's just a regular old EE degree. However, my career has long swung to the RF side of EE (GHz stuff) so circuit design and analysis is a distant memory. I can bias up and test just about any RF circuit you put in front of me. But don't ask me to debug your amplifier's schematic. I'm not the right guy for that anymore. Ancient history for me.

I think sidewinder is referring to caps from the great capacitor scandal from a while back. The story goes that the formula got messed up for the gunk that goes into the cheaper Aluminum caps. He may be right that this is still a problem for all amps. I just have trouble believing that Marantz would have used these cheap caps, especially in their Reference Series. Maybe they did, but if they truly used them in a "low stress" circuit (their words), they should be OK, as the ratings for most caps are specified under full load i.e. stressed to the max.

[jazzbo]

"Gurgling" sounds more like midrange drivers than tweeters. 

This is a puzzling problem, I hope you can get to the bottom of it and soon. 

[Kevin Bresnahan]

1 hour ago, jazzbo said:

"Gurgling" sounds more like midrange drivers than tweeters. 

This is a puzzling problem, I hope you can get to the bottom of it and soon. 

The B&W N805 is a two-way design. No midrange speaker. However, I agree that "gurgling" is typically not a sound reproduced by a tweeter, so i would suspect the low frequency driver over the tweeter. Of course, there could be a problem with the crossovers, but again, having both fail at the same time seems very unlikely.

[Larry Kart]

I say "gurgling" because that was my initial approximation -- it's a watery, tremolo-like breakup (like a scummy sheen) on any and all upper-register sounds, especially if they're percussive. A work by Liszt or Bartok, for example. If the source is piano music, where these effects are particularly evident, percussive low-register notes and chords also "bang" ("clip"?) and break up, while on headphones all sounds normal. I should re-emphasize that when I took the amp back to Music Direct yesterday and they tested it while I listened, everything sounded normal. Brought the unit home, hooked it up again, and the problem was as before.

[Kevin Bresnahan]

1 hour ago, Larry Kart said:

I say "gurgling" because that was my initial approximation -- it's a watery, tremolo-like breakup on any and all upper-register sounds, especially if they're at all percussive. A work by Liszt or Bartok, for example. If the source is piano music, where these effects are particularly evident, percussive low-register notes and chords also "bang" ("clip"?) and break up, while on headphones all sounds normal.

"Break up" sounds like it could be a tweeter. But again, it's usually a higher-frequency buzz like a loud mosquito.

Did you ever get a chance to try different speaker wires?

[Larry Kart]

1 hour ago, Kevin Bresnahan said:

"Break up" sounds like it could be a tweeter. But again, it's usually a higher-frequency buzz like a loud mosquito.

Did you ever get a chance to try different speaker wires?

Yes, Music Direct sold me a new set of speaker cables, Audioquest Rocket 33s, on the chance that they would help. If not, a set of new cables after nine years would still be a good investment, I thought, no matter how all this is resolved.

[Scott Dolan]

In fairness, cables don't really degrade over time. If you get the same results, and I'm betting that you do, you should really get your money back, IMO. 

And I'm with Lon. This is the most bizarre problem I've ever heard of. 

[Kevin Bresnahan]

1 hour ago, Larry Kart said:

Yes, Music Direct sold me a new set of speaker cables, Audioquest Rocket 33s, on the chance that they would help. If not, a set of new cables after nine years would still be a good investment, I thought, no matter how all this is resolved.

The speaker wires are worth a shot (you could've used some cheap lamp cord as a quick check). I'll be pleasantly surprised if that's it.

I still agree with most of the other posters that both speakers being affected sounds like an amp/preamp problem. Crappy luck if you just happened to blow both speakers together. I have heard stories of it happening from a lightning strike. I've blown a few tweeters in my day but never both at once.

Edited September 19, 2017 by Kevin Bresnahan

[sidewinder]

19 hours ago, Kevin Bresnahan said:

Nothing fancy about my EE degree, it's just a regular old EE degree. However, my career has long swung to the RF side of EE (GHz stuff) so circuit design and analysis is a distant memory. I can bias up and test just about any RF circuit you put in front of me. But don't ask me to debug your amplifier's schematic. I'm not the right guy for that anymore. Ancient history for me.

I think sidewinder is referring to caps from the great capacitor scandal from a while back. The story goes that the formula got messed up for the gunk that goes into the cheaper Aluminum caps. He may be right that this is still a problem for all amps. I just have trouble believing that Marantz would have used these cheap caps, especially in their Reference Series. Maybe they did, but if they truly used them in a "low stress" circuit (their words), they should be OK, as the ratings for most caps are specified under full load i.e. stressed to the max.

Must qualify my comments to say that this re-cap thing is certainly specific to large capacity reservoir capacitors on Naim power amps and power supplies. It is very noticeable when they do deteriorate. Certainly not a cheap type either, will apply to all reservoir caps I think.

Edited September 20, 2017 by sidewinder

[Scott Dolan]

5 hours ago, Kevin Bresnahan said:

 

I still agree with most of the other posters that both speakers being affected sounds like an amp/preamp problem. Crappy luck if you just happened to blow both speakers together. I have heard stories of it happening from a lightning strike. I've blown a few tweeters in my day but never both at once.

The problem being the only way to blow a tweeter is by overloading the voice coil, which would have to be done by cranking the tone control/EQ to limits it cannot handle. Is there any other way? Because Larry stated earlier he's only used factory settings. 

[Larry Kart]

Took the speakers in to Audio Consultants, and they/we heard the same thing I've been hearing at home. They found what we were hearing to be "strange" but will have their tech take a look and report back. So it's almost certainly/exclusively the speakers that are the problem. Also, almost without doubt, if there is a way to fix/repair the problem, that would be worthwhile. A new pair of B&W 805s now goes for $7,000!