Potential Defect with Yamaha RN 600 A?

[Steven Holt]

Today, the Scientific Audiophile released a video, titled, Yamaha RN600A a $900 mistake? In the video, he points out that the unit is rated at 80W at 8R and 60W at 4R. He claims that he checked this with Yamaha, and they verified it. He goes on to say that because of this, the unit may be unsafe. He gives it a DO NOT BUY rating. My question, how can this be? Isn't there an inverse relationship between resistance and power? Something about this does not feel right to me. I hope that some of our technically inclined membership will watch this video (it's on YT) and determine if this is right. It does not make sense to me.

 

[antcollinet]

8ohm needs more voltage.

4 ohm needs more current.

The lower rating at 4ohm simply means that the current rating is the limiting factor for 4ohm speakers.

It says nothing about the safety of the unit. That statement from your youtube reviewer is bunkum. He should take it down. If I were Yamaha I'd be firing up the lawyers.

EDIT : I've just watched his rather overdramatized and breathless video. As far as I can see he didn't say anything about safety, though he did say (incorrectly) that it might overheat.
EDIT SOME MORE : I've left a comment.

 

[Beave]

I'm skeptical of that specification - even though Yamaha supposedly 'confirmed' it. Maybe the receiver has a switch/selection for 8 ohm speakers or 6 (or 4?) ohm speakers, and that spec is for when the switch is set for the lower impedance - in which case the switch is basically limiting power output.

I'd like to see a pic of internals of the product, but I don't see anything online in a Google image search.

Amir measured the Yamaha R-N803 here and found much higher output wattage into 4 ohms https://www.audiosciencereview.com/...ds/yamaha-r-n803-smart-receiver-review.13830/

I would expect the 600 receiver to be similar but a little lower in power, unless they made significant changes to the amplifier section (which I doubt, considering Yamaha has been using similar amp & power supply sections in their receivers for decades).

So my guess: I'm going with the power being limited due to a selection for lower impedance speakers.

 

[DVDdoug]

He goes on to say that because of this, the unit may be unsafe.

It's highly unlikely that Yamaha is making something "unsafe".

There are various ways of calculating power (wattage) -
Power = Voltage X Current
Power = Voltage squared / Resistance
Power = Current squared X Resistance

With the same voltage, halving the resistance doubles wattage.
With the same current, halving the resistance halves the wattage.

With a "strong" well-regulated power supply, the voltage will hold-up and you simply get more current with a lower impedance load... until you go too-low and "pull" excess current and the amp goes into thermal shutdown, or burns-up, etc.

 

[Chrispy]

Who is this guy with the stuffed toy and really bad teeth and why would you listen to him about this?

 

[antcollinet]

amp goes into thermal shutdown, or burns-up, etc.

Or simply current limits. The equivalent of hitting the voltage rails - but for current. So clipping.

 

[RayDunzl]

Isn't there an inverse relationship between resistance and power?

Gotta consider voltage too.




Spec:

Quick Manual:

Probably limits voltage in the 4 ohm setting, so a lower power rating.

Might be fancy and permit higher voltage - for the dynamic rating - then chop it if it lasts too long (continuous).

 

[Steven Holt]

Maybe the receiver has a switch/selection for 8 ohm speakers or 6 (or 4?) ohm speakers,

Yes, correct, it does.

 

[Beave]

Then, as explained above, that spec is probably with that selection engaged for the lower impedance speaker setting, whereas the 8 ohm spec is with that selection switch set the other way. Selecting the low impedance on that switch probably reduces the rail voltage and thus the possible output voltage and thus output wattage. That keeps the amp from getting too hot.

With the switch kept at the 8 ohm setting, I bet it can output quite a bit more than 60 watts and probably more than 100 watts, but it might get quite hot doing so. I wonder if they skimped a little on heatsinking compared to the R-N803 mentioned above?

 

[JSmith]

Scientific Audiophile

@SimpleTheater is a member here.


JSmith

 

[antcollinet]

@SimpleTheater is a member here.


JSmith

Well apparently it is his

duty to God and country to call these companies out.

 

[restorer-john]

Surely it's just clickbait idiocy by yet another youtube clown.

Yamaha rates according to FTC regulations. That means 9/10 times they underrate the 4R power output to stay within the thermal envelope and particularly for exposed surface EU regs for 'touch' temperatures.

Sooner or later, some of these wallopers are going to get sued into oblivion by a multinational. Hopefully sooner rather than later.

 

[antcollinet]

Sooner or later, some of these wallopers are going to get sued into oblivion by a multinational. Hopefully sooner rather than later.

I've just pointed out that risk to him in his comments.

 

[IAtaman]

Today, the Scientific Audiophile released a video, titled, Yamaha RN600A a $900 mistake? In the video, he points out that the unit is rated at 80W at 8R and 60W at 4R. He claims that he checked this with Yamaha, and they verified it. He goes on to say that because of this, the unit may be unsafe. He gives it a DO NOT BUY rating. My question, how can this be? Isn't there an inverse relationship between resistance and power? Something about this does not feel right to me. I hope that some of our technically inclined membership will watch this video (it's on YT) and determine if this is right. It does not make sense to me.

Not a great piece of kit for an audiophile but having less continous output power at 4ohm does not make it unsafe. Speaking of which, I heard some click baity comments in the video but I havent heard him say unsafe actually. Maybe you recall incorrectly?

@SimpleTheater is a member here.
JSmith

Judging from this video only, one can argue Simple Theater would be a more accurate name for the channel as well.

 

[restorer-john]

Judging from this video only, one can argue Simple Theater would be a more accurate name for the channel as well.

 

[Steven Holt]

Maybe you recall incorrectly?

Yes, after suffering thru that video again, I was mistaken. He did not say the unit was unsafe, but rather that it had the potential to overheat and I inferred that it may be unsafe. My apologies. And after reading his reply to antcollinet, I'm thinking this guy is somewhat 'non compos mentis' (more plain, off his rocker). He's lost me as a viewer, I'll tell you that.

 

[restorer-john]

He did not say the unit was unsafe, but rather that it had the potential to overheat and I inferred that it may be unsafe.

Modern Yamaha, regardless of price have multiple systems for overheat protection.

In a typical Yamaha receiver/amp sold today, they have temperature sensors on the bridge rectifier, the left and right channel heatsink/output devices which are read by individual A/D lines on the microprocessor. Not only that, there are DC offset, overcurrent and short circuit protections. If all that fails, there are line fuses and a last resort one-time thermal fuse in the windings of the power transformer.

You could wrap a modern Yamaha in a blanket, play it flat out and it would still protect itself.

 

[TheBatsEar]

Yamaha RN600A a $900 mistake?

The pricing sure is.

The power supply and power amplifier are that of the R-N602. Go to their product pages and compare the specs:

R-N600A - Technische Daten - Yamaha - Deutschland

Der Yamaha R-N600A bietet die vollwertige HiFi-Technologie, die über viele Jahre entwickelt wurde, und er ist mit MusicCast kompatibel, wodurch Sie mehr Freiheit und Flexibilität beim Hören haben.

de.yamaha.com

MusicCast R-N602 - Technische Daten - Yamaha - Deutschland

Höchste Klangqualität in einem Netzwerk-Receiver mit DSD 5,6MHz Unterstützung. Kompatibel mit MusicCast und etlichen weiteren Netzwerkfunktionen. Unendlicher Zugriff auf verschiedene Audioquellen inkl. High-Res Audio, Smartdevices und Streaming-Diensten.

de.yamaha.com

It's not a bad receiver, you get some upgrades to the R-N602 (just not in the amplification department), but i don't think it's a particularly good value. Neither was the R-N602.

I would prefer a A-S501 and a Wiim streamer instead. Once the streamer becomes obsolete, you replace it, without having to replace the 501. And the 501 has a hair more power:

A-S501 - Technische Daten - Yamaha - Deutschland

Eindrucksvolle Klangqualität mit einer Vielzahl an Funktionen und einem eleganten Aussehen. Ein Vollverstärker mit den Vorzügen digitaler Eingänge.

de.yamaha.com

 

[Steven Holt]

I would prefer a A-S501 and a Wiim streamer instead.

Total agreement on that.

 

[jirkas]

Yamaha R-N600A Firmware Update Ver.1.04

1. Adapt BBC internet radio stations to new streaming technology (HLS)
2. Support Qobuz streaming service in Canada and Japan
3. Other bug fixes