Yamaha MX-A5200 cooling fan issue

[aislam]

Hello guys,

Recently I have bought a Yamaha MX-A5200 11 channel amp. This unit is now connected to a Marantz AV7706 11 channel pre-pro, and a pair of Buchardt S400 MKII (4 ohms load) speakers. Right now I am using this for two channel listening and the impedance switch is set to 4 ohms. The problem is both of it's fans at the bottom turn on briefly for 2 seconds when I push the power-on button, and then fans never turn back on again. The unit gets pretty hot (not warm, rather HOT) on the top, specially on the right and left top sides.

What could be the issue? My house does not have a ground connection (if it has anything to do with the fan). Any tips/advice from your end would be a tremendous help for me. Thanks a lot in advance.

 

[Pogre]

Well first you should flip that impedance switch to the 8 Ohm setting. The 4 Ohm setting limits how much power goes to your speakers.

Aside from that, what problem are you experiencing..? The fan coming on when it gets hot is what it's supposed to do.

 

[aislam]

Well first you should flip that impedance switch to the 8 Ohm setting. The 4 Ohm setting limits how much power goes to your speakers.

Aside from that, what problem are you experiencing..? The fan coming on when it gets hot is what it's supposed to do.

Thanks for your reply. My speaker is rated as 4 ohms, so still I have to turn the switch to 8 ohms?

I have waited several hours and the top gets quite hot too but no fans. It's like not warm, rather really hot. I can touch it but it is uncomfortably hot. Do you also own the same model?

 

[TLS Guy]

Hello guys,

Recently I have bought a Yamaha MX-A5200 11 channel amp. This unit is now connected to a Marantz AV7706 11 channel pre-pro, and a pair of Buchardt S400 MKII (4 ohms load) speakers. Right now I am using this for two channel listening and the impedance switch is set to 4 ohms. The problem is both of it's fans at the bottom turn on briefly for 2 seconds when I push the power-on button, and then fans never turn back on again. The unit gets pretty hot (not warm, rather HOT) on the top, specially on the right and left top sides.

What could be the issue? My house does not have a ground connection (if it has anything to do with the fan). Any tips/advice from your end would be a tremendous help for me. Thanks a lot in advance.

Your unit does not have a grounding pin. So your house should have a ground, but that is not your fan issue.

The fan will be on a thermostat. The user manual and specs are silent about the fan operation.

You will have to ask Yamaha what the optimal operating temp should be. These days the optimal operating temperature of solid state devices varies greatly.

So either your amp does not exceed safe operating temperature, or the thermostat is faulty. I can't tell you which, so ask Yamaha.

One further thought is you could buy one of those gun thermometers that accurately measure temperature at a distance. I have one in my electronics workshop. They are very useful.

I would say that if the temp of the case is 60 degrees C or lower, you are likely OK. If higher than that, there could well be a problem.

 

[lovinthehd]

You can always add external cooling fans as well, if a particular heat issue Yamaha doesn't have a solution for. Does your amp have sufficient ventilation?

 

[Pogre]

So either your amp does not exceed safe operating temperature, or the thermostat is faulty. I can't tell you which, so ask Yamaha.

Or it just doesn't kick on until it gets hot.

Thanks for your reply. My speaker is rated as 4 ohms, so still I have to turn the switch to 8 ohms?

That switch is there to meet regulations, but what it really does is limit the power going to your speakers. Here's a quick video where gene explains.

As far as your heat/fan issue goes, if it's really concerning you get a temperature reading to see how hot it's getting and run it by Yamaha. My guess is it just gets pretty warm before the fan kicks on and might be perfectly normal. My avr gets pretty warm too, even under normal operations.

 

[TLS Guy]

Regarding the four ohm switch, that amp does not have a four ohm rating. Using the four ohm switch will limit power. However if your speakers are truly four ohm, I would not use the amp hard.

I think those multichannel amps are a daft idea. When you get down to it they are run off one power supply and not very powerful

I recommend 19" rack class D 2 channel amps. Six in a 19" rack is the way to go.

I am noticing an uptick in requests from local friends for service of the stupid things. I went to see one, and it was so heavy I can't lift it! So Heaven knows how you would service it!

So they are another bunch of stupid contrivances well off my recommended list. Do two, or at most 3 channel. Best solution is pro amps though, and rack mount. That is a neat manageable solution.

 

[NMG]

How much ventilation do you have around the amp?

For what it’s worth, I have the same amp running my 7 channel B&W system and under normal conditions I’d say it gets slightly warm at the worst. Nothing even remotely close to hot and I’ve never heard the fans engage. My left and right speakers are 8 ohm nominal, but they do dip down to 4 ohm for much of the frequency range.

If the amp has lots of ventilation (mine is not in a cabinet, it’s sitting on a shelf open air) I’d be inclined to have your dealer take a look at it for possible defects. The fans kicking on at the start seem weird to me and of all the reviews I’ve read, running hot was never raised as an issue.

 

[PENG]

Hello guys,

Recently I have bought a Yamaha MX-A5200 11 channel amp. This unit is now connected to a Marantz AV7706 11 channel pre-pro, and a pair of Buchardt S400 MKII (4 ohms load) speakers. Right now I am using this for two channel listening and the impedance switch is set to 4 ohms. The problem is both of it's fans at the bottom turn on briefly for 2 seconds when I push the power-on button, and then fans never turn back on again. The unit gets pretty hot (not warm, rather HOT) on the top, specially on the right and left top sides.

What could be the issue? My house does not have a ground connection (if it has anything to do with the fan). Any tips/advice from your end would be a tremendous help for me. Thanks a lot in advance.

Before buying a power amp, one should first do the math or use an online calculator to figure out the best estimated power requirement.

It is a little late now but you should still do it as it will help determine the reason for your amp to get "hot" and/or come up with a plan to address the concern.

You can use the Crown audio one or the often suggested spl calculator.

Peak SPL Calculator

 

[aislam]

How much ventilation do you have around the amp?

For what it’s worth, I have the same amp running my 7 channel B&W system and under normal conditions I’d say it gets slightly warm at the worst. Nothing even remotely close to hot and I’ve never heard the fans engage. My left and right speakers are 8 ohm nominal, but they do dip down to 4 ohm for much of the frequency range.

If the amp has lots of ventilation (mine is not in a cabinet, it’s sitting on a shelf open air) I’d be inclined to have your dealer take a look at it for possible defects. The fans kicking on at the start seem weird to me and of all the reviews I’ve read, running hot was never raised as an issue.

I am also using it on open shelf, getting input from Marantz AV7706 as preamp. I am not sure why it is running quite hot. I wrote to Yamaha and the dealer, both of them said it is not abnormal to run hot, and the fan will not turn on until the heat sink reaches certain temperature. Their message is to not to worry. But still... as you said your's is running warm (not hot), now I am guessing that it might be the issue with my 4 ohms rated speaker Buchardt. Still puzzled though.

 

[AcuDefTechGuy]

It should definitely not be hot, especially in COLD weather like now.

When it's 32F degrees outside, by MX-A5000 feels COLD after hours of use because my Equipment Closet is like 60F degrees.

 

[Pogre]

It could be your speakers' impedance are dipping low enough to warm things up a bit. It'd be useful if you could get a temp reading somehow. You don't happen to have one of those infrared thermometers do you? Borrow one from a friend? If you really wanna know I don't think they're prohibitively expensive.

 

[aislam]

It could be your speakers' impedance are dipping low enough to warm things up a bit. It'd be useful if you could get a temp reading somehow. You don't happen to have one of those infrared thermometers do you? Borrow one from a friend? If you really wanna know I don't think they're prohibitively expensive.

I have one inside the closet somewhere, have to find and will post the temperature. Yeah, I think it's the speaker causing such havoc.

 

[PENG]

It could be your speakers' impedance are dipping low enough to warm things up a bit. It'd be useful if you could get a temp reading somehow. You don't happen to have one of those infrared thermometers do you? Borrow one from a friend? If you really wanna know I don't think they're prohibitively expensive.

Aside from being 4 ohms nominal, likely have dips to 3 ohms or less, they might also have some nasty phase angles that coincide with the impedance dips. Phase angles don't result in higher current, but it will increase the heat dissipation in the amp.

We need to see the impedance and phase angle vs frequency graph. I searched and could not find any, unfortunately.

 

[PENG]

Hello guys,

Recently I have bought a Yamaha MX-A5200 11 channel amp. This unit is now connected to a Marantz AV7706 11 channel pre-pro, and a pair of Buchardt S400 MKII (4 ohms load) speakers. Right now I am using this for two channel listening and the impedance switch is set to 4 ohms. The problem is both of it's fans at the bottom turn on briefly for 2 seconds when I push the power-on button, and then fans never turn back on again. The unit gets pretty hot (not warm, rather HOT) on the top, specially on the right and left top sides.

What could be the issue? My house does not have a ground connection (if it has anything to do with the fan). Any tips/advice from your end would be a tremendous help for me. Thanks a lot in advance.

The Buchardt S400 MKII may be the culprit that sucks the MX-A5200 dry, but how about the other 9 speakers? Are they 4 or 8 ohms with lower than average sensitivity, and how far are those from you main seat?

If the A5200 is running hot because of the Buchardt, and assuming you only need 500 W 4 ohms, you can quickly solve the problem by spending less than $1,000 on a 2 channel Hypex 502MP. Buchardt apparently sells Hypex NC amps so I guess they know.. Keep in mind, as you know now by using the 4 ohm impedance setting you are limiting the potential of your very nice S400 MKII speakers and even then, apparently your amp runs hot, so it is not just an overheating issue, but potentially a sound quality issue as well if the speakers are not given the current it needs at all time under all conditions.

 

[aislam]

Aside from being 4 ohms nominal, likely have dips to 3 ohms or less, they might also have some nasty phase angles that coincide with the impedance dips. Phase angles don't result in higher current, but it will increase the heat dissipation in the amp.

We need to see the impedance and phase angle vs frequency graph. I searched and could not find any, unfortunately.

By the way, this unit is an UK model and running on 220v AC power (not 230v or 120v). Do you think this could add to the problem? My UK dealer said, it usually runs hot, so it's not abnormal.

 

[PENG]

By the way, this unit is an UK model and running on 220v AC power (not 230v or 120v). Do you think this could add to the problem? My UK dealer said, it usually runs hot, so it's not abnormal.

Okay but as TLSGuy suggested, you should still measure the temperature, "hot" and "usually runs hot" could mean different things to different people so it is better to rely on facts and data. Again even if it isn't really too hot, using the 4 ohm setting will limit the maximum current that your speakers may need depending on the media contents, your seating distance and listening habits.

 

[NMG]

I believe you’re only running 2 speakers also are you not?

I definitely agree about not using the 4 ohm switch. Do the fans always run when you first turn it on? That just seems weird to me considering they should only run if an overheat situation is detected. Not sure why they’d turn on when it’s first powered up.

I can put my hand on the top of mine after it’s been in use for hours and it feels luke warm. If I’m really pushing it, it might get to warm. Never even close to the realm of “this feels uncomfortable on my hand” and no noticeable heat whatsoever on the sides. They stay cold.

Do you happen to have access to some other speakers that you could try just to see how it responds to different loads? That might help you see if it responds differently.

 

[TLS Guy]

I have one inside the closet somewhere, have to find and will post the temperature. Yeah, I think it's the speaker causing such havoc.

I think the answer lies in your speakers. They have adverse impedance and phase angle curves. Not the worst, but on the difficult end. I could well understand why they would make an amp cook.

Those are Erin's measurements, so can be trusted. It also shows the high Q resonance Erin found at 500 Hz.

So not the best of speakers, but not the worst. However it is a difficult load. That is why your amp is heating.

I don't know why you are using an eleven channel power amp to drive two speakers, unless you are planning to add nine more. If you are you had better choose carefully.

 

[PENG]

I think the answer lies in your speakers. They have adverse impedance and phase angle curves. Not the worst, but on the difficult end. I could well understand why they would make an amp cook.

Those are Erin's measurements, so can be trusted. It also shows the high Q resonance Erin found at 500 Hz.

So not the best of speakers, but not the worst. However it is a difficult load. That is why your amp is heating.

I don't know why you are using an eleven channel power amp to drive two speakers, unless you are planning to add nine more. If you are you had better choose carefully.

Keep in mind he has the MKII, that could be worse, but I couldn't find any measurements for those.