#1


I'll keep it short - If I have a 575w RMS rated amp (Ashdown ABM C115) running at low volume, does it consume less electricity than at full volume? If so, by roughly how much?

Getting worried about bills!


Cheers
#2
Yes. Not sure on how much, but I would guess that it's somewhere around the same percentage as the difference in numbers. For example, volume at 10 consumes x amount of energy, volume at 2 consumes approximately 20% of x amount of energy. I don't know if that's true, but it's a guess.


Edit: Well, I learned something today. Thanks!
Last edited by Halakar at Jul 29, 2009,
#3
575 watts means it is converting 575 joules of energy every second.

Turning down the volume does not make the amp operate at lower power, it merely allows less of your signal to flow into the power amp, which is always running at around 575 watts.

575 watts is a lot for sound equipment, although a typical vacuum cleaner or kettle will use more.
#4
I believe it does consume less energy, but not by much of a difference. When you are turning down the volume, all you are doing is bleeding off some of the incoming signal.

Also, 575W is not really that much. If you are playing for two hours then you consume just over a kW of electricity, which is not really that expensive.
#5
so does a 50w amp consume the same power as a 50w light bulb?

I find that hard to believe.
Last edited by Tempoe at Jul 29, 2009,
#6
Quote by Tempoe
so does a 50w amp consume the same power as a 50w light bulb?

I find that hard to believe.


No it will use more energy than it sends to the speakers. The 50w rating is the power that it can send to the speaker. Its energy usage is probably something like 400W or so, it depends on how much current the amp needs to draw at 120 volts in order to supply all of the components in the amp with power.

EDIT:
I see what your saying though, TS is this 575W rating the power of the amp or the amount of power that it draws?
Last edited by XgamerGt04 at Jul 29, 2009,
#7
Quote by Tempoe
so does a 50w amp consume the same power as a 50w light bulb?

I find that hard to believe.


It's true. It's Ohm's Law, IIRC. P=IV or in this case it'd be I=P/V

sooooo, in America, V=120v, P=50w, so current'd equal whatever 120/50 is. It's about power output, really. Light bulbs are really inefficient anyway.

EDIT: F-word, I messed up. I just did the conversion for watts. So just take whatever I said and change it for watts.

So I=120v/50w
Last edited by Wrst_Plyr_Evr at Jul 29, 2009,
#8
Quote by Wrst_Plyr_Evr
It's true. It's Ohm's Law, IIRC. P=IV

sooooo, in America, V=120v, P=50w, so current'd equal whatever 120/50 is. It's about power output, really.


A 50W amp does not take as much power as a 50W light bulb, but its output power could be used to power a 50W light bulb if the output voltage was 120V.

My Peavey Delta Blues is 30W, but it uses 150W of electricity
#9
Quote by XgamerGt04
A 50W amp does not take as much power as a 50W light bulb, but its output power could be used to power a 50W light bulb if the output voltage was 120V.

My Peavey Delta Blues is 30W, but it uses 150W of electricity


It's summer. I don't remember a thing from Physics class, haha.
#10
TS your amp should consume about 700W of electricity per hour, if you look on the back near the IEC socket it should have something written under it about energy consumption.
#11
Quote by Wrst_Plyr_Evr
It's summer. I don't remember a thing from Physics class, haha.



+10
#12
Quote by Marshall46
I'll keep it short - If I have a 575w RMS rated amp (Ashdown ABM C115) running at low volume, does it consume less electricity than at full volume? If so, by roughly how much?


The simple answer is yes. Your pre-amplifier section will have a fairly consistent power draw, but the power-amplifier section will essentially draw the amount of power it needs to produce the notes at the correct volume. If you are playing at low volumes at home you are likely pumping out less than 25w.

The amount of input power you draw from the wall socket will be slightly higher than the amount of output power your amp is producing. Some of the electricity coming from the wall is converted into heat inside your amp. This is efficiency loss. For example, if your amp is 75% efficient it would need to draw 200w from the wall socket to produce a 150w output signal for the speaker (200 x 75% = 150). Bass amps tend to be more efficient at low power and less efficient at high power.

If you want to save on electricity play at low volumes. If you want to rock "crank that bitch".
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Laziest Bassist Alive
Keep your gig. I'm sleeping.
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#13
Quote by sashki
575 watts means it is converting 575 joules of energy every second.

Turning down the volume does not make the amp operate at lower power, it merely allows less of your signal to flow into the power amp, which is always running at around 575 watts.

575 watts is a lot for sound equipment, although a typical vacuum cleaner or kettle will use more.


I disagree; otherwise,where is the wasted energy going? if it's lost as heat, you'd feel the heat - the amp would be much hotter (physically) at lower volumes.

also, having less than the required power to an amp will cause it to go into overdrive sooner - Eddie van halen had a little box for limiting the power to his amp slightly to get more clipping, but I've noticed it with keyboards etc. too - as the batteries go flat, the sound will be OK at quiet volumes, but at loud vol. it will start to distort. my point is, if the Amp required 575w all the time, with any less power it wouldn't work atall.
#14
Thanks for the great response guys, this has been quite informative!

There seems to be a bit of a conflict though with regards to overall consumption, between...


Quote by sashki
575 watts means it is converting 575 joules of energy every second.

Turning down the volume does not make the amp operate at lower power, it merely allows less of your signal to flow into the power amp, which is always running at around 575 watts.

575 watts is a lot for sound equipment, although a typical vacuum cleaner or kettle will use more.



and...

Quote by LowEndSlacker
The simple answer is yes. Your pre-amplifier section will have a fairly consistent power draw, but the power-amplifier section will essentially draw the amount of power it needs to produce the notes at the correct volume. If you are playing at low volumes at home you are likely pumping out less than 25w.

The amount of input power you draw from the wall socket will be slightly higher than the amount of output power your amp is producing. Some of the electricity coming from the wall is converted into heat inside your amp. This is efficiency loss. For example, if your amp is 75% efficient it would need to draw 200w from the wall socket to produce a 150w output signal for the speaker (200 x 75% = 150). Bass amps tend to be more efficient at low power and less efficient at high power.

If you want to save on electricity play at low volumes. If you want to rock "crank that bitch".


Can anyone further enlighten us?

Cheers
#15
the basic question is, will i save money by playing at a lower volume? i say the difference is going to be so insignificant that you won't notice on your actual bill.
although the question brings up an interesting point, the only way to know, is to put a meter on your electrical outlet, and compare the electrical power drawn at different volume settings. if your worried about budgets, turn off your computer and practice your
bass. just my 2 cents. keep the change.
#16
No you will not save any money. When you turn the volume down, you lower the overall amount of energy that can be sent to the speaker. Your amp will still draw the 700W it needs to run, as this is what powers the components. You can run slightly over, or slightly under, but you will not make a change in this by changing the volume.

The volume controls do nothing other than bleed of signal. This has no effect upon how much power the components draw.
Last edited by XgamerGt04 at Jul 30, 2009,
#17
My amp runs at different voltages for different ohmages (i really need to learn some terminology), will this affect it's power consumption?

Ibanez SR506BM
Ashdown Little Giant 1000w
Peavey TVX 115+410
A big ass upright

#18
575 W RMS is the rate of energy provided to the speakers, as measured at speaker terminals, for continuous operation at full volume for hours on end. Your amp draws significantly more than that from the wall because before the juice gets turned into sound a lot of it is wasted as heat due to inefficiencies - I would eyeball the amp to use at least about 750W at full volume. When you turn down the volume, the amp will start consuming proportionally less energy just like a bugatti will burn less gas at 50 MPH instead of 250MPH even tough it has to turn the same pistons and power all the electronics.
#19
Quote by KingStill
575 W RMS is the rate of energy provided to the speakers, as measured at speaker terminals, for continuous operation at full volume for hours on end. Your amp draws significantly more than that from the wall because before the juice gets turned into sound a lot of it is wasted as heat due to inefficiencies - I would eyeball the amp to use at least about 750W at full volume. When you turn down the volume, the amp will start consuming proportionally less energy just like a bugatti will burn less gas at 50 MPH instead of 250MPH even tough it has to turn the same pistons and power all the electronics.

I like this man
#20
I can't believe the myths ad mis-information in this topic. Amazing!! For example, XgamerGt04 thinks the amp runs at full volume/power and only the input is bled off to reduce volume so it runs full power all the time. That would get quite hot at all volumes. No no no!! That is not how it works. So you have some faith in me I am an electronics engineer with many years of experience in a lot of areas, and I play guitar and have worked on quite a few amps [valves and transistors], PAs, keyboards and effects, etc.

The signal to the power amp section (from the pre-amp section) is varied by the volume control. The power amp puts out more power for a higher signal from the pre-amp and less for less signal. Depending on the power amp design there may be some bias current flow to minimise cross over distortion but that is a very small amount of power or the amp would burn out. So the power used is based on the volume setting, plus power used to run the pre-amp and the general circuit of the power amp.

So there is more power used for high volumes than low volumes. And more power is used than just the output rating but that varies from one design to the next and what fancy extras are added but its not a lot more.

Hope it all made sense.
#21
except those are all people who no longer actively use this area of the site, because that thread is about 3 years old.
#22
askrereExcept when you think about the fact that they most certainly received notice about him answering / replying...
Like you did... Right about... Now!
Nailed!! Bam!! ?
Last edited by adrianarmas at Nov 27, 2016,