# Am I wasting energy by leaving my stereo on? **URL:** \ **Category:** Factual Questions\ **Created:** [May 29, 2005, 5:08pm UTC](https://boards.straightdope.com/t/am-i-wasting-energy-by-leaving-my-stereo-on/305996 "2005-05-29T17:08:01Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![tracer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tracer/32/20578_2.png) [@tracer](https://boards.straightdope.com/u/tracer)\ **Post date:** [May 29, 2005, 5:08pm UTC](https://boards.straightdope.com/t/am-i-wasting-energy-by-leaving-my-stereo-on/305996/1 "2005-05-29T17:08:01Z")
I know that a typical stereo might be rated as, say, 200 Watts. I also know that this 200 Watt rating doesn’t refer to the amount of power it typically consumes, it refers to the **maximum** amount of power the amplifier can send to the speakers when a loud “spike” occurs in the signal. (I’m talking about a spike that lasts for only a couple of milliseconds, when the waveform being sent to the speakers has a big peak in it.) So, what I want to know is, how many Watts does a typical stereo consume when it’s turned on and “listening” to an outside unamplified source that’s plugged into it, but said source is not producing any significant signal. (I.e. when the stereo is on by not amplifying anything, and the speakers are quiet.) Am I running up my electric bill unnecessarily by leaving my stereo on at night? (And, no, I don’t have one of those old stereos that uses vacuum tubes. 😛 ) ---
**Author:** ![mks57](https://avatars.discourse-cdn.com/v4/letter/m/b9bd4f/32.png) [@mks57](https://boards.straightdope.com/u/mks57)\ **Post date:** [May 29, 2005, 5:18pm UTC](https://boards.straightdope.com/t/am-i-wasting-energy-by-leaving-my-stereo-on/305996/2 "2005-05-29T17:18:43Z")
> [@tracer](#): > > So, what I want to know is, how many Watts does a typical stereo consume when it’s turned on and “listening” to an outside unamplified source that’s plugged into it, but said source is not producing any significant signal. (I.e. when the stereo is on by not amplifying anything, and the speakers are quiet.) Am I running up my electric bill unnecessarily by leaving my stereo on at night? It depends on a lot of things, but it probably isn’t consuming much power. You can get a rough idea by feeling how much heat it is producing. Almost all of the electricity consumed by your stereo ends up as heat. ---
**Author:** ![KlondikeGeoff](https://avatars.discourse-cdn.com/v4/letter/k/3e96dc/32.png) [@KlondikeGeoff](https://boards.straightdope.com/u/KlondikeGeoff)\ **Post date:** [May 30, 2005, 11:25pm UTC](https://boards.straightdope.com/t/am-i-wasting-energy-by-leaving-my-stereo-on/305996/3 "2005-05-30T23:25:21Z")
> [@tracer](#): > > I know that a typical stereo might be rated as, say, 200 Watts. I also know that this 200 Watt rating doesn’t refer to the amount of power it typically consumes, it refers to the **maximum** amount of power the amplifier can send to the speakers when a loud “spike” occurs in the signal. (I’m talking about a spike that lasts for only a couple of milliseconds, when the waveform being sent to the speakers has a big peak in it.) > > So, what I want to know is, how many Watts does a typical stereo consume when it’s turned on and “listening” to an outside unamplified source that’s plugged into it, but said source is not producing any significant signal. (I.e. when the stereo is on by not amplifying anything, and the speakers are quiet.) Am I running up my electric bill unnecessarily by leaving my stereo on at night? > (And, no, I don’t have one of those old stereos that uses vacuum tubes. 😛 ) The manual for the amplifier should, under Specifications, list the amps used under power and idle, check it out. A solid state device will not really use that much power when not playing anything. There is a lot of wear and tear on the capacitators and other elements by turning it on and off. So, if you really use it every day, then it might give it a longer life if you just turn down the volume and leave it on. If you are not going to use it for several days, then turn it off. ---
**Author:** ![tracer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tracer/32/20578_2.png) [@tracer](https://boards.straightdope.com/u/tracer)\ **Post date:** [June 4, 2005, 12:53am UTC](https://boards.straightdope.com/t/am-i-wasting-energy-by-leaving-my-stereo-on/305996/4 "2005-06-04T00:53:29Z")
> [@KlondikeGeoff](#): > > The manual for the amplifier should, under Specifications, list the amps used under power and idle, check it out. Unfortunately, this stereo is an old model I picked up used at a garage sale 13 years ago. (And when I say “old”, I mean it has a built-in **eight-track tape player** , fer cryin’ out loud.) The previous owners had thrown out the manual long ago. > [@](#): > > So, if you really use it every day, then it might give it a longer life if you just turn down the volume and leave it on. Will turning down the volume actually make a difference in terms of power consumption, if there’s no input signal to begin with? ---
**Author:** ![rfgdxm](https://avatars.discourse-cdn.com/v4/letter/r/c0e974/32.png) [@rfgdxm](https://boards.straightdope.com/u/rfgdxm)\ **Post date:** [June 4, 2005, 1:00am UTC](https://boards.straightdope.com/t/am-i-wasting-energy-by-leaving-my-stereo-on/305996/5 "2005-06-04T01:00:13Z")
The simple answer is yes. Odds are it consumes over 100 watts and hour constantly. As someone already posted, likely as heat. ---
**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\ **Post date:** [June 4, 2005, 2:32am UTC](https://boards.straightdope.com/t/am-i-wasting-energy-by-leaving-my-stereo-on/305996/6 "2005-06-04T02:32:26Z")
> [@tracer](#): > > Will turning down the volume actually make a difference in terms of power consumption, if there’s no input signal to begin with? Nope. It’s still gonna suck down a lot of power doing nothing, especially if its an older stereo. If it’s got an 8 track then it’s also got lots of old fashioned discrete transistors all over the place. There’s no way of telling how much power it will consume at idle, but I’d guess somewhere around 20 watts probably isn’t going to be far off the mark.