Yamaha m-5000 consumes more power than a class a amp? Am I looking at this right?

[dman777]

Looking at the class A Luxman 595... it uses 330W

L-595ASE | INTEGRATED AMPLIFIERS | PRODUCTS | LUXMAN | Seeking higher sound quality

www.luxman.com

Looking at the Yamaha M 5000, it uses between 400 to 800 watts

M-5000 - Specs - Yamaha - United States

With more than 130 years of experience, Yamaha has grown to become the world's leading sound company. The M-5000 embodies this spirit with time-honored craftsmanship and market-leading innovation and serves as the epitome of high-fidelity audio reproduction.

usa.yamaha.com

Does this mean that the Yamaha actually consumes significantly more power than the Luxman class A? I thought this was strange since class a/b are supposed to be more efficient.

 

[GXAlan]

The Luxman takes in 330W and then spits out 30Wx2 into 8.

The Yamaha takes in 400W and then spits out 100Wx2 into 8.

The actual numbers don’t matter because how someone rates consumption and how someone rates output can be different. It only helps to compare within a brand.

But that is how you have more consumption and more efficiency.

 

[dman777]

Oh I see. Since I started this hobby, my electric bill has been about $40 more a month. That's with me alternating between the Luxman and Yamaha 3200.

If I got the Yamaha 5000, would it run my electric bill up higher than the Luxman 595?

 

[nerdstrike]

So, very roughly 120 hours of listening in a month?

I was of the simplistic impression that AB amps always pull their class A power and only dip into the B stage as required. Hence a bigger AB amp might use more power but probably not proportionately with the maximum output. On the other hand you might use more volume if you've got it...

 

[MaxwellsEq]

If you have a very inefficient amplifier (like a class A amp), your electrical consumption depends only on how long you listen. If you have a very efficient amplifier (like a Class D) your electrical consumption depends on how long you listen as well as how loud you listen). Class AB is somewhere in between.

 

[antcollinet]

For class A or Class AB, what will matter most for your electricity bill will be the idle power consumption. Playing music - even at moderately loud volumes will only add a few watts to this.

If you have one (if you haven't, get one) a small plugin power meter (maybe around $10 to $20) and use it to check the idle power (no music playing - or power at very low volume music playing in case they have an automatic standby function). This will tell you idle power.

And switch the amp off if you are not using it.

 

[dman777]

For class A or Class AB, what will matter most for your electricity bill will be the idle power consumption. Playing music - even at moderately loud volumes will only add a few watts to this.

If you have one (if you haven't, get one) a small plugin power meter (maybe around $10 to $20) and use it to check the idle power (no music playing - or power at very low volume music playing in case they have an automatic standby function). This will tell you idle power.

And switch the amp off if you are not using it.

For the Yamaha m-5000, am I reading it right that idle power (no music playing) is 400 watts?

 

[RayDunzl]

There are various inexpensive meters you can use to measure actual consumption and calculate usage costs...

https://www.google.com/search?q=kill+a+watt

 

[martin900]

400W idle is technically impossible for a Class AB amp of this size, the M-5000 doesn't even seem to be able to dissipate that much heat over it's heatsinks.
Must've been measaured differently, maybe something like 400W @ 50% output power and 800W @ 100% output power.

I've had a class A amp (Gryphon Antileon) that would consume 450W idle in lowest bias setting and about 850-900W idle in 100% pure class A.
Except the Gryphon was about 2-3 times the size of that Yamaha, especially the heatsinks.

 

[mcdn]

You’re just reading too much into the specs. It’s rated at 200 watts per channel into 4 ohms, and the specs say 400 watts typical / 800 max. standby consumption is 0.2 watts. That’s it. It won’t idle at 400.

 

[ahofer]

Can we just add that the worst inefficiency throughout all of this debate here and in another thread is keeping the amps on 24/7 because that allegedly makes them sound better.

People susceptible to the Class A stuff seem more susceptible to the warm-up silliness.

 

[Chr1]

Can we just add that the worst inefficiency throughout all of this debate here and in another thread is keeping the amps on 24/7 because that allegedly makes them sound better.

People susceptible to the Class A stuff seem more susceptible to the warm-up silliness.

There is also thermal cycling to consider regardless of the class of amplifier however. Probably not a good idea to power cycle amplifiers excessively. Definitely more of an issue with class A but still a consideration. How much is a judgment call. Reckon that utimately it doesn't make much sense using an amplifier that has a very high idle draw unless you are using most of its power too.

 

[antcollinet]

For the Yamaha m-5000, am I reading it right that idle power (no music playing) is 400 watts?

I doubt it.

 

[Deleted member 48726]

Looking at the class A Luxman 595... it uses 330W

L-595ASE | INTEGRATED AMPLIFIERS | PRODUCTS | LUXMAN | Seeking higher sound quality

www.luxman.com

Looking at the Yamaha M 5000, it uses between 400 to 800 watts

M-5000 - Specs - Yamaha - United States

With more than 130 years of experience, Yamaha has grown to become the world's leading sound company. The M-5000 embodies this spirit with time-honored craftsmanship and market-leading innovation and serves as the epitome of high-fidelity audio reproduction.

usa.yamaha.com

Does this mean that the Yamaha actually consumes significantly more power than the Luxman class A? I thought this was strange since class a/b are supposed to be more efficient.

The Yamaha probably uses between 60-80 Watts in idle mode. And below 0.5 Watts in standby (switched off) as its design is somewhat identical to all the other A-Sxxx models. I know my A-S1000 consumes 72 Watts idle. How they get the quoted consumption specs are not clarified.

 

[ahofer]

Probably not a good idea to power cycle amplifiers excessively.

But that is wear and tear, not energy efficiency, unless I misunderstand you.

 

[DVDdoug]

I was of the simplistic impression that AB amps always pull their class A power and only dip into the B stage as required.

Something like that. But It's probably only consuming around 1W "class A" while idling. There is a small "bias current" through the output transistors/MOSFETs while idling. Most of the wasted power when idling is probably consumed in the power supply and just "running" the amplifier, not class A/B bias current. When the class A/B amplifier starts putting-out voltage & current the transistors/MOSFETs waste power (and heat-up) when they are partially-on (creating the waveform). Once it starts putting-out "real power" and when it's not near the zero-crossing, only the positive or negative transistor/MOSFET is on, and there is no bias through the other device.

With a class-A amplifier, the transistor/MOSFET is half-on when idling which is basically "worst case" for wasting power and heating-up the device. (IMO - It's a "dumb design" for a power amplifier, but OK for a preamp or other low-power device.)

With class-D the transistors/MOSFETs switch on & off and are never "partially on" so they waste very little energy and generate very little heat. They aren't perfect switches and the don't turn on & off in zero-time so they are partially-on for microseconds, and they don't actually turn fully-on, so they do generate some heat. The light switches in your house are (nearly) perfect switches so they don't get hot or waste energy when on or off. But like any circuit, it takes power just to "run the amplifier" even with nothing coming out to the speakers.

 

[popej]

IMHO for Yamaha "Power Consumption 400W" is what you can get at normal use, playing music near clipping. My guess is, that playing at moderate volume will take less power, maybe 50-100W average. "Maximum Power Consumption 800W" is what you can get doing power test with sinus signal.

 

[Chr1]

But that is wear and tear, not energy efficiency, unless I misunderstand you.

Indeed. I guess my point is that there's a compromise between wear and tear and energy used. Keep reading "just switch it off when not in use", but don't think it's a good idea to power cycle excessively as thermal cycling can help lead to failure in the long term.

 

[Deleted member 48726]

Indeed. I guess my point is that there's a compromise between wear and tear and energy used. Keep reading "just switch it off when not in use", but don't think it's a good idea to power cycle excessively as thermal cycling can help lead to failure in the long term.

I'm pretty sure temperature is electrolytics' biggest enemy. It's chemical after all. So I wouldn't worry about switching gear on or off when needed.

 

[ahofer]

I'm pretty sure temperature is electrolytics' biggest enemy. It's chemical after all. So I wouldn't worry about switching gear on or off when needed.

I'm not an EE, but I'm curious as to how much electronics manufacturers can build in some protection in regular shutdown.

I used to have VTL tube amps, and I was convinced to invest in a vari-AC to bring power on gradually in order to save tube life. Not sure it helped that much, but it was fun to turn the huge knob.