How much electricity does a hifi amp use?
Discussion
How much electricity does a hi-fi amp use when:
- doing nothing - just switched on at the mains
- amplifying something
I've had my ancient Naim pre/power amp switched on continuously for the last 30 years. Connected to my PC for the last 20.
I'm hoping that it costs pennies per day. I suspect I may have noticed if it was £s.
I find the Windows start-up sound has an ethereal quality using this setup for my PC speakers (big 30+ year old Linn ones - can't remember the name). And the "new email received" ding, although lacking some colour transparency at the extremes of the spectrum, has a playful quality that dominates its almost infinite sound stage. Am I doing this right?
- doing nothing - just switched on at the mains
- amplifying something
I've had my ancient Naim pre/power amp switched on continuously for the last 30 years. Connected to my PC for the last 20.
I'm hoping that it costs pennies per day. I suspect I may have noticed if it was £s.
I find the Windows start-up sound has an ethereal quality using this setup for my PC speakers (big 30+ year old Linn ones - can't remember the name). And the "new email received" ding, although lacking some colour transparency at the extremes of the spectrum, has a playful quality that dominates its almost infinite sound stage. Am I doing this right?
Over on Pinkfishmedia and the Naim forum this question has been asked a few times. Maybe look there for an answer.
I leave my Naim on except when we go away or if there’s a high lightning risk.
We have solar panels so the cost is nil during the day, very little over night on cheap rate.
I’ve a ‘thing’ about power switches failing due to thousands of operations.
I leave my Naim on except when we go away or if there’s a high lightning risk.
We have solar panels so the cost is nil during the day, very little over night on cheap rate.
I’ve a ‘thing’ about power switches failing due to thousands of operations.
It depends on the draw at each point. Off, it will probably be only a few watts, maybe 6 or 8. If you had it on for 24 hours that would be 192 Watts. At 14p per kilowatt or similar thats about 3p.
When on it will depend on how loud it is. Full blast 30watts, 3 hours per day 240watts in total, so again, not a lot of money.
When on it will depend on how loud it is. Full blast 30watts, 3 hours per day 240watts in total, so again, not a lot of money.
Camelot1971 said:
My Arcam AVR850 is class G and uses around 100w at idle (less then 1w when in standby). I'd expect a class A/B amp idling would use quite a bit less than that. If it's cool/cold to the touch while at idle it can't be using much power.
Class G uses (near enough) the same amount of power as Class A/B at idle.It's a commutating system - there are multiple HT power rails (usually two sets but can sometimes be more), and as the power demand rises, additional HT rails are switched in via commutating diodes.
But the idle current is otherwise the same as Class A/B - this is the whole point of Class G.
However I'd be very surprised if it uses 100W at idle - it's a 7 channel receiver so that would indicate that each channel is idling at 14 watts each.
TonyRPH said:
Camelot1971 said:
My Arcam AVR850 is class G and uses around 100w at idle (less then 1w when in standby). I'd expect a class A/B amp idling would use quite a bit less than that. If it's cool/cold to the touch while at idle it can't be using much power.
Class G uses (near enough) the same amount of power as Class A/B at idle.It's a commutating system - there are multiple HT power rails (usually two sets but can sometimes be more), and as the power demand rises, additional HT rails are switched in via commutating diodes.
But the idle current is otherwise the same as Class A/B - this is the whole point of Class G.
However I'd be very surprised if it uses 100W at idle - it's a 7 channel receiver so that would indicate that each channel is idling at 14 watts each.
If anyone wants a definite answer, you can buy a clamp-on meter from ebay etc. The easiest way to measure the current consumed by a device is to turn it on, then put the clamp meter on your single line feed to the consumer unit or meter. Measure the value, then switch off or unplug the amp or whatever. Measure current again, subtract one from the other and multiply by 230. That's the power it was taking.
And that's just one way of passing ten minutes during lockdown...
And that's just one way of passing ten minutes during lockdown...
Camelot1971 said:
That's what Arcam quote in the manual and on their website. It feels about right - its quite warm even just idling.
If you've ever felt an amp dissipating 100w from the heatsinks you might think differently.You simply can't touch them (or even the case in the near vicinity).
It would be interesting to see for sure if it really does draw that much power though, as that's into small class A amp territory.
TorqueDirty said:
If it is a Class A amp it will draw a lot of current even in idle as I understand it - but it will also keep your room nice and warm!
I know people say this, but I have a sugden IA4, and it never really gets what I would call hot, warm at best.If course I dont leave it on permanently, but after 4 or so hours use its still only warm to the touch
Europa Jon said:
If anyone wants a definite answer, you can buy a clamp-on meter from ebay etc. The easiest way to measure the current consumed by a device is to turn it on, then put the clamp meter on your single line feed to the consumer unit or meter. Measure the value, then switch off or unplug the amp or whatever. Measure current again, subtract one from the other and multiply by 230. That's the power it was taking.
And that's just one way of passing ten minutes during lockdown...
I have a dedicated consumer unit for the HiFi and an Owl thingy on the feed into the CU. The pics show a sad story for my electricity billAnd that's just one way of passing ten minutes during lockdown...
CD and Preamp on via two PS Audio P5:
plus Power amp start-up surge (hardwired dedicated spurs direct to CU):
CD, Pre and Power Amps all idling:
So power amps are idling at a little over 500 watts. As they warm up, the wattage drops slightly, so my guess is that 500 watts is the actual figure. They are type AB and, apparently are biased towards a fairly high class A component.
The following from Pass Labs is quite interesting:
https://www.passlabs.com/technical_article/leaving...
I don't want to break any forum rules by selectively quoting from the article, but if you read far enough, it gives an indication of output power against power consumption, based on bias level. Pass Labs amps are known to have a very high class A bias (probably similar to mine), so I'd guess Arcam would probably be at the low end of the class A bias range.
Edited by ian996 on Thursday 11th February 10:30
TonyRPH said:
Camelot1971 said:
That's what Arcam quote in the manual and on their website. It feels about right - its quite warm even just idling.
If you've ever felt an amp dissipating 100w from the heatsinks you might think differently.You simply can't touch them (or even the case in the near vicinity).
It would be interesting to see for sure if it really does draw that much power though, as that's into small class A amp territory.
Arcam do say the first 20w or so of their Class G amps operate in Class A (I know they are not purely Class A). The A49 has the first 50w in Class A!
Camelot1971 said:
While I can't touch the heatsink inside (it's pretty hefty - it must weigh around 7kg) the whole case gets warm when idling. 14w per channel at idle doesn't seem unrealistic. When operating and watching a film it gets hot on the top. My room will usually go from 20c to 25c (5mx4m) while watching a film!
Arcam do say the first 20w or so of their Class G amps operate in Class A (I know they are not purely Class A). The A49 has the first 50w in Class A!
Interesting, removes the need for a room heater then!Arcam do say the first 20w or so of their Class G amps operate in Class A (I know they are not purely Class A). The A49 has the first 50w in Class A!
Road2Ruin said:
It depends on the draw at each point. Off, it will probably be only a few watts, maybe 6 or 8. If you had it on for 24 hours that would be 192 Watts. At 14p per kilowatt or similar thats about 3p.
When on it will depend on how loud it is. Full blast 30watts, 3 hours per day 240watts in total, so again, not a lot of money.
The last NAIM digital range, Unitiqute and so on, when on standby still used loads of leccy.When on it will depend on how loud it is. Full blast 30watts, 3 hours per day 240watts in total, so again, not a lot of money.
They fixed it in the new Nova range (as a new feature, of course).
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