Amp Power Requirements at Idle

[Mantana]

Some manufacturers don't publish this spec but I'm looking at
upgrading to a Musical Fidelity A1008 integrated. The power
supply has it's own separate box and this amp has a tube
preamp section. When my current MF 250W A5 is sitting in idle
with the mute on, it draws about 35 watts. The A1008
is also 250W but in idle it draws 120W. Anyone know
why it would draw so much more current ? Is it simply
because the A5 is 100% solid state and the A1008 has
tubes in the preamp?

 

[Audioseduction]

You're lucky, my Pass Labs X350.5 draws 550W @ idle.

 

[Cherian]

What??? 550 Watts at idle!! That cannot be! What is dissipating this power?

At $0.33 a kilowatt hour that amp is costing you $136.00 a month to keep idle. I hope you shut the unit off when not in use.

 

[RichTeer]

What??? 550 Watts at idle!! That cannot be! What is dissipating this power?

'Swhat the manual says! I guess they're haevily biased into Class A (though not as much as Pass' XA series of amps)...

 

[Mantana]

What??? 550 Watts at idle!! That cannot be! What is dissipating this power?

At $0.33 a kilowatt hour that amp is costing you $136.00 a month to keep idle. I hope you shut the unit off when not in use.

That's the kind of info i'm looking for. So, if i run 24/7, idling
at 120W, it's going to cost around $28 ......

By the way, Rampage is probably in the right ballpark...the Pass 150W
integrated draws 225W at idle according to their website.

 

[Cherian]

Attached is a link for what is called a Kill-A-Watt. It is a very cool device and only costs $20.00. With this you can profile your system. It measures Amps, Watts, Power Factor. I use these at work and he helps a lot.

http://www.newegg.com/Product/Produ...ctronic+Gadgets-_-P3+International-_-82715001

 

[jtwrace]

Attached is a link for what is called a Kill-A-Watt. It is a very cool device and only costs $20.00. With this you can profile your system. It measures Amps, Watts, Power Factor. I use these at work and he helps a lot.

http://www.newegg.com/Product/Produ...ctronic+Gadgets-_-P3+International-_-82715001

Thanks for that. Just ordered one...my amps are 300w idle and 800w on high bias. We'll see....

 

[Cherian]

I do not recommend having any amp on 24/7 if it has tubes in them even if it is just for the input gain section. You will burn up the tube very quickly.

 

[Mantana]

i never leave on 24/7.....i probably have them on 10-12 hrs a day
for 3 days (my days off, mostly in idle) and then 8 hrs the rest
of the week. So about 44 hrs a week.

 

[twich54]

i probably have them on 10-12 hrs a day
for 3 days (my days off, mostly in idle).

I'm curious.......why ??? if they are spending the majority of their time idling why waste the electicity ??

 

[Mantana]

I'm curious.......why ??? if they are spending the majority of their time idling why waste the electicity ??

'cause i'm in and out and listen for while and then do something else.
I thought it was better to let the amps run rather than cranking them
on and off. I just ordered the Musical Fidelity 1008 which idles at
120W rather than my A5's 35W, so i'll probably start powering
down when not in use. Does that shorten the tube life powering
on and off?

 

[Audioseduction]

What??? 550 Watts at idle!! That cannot be! What is dissipating this power?

At $0.33 a kilowatt hour that amp is costing you $136.00 a month to keep idle. I hope you shut the unit off when not in use.

I kept it on one month but my wife show the electric bill and asked why it jumped up over $100 this month. Needless to say I keep is off now.

 

[FISH_MAN]

I kept it on one month but my wife show the electric bill and asked why it jumped up over $100 this month. Needless to say I keep is off now.

that's nothing sometimes I run 2,000+ watts worth of light on a single aquarium
for 10+ hours a day!you guys think HIFI is energy hungry just go outside at hi noon by the equator. now try to reproduce that amount of light in your living room lol BTW water temp may not raise past 80 Fahrenheit. a whole other apparatus is required to maintain these parameters which is equally as inefficient

 

[Tosh]

At $0.33 a kilowatt hour that amp is costing you $136.00 a month to keep idle.

Where is electricity that expensive? We pay $0.08 per kWh here, and I remember it being about $0.14 in Florida.

 

[churchill]

My Pass X250 draws 270 watts at idle; I usually turn on about 30-45 minutes before the tunes start!

 

[SteveInNC]

Anyone know
why it would draw so much more current ? Is it simply
because the A5 is 100% solid state and the A1008 has
tubes in the preamp?

Well if you think about it, vacuum tubes are basically heater elements surrounded by some control grids. The filament has to be hot to emit electrons (Google 'thermionic emission'), and is on whenever the amp is on.

Your amp is doubling as an electric space heater.

 

[Brad225]

Well if you think about it, vacuum tubes are basically heater elements surrounded by some control grids. The filament has to be hot to emit electrons (Google 'thermionic emission'), and is on whenever the amp is on.

Your amp is doubling as an electric space heater.

Yea I get a nasty email from Al Gore each day I turn on my tube amps and have to then lower the thermostat to cool the room.

 

[vic]

Hi,
I wouldn,t worry too much about amps if you have air conditioning that will use far more power.
In my system,
AMPS,800watts each x 2(audio research ref600mkII tube monoblocs)2200watts max each
krell TAS 500 watts,3000watts max
BAT VK-500 450 watt,2000 watts
4 subs max 2400 watts each x4
Aircon for room 20KWatts/hr(20000 watts see what I mean)
aircon always on winter or summer amps put out lots of heat.
By all means when not there tubes amps should be turn off,regards victor.

 

[DrJRapp]

Hi,

Aircon for room 20KWatts/hr(20000 watts see what I mean)
aircon always on winter or summer amps put out lots of heat.

That is one HUGE air conditioner. 20KW should equate to about 15 tons...which is massive for a home. My home here in South Florida USA, which is quite large has three units totaling 11 tons. My total connected load for these three units is 9KW.

The trouble with heat producing amps such as tubes or class A solid state in a warm climate is you pay twice. Once for the electricity to run the amp, a second time for the a/c to remove the heat.

 

[twich54]

Aircon for room 20KWatts/hr(20000 watts see what I mean)

Agreed Jerry....gotta be a typo !!