power consumption

For those of us deprived of good cheap pwer in california, how does one calculate the energy usage / unit time of our audio equipment?

Can you figure it out fomr the specs alone and if so, how?


Sometimes power consumption is provided in the specs, sometimes not. If not, check with the manufacturer. I suppose it could be difficult to get from huge companies like Sony or Pioneer, but small high-end companies should be happy to provided it. Good Luck. Craig
The rating plate or handbook for each item of your equipment should give you a figure for maximum power consumption in watts. Take this figure and divide it by 1000 and this will give you the KilowattHour consumption for that item. Multiply it by the time (in whole hours or fraction of) each item of equipment is switched on for and this will give you the total consumption. Depending upon what unit of measurement your electric utility bills you in you can work out the cost of your electricity for each item. For example, if your utility bills you in "units" (where 1 unit equals 1,000 watts used in 1 hour) then say an amplifier that consumes at full rating 400 watts and is operated for 3 hours would use 400 x 3 = 1.2 KwH or 1.2 "units" of electricity. Another example: if an amp uses 1200 watts then in one hour it would use 1.2 KwH or 1.2 "units". In BTU's 1KwH (or 1 unit) equals 3,410 BTU's. Hope none of this has confused you even more...? Hope it helps, regards, Richard
Thanks Richard and Craig. To follow up, Yes I did understand everything Richard.
Now, for the better worded and more to the point question.

Does the system use more watts when it is off as opposed to actually playing and how can I find out the energy consumption when it is simply on and warm as opposed to playing and hot?

Thanks, jd
Pull the outlet out of the wall. With all your stuff on standby clamp a amp meter around the hot. This will give you your load in amperes. amps x volts = watts or amps x 120(volts)= consumed power. Richards post will do the rest. Then turn it all on crank it up and see what you've got. I'll guess twice as much power consumed. You know I own an amp meter maybe I should run a test and report the findings.
Whether the amp uses more power when playing or idling is dependent on the technology of the amp. A typical "Class A" (not to be confused with a Stereophile "A" rated) amp will use as much power idling as playing at low to medium volumes. If the amp has a standby switch, the standby mode should reduce power consumption to a very small amount. If the amp has an on/off switch, that should reduce the power consumption to nothing. If this info isn't in the manual or on the back of the unit, you'll have to get it from the mfgr, or measure it as mentioned above. To throw in a little more technicality, you'd have to use a Watt meter to get the most accurate measurement (due to phase angle), but measuring the current (amps) will get you in the ballpark.
Mrowlands: Good point. I use a Musical Fidelity X-A1 integrated amp in a guest bedroom system (also where we keep the computer) and it idles in Class A, though it switches to Class A/B at 3-5 watts output. I now turn this amp off (when not in use) even though it does not sound as good this way in order to conserve energy (we live in the LA area). I did keep this amp on 7/24 for approx. six weeks to burn in various cables and this practice was very evident on our power bills. We do not use air conditioning and such and our electrical usage is generaly the same each month. Around January we started using night lights (instead of keeping the kitchen light on at night and such) and also turn the computer off each evening, when we go to sleep. These are little things that all add up. I do leave all of the digital components on 7/24 as I feel like I have wasted my investment when I listen to them cold, but they seem to draw very little current and the amp in the main system is tube, which gets turned off when it will not be used for a couple of hours or so (I also have somewhat of a set listening schedule based on my wife's activities and both of us are home most of the time). In the good old days everything was left powered up 7/24. Anyway, other than just worrying about the gear I recommend that all power usage be given a look at which includes reajusting the wattage of incandescent light bulbs being used in various locations and anything else that can be thought of. Most flourescent fixtures use as much energy starting up each time as they do running for 4-6 hours (study done by the Des Moines, IA school district in the 60's, as I recall).
My spectral 360 amp uses 250 when just on according to the website. My Dmc 30 uses 8o watts. Given the above posts and todays prices in california that comes out to somewhere between 25 and 36 bucks a month to have it on. That is definitely noticeable. More importantly though for me is the guilt I feel when this stuff is on and using power when not being used. There are always two sides to this energy consumption problem. One is the mony it cost us and two is our responsiblity to decrease our consumption in this the most energy rapacious country in the world
I purchased a device called WattsUp several months ago to satisfy my curiousity about the real power consumption story with the PS Audio power plants. Works great, but cost about $100.

For those of us in California with Class A amps (my Pass X150 idles at 200W), don't forget that plugging it into a PS Audio Power Plant causes approximately double the power usage! And for those of you with air conditioning, don't forget that the air conditioner has to compensate for all the heat that's generated!! Since I don't have air conditioning, I've actually unplugged the Pass from the PP600 due to the heat (doh!). Maybe if I'd stop buying audio gear I could afford central air (and the electricity bill).
The Power Plant does draw extra power. But contrary to common belief, it does not double consumption, at least not in my system and by my measurements.
Drubin, I've searched the forums for the results of your measurements but can't find anything. What did you find?
Mrowlands, ...only 200w? My damned Aleph 2 monos idle at 600w!! Mounting under the floor joists in the basement helped with the heat, but there's still that energy-gulping guilt to shoulder! At least I power 'em down (didn't we used to just say "shut 'em off"?) when not in use. The one-hour warmup subtly precludes sponataneous use though, so I probably don't listen as often as I would if they were left on continuously. Oh well....
According to the Wattsup readings, The Power Plant 300 draws about 40 watts with nothing connected to it, about 43 in multiwave mode. My Pass Aleph 3 draws around 200 watts at idle (196 acutally, although I think the PAss docs say 250). Plugged into the PS Audio, the total draw is just under 300 watts. Which suggests that there is some additional overhead in there somewhere (more than 200 + 40), but not a doubling. I'll move some equipment around later and check a few other components (including my Pass X-150 ). --Dan
Question for Jdwek and Drubin (and others) - out of curiosity how much do you pay per unit for your electricity? Be interested to compare your costs with ours here in the UK, thanks, regards, Richard
Hi Richard: 12 to 13 cents per kWh for Edison Co. in LA. Our average monthly consumption is around 300 kWh's and I assume that we are quite frugal as the main consumption is from the Hifi's, the computer and the fridge (no A/C, we have gas appliances and lighting is on the light side:-).
Hello Dekay, thanks for that. Interseting as we pay around 12 cents per kWh (or unit) at peak rate (7am til midnight) and then 3 cents per kWh during the night. Plus 5% tax and also we get "stung" for high standing charges every quarter. Regards, Richard
Richard: We were eligible for a 20% (I think) discount for X amount of months usage, but went over the base line usage (the power company's estimate) and did not qualify. So, there is an incentive, in the system, to lower one's consumption. We went over due to me burning in a bunch of cable 7/24 in April and May, I am certain. I guess that this is a good example of a mute point. I wonder if the rates go higher if one uses a lot more power than we do or goes "way" over the base line? We have a neighbor who runs the A\C all day long (for her dog) and I will take a look at her bill to see if this is the case. It seems that there would be a penalty as well as a discount.
Dekay, there you go again with the hairdryer getting those tubes pre-warmed.....!!! No wonder you are over your base line usage! Regards, Richard
Richard: No hair dryers since trimming off the old Mullet 20 years ago. It's the Musical Fidelity amp that sucks the most power (not the tube amp). The MF amp also plays, at volume, for a good 10-15 seconds or so after its power has been cut. The power supply unit weighs in at 5 lb.