Someone explain this to me. I've never seen an amp specified with two different numbers for "Output Power" and "Output Wattage".

I suspect this is a marketing gimmick, and both are lies -- as is typical today. At least they didn't specify "RMS Power".

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YAMAHA R-S202BL Stereo Receiver

Product information

Connectivity Technology	Bluetooth version 4.1 + EDR
Controller Type	Remote Control
Other Special Features of the Product	Advanced circuitry design.Speaker selector for 2 systems. Input Sensitivity (CD): 500 MV/47k ohmsHead phone terminalAuto power standby functionSpeaker selector and speaker terminals for two systems
Compatible Devices	Smartphone, Tablet, Speaker, Television, Game Console
Connector Type	HDMI
Audio Encoding	Stereo
Audio Output Mode	Advanced circuitry design.Speaker selector for 2 systems. Input Sensitivity (CD): 500 MV/47k ohmsHead phone terminalAuto power standby functionSpeaker selector and speaker terminals for two systems
Surround Sound Channel Configuration	0.0, 2
Output Power	85 watts
Number of Channels	2
Output Wattage	100 watts
Supported Internet Services	streaming music services
Control Method	Remote
Audio Output Type	Speakers
Format	WMA
Wireless Technology	Bluetooth

I am in the market for a decent amp to replace the 4 year old (cheap) Pyle that quit on me. Willing to spend up to $300. 100W to 300W per channel is an acceptable power range. I'm taking suggestions from those with experience.

 

I don't fancy that 500 Megavolts on my headphones.

 

I don't fancy that 500 Megavolts on my headphones.

Funny, obviously a typo, but I have no need for headphones for this application.

 

Funny, obviously a typo, but I have no need for headphones for this application.

Put some tape over the socket just in case .. .

 

The Watt is a unit of power.
That datasheet was obviously written by a junior technician and wasn’t scrutinized by anyone knowledgeable.

An acquaintance of mine once told me that there are three types of liars;
Liars, damn liars and spec sheet writers.

 

The Watt is a unit of power.

And who says there's nothing new to learn here on AAC?

I'm looking for the answer as to why there are two different numbers, both synonymous with "Output Power".

And this is Yamaha, for Pete's sake. They've been writing spec sheets (some pretty good ones) since before I was alive.

 

Sorry I should have emphasized that the spec sheet, as published, is absolutely preposterous.

 

I found the actual manual:

https://usa.yamaha.com/files/download/other_assets/2/794512/web_VEX7420_R-S202_om_UA_En_A0.pdf

Still weird. They have lots of ways to measure power.

I miss the old days when they gave you a (single) number + distortion you could use for comparison.

 

This gives a clue. Apparently the same product is de-rated for sales in Asia.

 

This gives a clue. Apparently the same product is de-rated for sales in Asia.
View attachment 370699

Unfortunately, I don't know what "RMS" power is.

Edit: but, yes. Your comment makes sense. Looks like the Amazon copy editor blindly transcribed some numbers and made some things up along the way.

 

Help me make sense of these:

Minimum RMS output power
(8 Ω, 40 Hz to 20 kHz, 0.2% THD)
[North America, General, China, Korea, Australia and
Europe models] ................................................. 100 W + 100 W
[Asia model] ......................................................... 85 W + 85 W
• Dynamic power per channel (8 Ω/6 Ω/4 Ω/2 Ω, IHF)
....................................................... 125 W/150 W/165 W/180 W
• Maximum power per channel (4 Ω, 1 kHz, 0.7%, THD)
[Europe model] ..................................................................... 115 W
• Maximum effective output power (8 Ω, 1 kHz, 10%, THD)
[General model] ....................................................................140 W
[Asia model] .........................................................................125 W

Minimum Output Power? So I can't turn it down? (That's a joke.)

Which is the spec that counts?

 

And, let's say I wanted to compare it to this:

https://www.sony.com/electronics/su...63b8edb2b154409daa55875111f95e4/47269071M.pdf

 

I'd say the Sony is a better model because it is rated down to 10Hz, even though it's 1% (5x the Yamaha) THD at 100W. Fair?

 

Anyone remember the 70s where we'd see output specified as "music power"?

 

Help me make sense of these:

Minimum RMS output power
(8 Ω, 40 Hz to 20 kHz, 0.2% THD)
[North America, General, China, Korea, Australia and
Europe models] ................................................. 100 W + 100 W
[Asia model] ......................................................... 85 W + 85 W
• Dynamic power per channel (8 Ω/6 Ω/4 Ω/2 Ω, IHF)
....................................................... 125 W/150 W/165 W/180 W
• Maximum power per channel (4 Ω, 1 kHz, 0.7%, THD)
[Europe model] ..................................................................... 115 W
• Maximum effective output power (8 Ω, 1 kHz, 10%, THD)
[General model] ....................................................................140 W
[Asia model] .........................................................................125 W

Minimum Output Power? So I can't turn it down? (That's a joke.)

Which is the spec that counts?

I usually look at RMS power as the prime spec for power amps but brands rate receivers differently because they don't expect most people to be listening in studio conditions. Some (that cater to the Audiophiles) like low distortion in the spec and others (big box pushers) like more power on the paper. At normal listening levels in a house IMO it doesn't matter with modern equipment at your price point. Your speakers, placement and room modes will make the difference.

Here's the power spec for my Denon AVR.


Power consumption: 660 W

I have separate bass amplification so the receiver never gets to play the low stuff.

 

Back in the 1970s in Britain, there was a firm named ILP who made a killing with power amp modules that had great spec and low price, I put an amp together using one, for a punk rock band in Liverpool, I needed very few components:

 

Back in the 1970s in Britain, there was a firm named ILP who made a killing with power amp modules that had great spec and low price, I put an amp together using one, for a punk rock band in Liverpool, I needed very few components:

View attachment 370702

This helps me how?

 

This helps me how?

You can find some on ebay quite often.

 

I'd say the Sony is a better model because it is rated down to 10Hz, even though it's 1% (5x the Yamaha) THD at 100W. Fair?

To compare green apples to green apples, I have always used the Watts RMS @ 1% THD power spec. It is a realistic, reliable and consistent power measurement method. The other methods provide unrealistic or unpredictable power levels.

 

Back in the 1970s in Britain, there was a firm named ILP who made a killing with power amp modules that had great spec and low price, I put an amp together using one, for a punk rock band in Liverpool, I needed very few components:

View attachment 370702

What happened to that company?
When I was an EE student in the 1970s, I built several of these for friends.
They would advertise in US electronics magazines. Then suddenly, they disappeared.