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Discussion Starter #1
Ok guys, I'm getting frustrated here with YAMAHA products. I need your expert opinion and possible solutions to my problem. I need to know what is wrong.

I had initial system with a problem detailed here: http://www.hometheatershack.com/forums/home-theater-receivers-processors-amps/83546-rx-a2030-keeps-shutting-down.html

So I've decided to upgrade. Here is the update:

I returned the RX-A2030 and I have upgraded to separates: CX-A5000 + MX-A5000

The amp keeps on shutting down again at around 0 dB volume level! but the Pre-amp stays on.

I need to know what is wrong! Is it the speakers?? Is it possible that the one of the fronts have a defect?

PLEASE HELP!
 

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The last time you posted you reported the shop you bought your gear from had decided the original AVR was defective and was going to install and test a new AVR.
Did that happen?

In my opinion you need in home technical assistance.
 

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Well considering your new setup is also shutting down that rules out the amp or the processor. I would try a new set of speaker wires and also triple check the connections at the amp and the speakers for any loose strands of wire. Are any of the speaker cables run in the wall?
 

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I agree it sounds like a short... either in a wire or a speaker driver...grab an OHM meter and start testing each speaker wire at the amp location.
 

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Discussion Starter #5
The last time you posted you reported the shop you bought your gear from had decided the original AVR was defective and was going to install and test a new AVR.
Did that happen?

In my opinion you need in home technical assistance.
That's correct. I asked for a technical assistance but I felt some kind of resistance. Anyways, I will try to find a solution instead of waiting
 

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Discussion Starter #6
Well considering your new setup is also shutting down that rules out the amp or the processor. I would try a new set of speaker wires and also triple check the connections at the amp and the speakers for any loose strands of wire. Are any of the speaker cables run in the wall?
I went and bought new cables and I bought this: http://www.vandenhul.com/products/cables/speaker-cables/twin-lead/cs-122-hybrid-halogen-free


To replace the monster cables... Same results....
 

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I went and bought new cables to replace the monster cables... Same results....
And no cables are in the walls? then it must be one of the speakers or your running it really loud.
 

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Yamaha products are well known to be conservative in terms of their protection circuits. It is not uncommon to see them shut down at 0dB, IME (which is a couple of years old in terms of doing lots of installations). If you are driving the input near 0dB it would not surprise me to see shutdown with some speakers that would give a resistance reading of 6 ohms. What speakers are these.
 

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Discussion Starter #12
What kind of speakers are you using (make and model)? Do you have the equipment set up in a cabinet with no ventilation (e.g. with a rear panel and glass front doors)? Or do you have equipment sitting directly on top of the amplifier? Or both?

Regards,
Wayne
Hi Wayne, I have YAMAHA Soavo-1, here is a link that shows more info about the speakers: http://usa.yamaha.com/products/audio-visual/speaker-systems/home-speaker-systems/soavo/soavo-1_birch__u/?mode=model

The pre and the amp are inside separate cabinets but with open front and rear. Clearance on the sides is about 5 inch and about 10 inches from the top.
 

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Okay then, doesn’t look like you have an installation issue. Since you had the same problem with two different amplifiers, the only other thing it can be is that the amps are rated for 8-ohms and your speakers are 6-ohms. Sell the MX and get an amp rated for 4-ohms and you should be fine then.

Regards,
Wayne

 

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I wouldn't rule out a speaker defect. When the problem first originated were the speakers new to your system? I had a similar problem with a set of speakers I bought used years ago, it turned out to be a wiring problem internally in one of the speakers. That amp probably isn't the best you could buy for that amount of money, but the preamp is as good as any. That said, the amp should still be able to drive your speakers to reference level without going into protection mode unless there is a short or reverse polarity somewhere.
 

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Okay then, doesn’t look like you have an installation issue. Since you had the same problem with two different amplifiers, the only other thing it can be is that the amps are rated for 8-ohms and your speakers are 6-ohms. Sell the MX and get an amp rated for 4-ohms and you should be fine then.

Regards,
Wayne
That amp can easily drive 4 ohm speakers. I believe there is an issue with an intermittent short on the speakers themselves.

Amplifier Section Channel 11
Rated Output Power (1kHz, 1ch driven) 230 W (6 ohm, 0.9% THD), 190 W (8 ohm, 0.9% THD)
Rated Output Power (1kHz, 2ch driven) 170 W (8 ohm, 0.9% THD)
Rated Output Power (20Hz-20kHz, 2ch driven) 170 W (6 ohm, 0.06% THD), 150 W (8 ohm, 0.06% THD)
Dynamic Power per Channel (8/6/4/2 ohms) 190 / 250 / 350 / 500 W
Audio Features Digital ToP-ART / High Current Amplification Three stage Darlington power stage
Current Feedback Amplifier Circuit Yes
Extensive Connection Analog Audio Input/Output XLR balanced: 11 / 0, RCA unbalanced: 11 / 0
Zone Control +12V Trigger Output Out: 1, Trigger in / Through: 1 / 1
General Auto Power Standby Yes
Power Consumption 650 W
Dimensions (W x H x D) 17-1/8” x 8-1/4” x 18-1/8”
Weight 56 lbs.l


From audioholics;

Power Measurements

The MX-A5000 was tested on a dedicated 120V / 20A line.

We tested power using three methods all of which were taken at < 0.1% THD + N:

Continuous Full Power Bandwidth (CFP-BW) from 20Hz to 20Khz into 8 and 4-ohm loads
1kHz Power Sweep vs. Distortion (1kHz PSweep)—popularized by the print magazines, this is an instantaneous power vs. distortion test at 1kHz. The problem with this test is it often masks slew-related and or frequency response problems some amplifiers exhibit at the frequency extremes, and thus inflates the measured power results. It does provide an instant gratification number for consumers to argue over on the forums, so we are now incorporating this test to please the masses.
Dynamic PWR - 1kHz CEA-2006 Burst Method testing. This is a dynamic power measurement adopted from the car industry similar to IHF method, only a bit more difficult for an amplifier and more representative of real musical content.

Keep in mind most review publications don't do continuous power measurements and they usually publish power measurements into clipping at 1% THD + N. Our measurements are very conservative since we use a dedicated 20A line with no Variac to regulate line voltage. We constantly monitor the line to ensure it never drops more than 2Vrms from nominal, which in our case was 120Vrms.

For more info on amplifier measurements, see: The All Channels Driven (ACD) Test

Yamaha MX-A5000 Power Bandwidth

Yamaha MX-A5000 Full Power Bandwidth Continuous Sweep (250wpc, 4 ohms)

The MX-A5000 easily exceeded its 150 watt/ch rating with two channels driven producing 177 watts/ch into 8 ohms and 250 watts/ch into 4 ohm loads at 0.1% THD + N.

MX-A5000 5CH Psweep

MX-A5000 PSweep-2CH

Yamaha MX-A5000 1kHz Power Sweep Test

Top Pic: 8 ohm load, 5CH; Bottom Pic: 4 ohm load, 2CH

The power sweep tests produced some interesting results with the MX-A5000. With 2 or 5 channels driven, the MX-A5000 did exceedingly well pumping out 177 watts (2CH, .1% THD + N) and 138 watts (5CH, .1% THD + N) respectively. However once 7 channels were tested, the MX-A5000 went into current protection mode delivering only 78 watts at .1% THD + N. This was a bit odd since 138 x 5 = 690 watts is greater than 78 x 7 = 546 watts. The MX-A5000 was clearly current limiting once it detected 7 channels driving at high power.

MX-A5000 Imp Low Psweep

Yamaha MX-A5000 1kHz Power Sweep Test – Low Impedance Mode

NEVER USE THIS SETTING!


http://usa.yamaha.com/products/audio-visual/aventage/mx-a5000_black_u/?mode=model
 

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Seems like I've heard of this when crossover components go bad. Do you have another pair to try out? I would guess your ohm test would reflect a bad component, but that's a guess. Electronics can do strange things under loads, or current. Have you tested each driver individually? MV at 0 is pretty loud, but I think you said it started shutting down at -11. Still pretty loud but surprising to see a failure at that level.
 

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How many speakers are you running?

Have you measured your power from the wall outlet ? What did you get?
( Power and neutral to ground numbers)

Do you notice things like lights dimming when you power on the amp?

Try playing the front two channels and add one speaker at a time till you get it to shut down then you might notice the last speaker caused the shut down.
When your done add all the speakers but leave that one out and see if it shuts down
This assumes it may be a speaker problem.

I'm leaning toward the Yamaha over protection kicking in but you need to rule these things out.

Try these things
 
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