Class D Amps and very surprising Electric Bill !!

[mgkwackerd]

This year I've gone over to complete Class D amps, and I find this interesting.

Lounge = Primare Pre 32, CD22 and 2x A34.2 monoblocked. These replaced a cyrus 6 box system DACXP+, CDXT, 2x PSXR's and 2x MonoX 200's

Study = Primare I22 replacing Rotel RA-11

Just had my electric bill and it is £257 cheaper than last year (billed every 6 months) so I investigated, the lounge system runs about 10 hours a day and the Cyrus consumption is rated at 1548 watts per hour, Primare just 98 watts, so a typical day at 25 pence (approx) per kilowatt, cyrus cost £3.87 and primare £0.245 pence, so the Primare only uses about 7% of the electric the cyrus did and in the study it is about 9%, - Rotel 220 watts vs Primare 19 watts.

Over a 10 year period, that's over £5000 going to be saved, as I've cut consumption by about 92% (only hi-fi)

And, I'm more impressed with the cleaness, clarity and imaging of the primare, so a win, win situation. I was never really happy with the detailing of the cyrus, that's why I swapped, as the previous purchase, I22 made my Kef LS50's really sing. The A34.2's make my R500's sing.(550w/c) (how do they do that when they only consume 24watts ???) I'm not technical at all !!

NEVER considered this when I auditioned them, just went on the sound I liked, so this is a real bonus.

Happy chappy.

 

[Broner]

This year I've gone over to complete Class D amps, and I find this interesting.

Lounge = Primare Pre 32, CD22 and 2x A34.2 monoblocked. These replaced a cyrus 6 box system DACXP+, CDXT, 2x PSXR's and 2x MonoX 200's

Study Primare I22 replacing Rotel RA-11

Just had my electric bill and it is £257 cheaper than last year (billed every 6 months) so I investigated, the lounge system runs about 10 hours a day and the Cyrus consumed 1548watts per hour, Primare just 98 watts, so a typical day at 25 pence (approx) per kilowatt, cyrus cost £3.87 and primare £0.245 pence, so the Primare only uses about 7% of the electric the cyrus did and the study is about 9%, Rotel 220 watts vs Primare 19 watts.

Over a 10 year period, that's over £5000 going to be saved, as I've cut consumpion by about 92% (only hi-fi)

And, I'm more impressed with the cleaness, clarity and imaging of the primare, so a win, win situation. I was never really happy with the detailing of the cyrus, that's why I swapped, as the previous purchase, I22 made my Kef LS50's really sing. The A34.2's make my R500's sing.(550w/c) (how do they do that when they only consume 24watts ???) I'm not technical at all !!

NEVER considered this when I auditioned them, just went on the sound I liked, so this is a real bonus.

Happy chappy.

When I look up your six Cyrus components I come to a combined maximum power use of 1523,5 watts, but during normal use it should be way less than that. Are you sure you're not confusing maximum power consumption with actual power consumption?

 

[chebby]

We save about £60 per year after changing from Naim seperates (Nait 5i, CD5i, NAT05) to a class D system.

Because I work mostly from home the system gets used up to 12 hours per day.

 

[mgkwackerd]

Technical I am not.

I just looked into it because nothing else has changed in my house except the hi-fi, and my bill was very much less than I expected it to be, I only have the bill to go on. Also last year I was quite ill and the Cyrus was probably running more than 10 hours a day for about 10-12 weeks, and I used this year to compare with last year.

I assumed the consumption, (from manufacturers manuals) not fact, all I know is I've saved quite a lot of money.

Someone else may enlighten me ! A techie head !!!

 

[mgkwackerd]

Chebby, do you think the Naim would be about 3-400 watts, they quote v/a and I cant work it out ?

If so, then that would be less than a quarter of my old Cyrus, I can't believe my bill, to be honest.

I've just swapped my LS50's for Revel M106's and, now seeing this saving in electric I'm going to indulge myself and get another A34.2 and use the I22 as a pre-amp and drive the revels with much more vigour.

They are a much more punchy and expressive speaker, a lot more engaging than the Kef, and fill the room much easier, should be even better with twice the juice to drive them.

I was seriously considering the Kef Ref 3, for the lounge but at £7.5k, I feel it is too expensive, so I'll just get the A34.2 for the study and put Hi-Fi on hold and change the car, as it is now over 12 months old.

My Hi-Fi is now nice, and with the addition of the A34.2 for the study, I can listen all day long and not feel underwhelmed by the kit I'm using, so job well done.

Might replace the technics SLB210 with a rega or project though, but very rarely listen to vinyl in the study.

 

[busb]

I'm not surprised - classed D are very efficient. The A34.2 is also exceptional for its SQ - considerably better than my i21 which will be gracing my GF's flat along with my SL6's.

 

[Covenanter]

If your kit was actually consuming 1.5kW you'd scarcely need any heating! That's an electric fire not a hifi.

Chris

 

[CnoEvil]

I'm not surprised - classed D are very efficient. The A34.2 is also exceptional for its SQ - considerably better than my i21 which will be gracing my GF's flat along with my SL6's.

Good to see the "old girls" being made feel useful again!

 

[BigH]

25p per kilowatt time you switched, I thought 16p was bad. As said if you are running at 1.5Kw then you dont need so much heating in winter.

 

[mgkwackerd]

Yes, this post has left me open to ridicule, so have just checked on line, I pay 16.82p/kw and my electric usage is currently down by 37% compared to last year, and nothing has changed except my hi-fi, so I'm happy !!

so 37% I think is still quite remarkable !!

 

[CnoEvil]

Does anyone know?

I know that Class A isn't green!! *sad*

 

[Broner]

I’ve googled a bit (power+consumption+amplifier) but I haven’t found a satisfactory answer to the question how much power an amplifier typically uses in a domestic setting. There are (as far as I can see) two factors at play:

-volume (more volume requires more power, but to which degree does that influence the actual power consumption of an amplifier)

-efficiency of the amplifier

Let’s say one uses the set of the OP for background music. How much of their rated power would the amplifiers actually use? Would it be like 80% or maybe 50% or maybe 20%? Does anyone know?

 

[nopiano]

I’ve googled a bit (power+consumption+amplifier) but I haven’t found a satisfactory answer to thed question how much power an amplifier typically uses in a domestic setting. There are (as far as I can see) two factors at play:

-volume (more volume requires more power, but to which degree does that influence the actual power consumption of an amplifier)

-efficiency of the amplifier

Let’s say one uses the set of the OP for background music. How much of their rated power would the amplifiers actually use? Would it be like 80% or maybe 50% or maybe 20%? Does anyone know?

I think the problem is finding something 'typical'. My Krell integrated amp uses close to sixty watts on standby, and yes it is warm. But that is a fifteen year old design.

Another mag reports the Marantz PM8005, which costs £999 and produces 100 watts, consumes 31 Watts at idle and 268 W at max. The matching CD player uses ten Watts. These are 2014 models. One hundred Watts for typical running would seem reasonable.

I would expect Class D to use least and Class A the most.

 

[Covenanter]

Yes, this post has left me open to ridicule, so have just checked on line, I pay 16.82p/kw and my electric usage is currently down by 37% compared to last year, and nothing has changed except my hi-fi, so I'm happy !!

so 37% I think is still quite remarkable !!

It's not ridicule, just disbelief. There's some other factor you are not taking into account.

Chris

 

[mgkwackerd]

I spoke to a friend today and talked about this, he has a meter than can be put on the consumer unit that measures the spike when an appliance or system is turned on, and then runs. He's bringing it over to try.

Only problem is my Cyrus system and Rotel amp have long gone.

Also the lounge has a dedicated spur R/F & E/M shielded from the consumer unit to a mains conditioner, I remember when it went in, it had to be 15A because of the cyrus ratings, I have no idea what the conditioner consumes either, but that is a constant anyway that would have been the same on both, I think.

This is over my head, I just know I'm saving money with Class D.

 

[Jota180]

Does anyone know?

I know that Class A isn't green!! *sad*

The way the EU is going by limiting the power of vacuum cleaner's motors and moving onto limiting the likes of hair dryers power I can see them legislating on amplifiers in the future.

They will go through the entire domestic electrical appliances catalogue and look to limit the maximum power usage of all of them.

Class D will be the amps they rally behind.

 

[CnoEvil]

The way the EU is going by limiting the power of vacuum cleaner's motors and moving onto limiting the likes of hair dryers power I can see them legislating on amplifiers in the future.

They will go through the entire domestic electrical appliances catalogue and look to limit the maximum power usage of all of them.

Class D will be the amps they rally behind.

I agree.

Plasmas are another power guzzler.

 

[Broner]

Does anyone know?

I know that Class A isn't green!! *sad*

The way the EU is going by limiting the power of vacuum cleaner's motors and moving onto limiting the likes of hair dryers power I can see them legislating on amplifiers in the future.

They will go through the entire domestic electrical appliances catalogue and look to limit the maximum power usage of all of them.

Class D will be the amps they rally behind.

The EU does what must be done to prevent the destruction of the planet, but quite frankly I fear it's too little too late considering that with our western lifestyle we need 4 earths to make our consumption patterns last. The only thing that makes it possible right now is the enormous difference in wealth, but China and many other countries are catching up and because their levels of consumption are rising they are easily offsetting all the green steps we are taking here.

 

[TrevC]

Does anyone know?

I know that Class A isn't green!! *sad*

The way the EU is going by limiting the power of vacuum cleaner's motors and moving onto limiting the likes of hair dryers power I can see them legislating on amplifiers in the future.

They will go through the entire domestic electrical appliances catalogue and look to limit the maximum power usage of all of them.

Class D will be the amps they rally behind.

I doubt there's all that much difference in consumption between low bias class AB and class D.

 

[andyjm]

Technical I am not.

I just looked into it because nothing else has changed in my house except the hi-fi, and my bill was very much less than I expected it to be, I only have the bill to go on. Also last year I was quite ill and the Cyrus was probably running more than 10 hours a day for about 10-12 weeks, and I used this year to compare with last year.

I assumed the consumption, (from manufacturers manuals) not fact, all I know is I've saved quite a lot of money.

Someone else may enlighten me ! A techie head !!!

All the power that goes down the mains lead to the amp ends up as heat - either in the amp itself, losses in the speaker cables and voicecoil, or in the walls and furnishings in the room where the sound is absorbed.

How good the amp is at converting input power to output power is amp's efficiency. The efficiency of the amp is = (power out to speakers) / (power down the mains lead) x 100

Class A has efficiency in the 30% range, B 70% and D above 90%.

Heating effect (and electricity bills) are all about average power, not transient peaks. Unless you are in a concert hall, your system will be producing a few 10s of watts on average. So, using the efficency ratios above, your system may be drawing 100 watts or so.

Whatever has caused the change in you electricity bills, it isn't the change in amplifier.

 

[stege]

I used to listen to a 50W amplifier hooked on a torroidal PS driven cd-player and got a draw of about 330W (reported by my APC ups).

Now I listen to a class D 2x30W hooked on the same speakers and cd-player. And I'm only seeing 20W draw, at best, on the very same ups.

I'm just saying..

 

[Covenanter]

I used to listen to a 50W amplifier hooked on a torroidal PS driven cd-player and got a draw of about 330W (reported by my APC ups).

Now I listen to a class D 2x30W hooked on the same speakers and cd-player. And I'm only seeing 20W draw, at best, on the very same ups.

I'm just saying..

In the second case you have invented a perpetual motion machine and are now the richest man in the world!

I guess what you mean is that the class D amp manual says it is 2 x 30 Watts and not that it is putting out 60 Watts of power.

Chris

 

[andyjm]

To be fair, I did gloss over some of the technicalities in my post above. The efficiencies for amps I quoted assume that the amp is delivering its rated power, which in domestic situations it is not.

The reason that this matters is that amps have a power draw no matter how much power is being delivered to the speakers. With the volume control all the way down, there are still internal losses in power supplies and circuitry in the amp drawing power. In the case of class A where the output stages are in continual conduction, this can be significant.

So, as you turn the volume down, your amp may draw less power, but it is becoming less efficient. At zero volume, the efficiency of the amp is 0% - all the input power is wasted.

 

[Sliced Bread]

If your kit was actually consuming 1.5kW you'd scarcely need any heating! That's an electric fire not a hifi.

Chris

Got to be quote of the week