# How does a receiver's volume setting correlate with the output?



## twilyth (Dec 11, 2011)

Both of my receivers display output (volume) in db.  My RX-V765 has 95W into 7 channels.  If the display says my output is -10db, how many watts is is it putting out?  Does the display mean anything at all?  Thanks.


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## qubit (Dec 11, 2011)

It all depends on how it's calibrated and the strength of the input signal.


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## twilyth (Dec 11, 2011)

Regarding the strength of the inputs, let's say they are all digital, which in my case they are.


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## 1freedude (Dec 11, 2011)

I'm gonna guess that is it is simply a logrithmic scale to indicate knob position.

Does the knob have stops at -infinity db and 0db?


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## twilyth (Dec 11, 2011)

1freedude said:


> I'm gonna guess that is it is simply a logrithmic scale to indicate knob position.
> 
> Does the knob have stops at -infinity db and 0db?



I don't know abouty -∞ but it does go at least to -50db and +10db.  Never tried to push it farther in either direction.


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## 1freedude (Dec 11, 2011)

What I mean is....does the knob just spin and spin and spin?


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## qubit (Dec 11, 2011)

twilyth said:


> Regarding the strength of the inputs, let's say they are all digital, which in my case they are.



No, when I said the "strength" of the signal, I meant the amplitude of the analog sound's waveform. The fact it's transmitted digitally isn't relevant.


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## twilyth (Dec 11, 2011)

I don't understand.  Since it's digital, the amplitude would have to be encoded.  AFAIK, you can only attenuate that from line level.


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## 1freedude (Dec 11, 2011)

Think pwm


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## twilyth (Dec 11, 2011)

I don't think they use pulse width modulation for audio.  Do they?


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## 1freedude (Dec 11, 2011)

http://www.netrino.com/Embedded-Systems/How-To/PWM-Pulse-Width-Modulation


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## twilyth (Dec 11, 2011)

I'll try again later.  It's saying I can't load the page. {shrug}

edit: server not found.


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## 1freedude (Dec 11, 2011)

It says pwm is used to digitally encode analog


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## BumbleBee (Dec 11, 2011)

twilyth said:


> Both of my receivers display output (volume) in db.  My RX-V765 has 95W into 7 channels.  If the display says my output is -10db, how many watts is is it putting out?  Does the display mean anything at all?  Thanks.



there is no way to tell. if you plug in a kill-a-watt meter the readings are going to be all over the place.


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## Jetster (Dec 11, 2011)

My Yamaha XR V571 show output in a way that I do not understand at all


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## Bundy (Dec 11, 2011)

I don't know a lot about this but AFAIK, 0dB is the reference volume. If everything is set correctly, and when playing the reference pink noise, your amp will be at maximum wattage and the speakers will be pumping the reference volume (e.g. Dolby is 105dB) when the volume is at 0dB.

As this is almightly loud, most systems use -20dB as the reference point for calibrating speakers.


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## de.das.dude (Dec 11, 2011)

amplifiers. you cant explain that.


i think a sound engineer will be able to tell you the real answer.


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## qubit (Dec 11, 2011)

twilyth said:


> I don't understand.  Since it's digital, the amplitude would have to be encoded.  AFAIK, you can only attenuate that from line level.



I think this really calls for a diagram, but unfortunately, I don't have one, lol.

Ok, let's put it another way. If the singer sings softly into the microphone, the volume level is quieter than if they shout - there's a huge difference, in fact. The output of the amplifier follows this, therefore the wattage being put out at any instant varies dynamically with the input signal - and that variation can be huge.

*EDIT: the difference in amplitude between the input signal and the output signal is called the gain of the amplifier. Adjusting that volume knob alters this gain. Therefore, the actual output level - watts put out - with the volume knob at any particular point depends on the input signal and the volume knob.*

As you can see, the above explanation doesn't say anything about how the signal is transmitted to the amplifier. Regardless of whether it's done in the analog domain or the digital domain, the result is the same. In the digital domain, the bigger the numbers, the higher the volume.


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## Frederik S (Dec 11, 2011)

It is the attenuation level which the amplifier applies. It is not the dB of the speakers.

-0 dB means that the amplifier is at full gain. It is related to how many watts it is putting out, but in order to compute that you need to know the speaker load, which is variable across the frequency spectrum. Your amplifier will at - 0 dB be able to output 95W RMS into a 8 Ohm load. 

A digital-in will be converted by the DAC in the amplifier Usually the DAC will output something that is very close to a normal line-level signal which is then routed to the gain stages in the amplifier.


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## twilyth (Dec 11, 2011)

Thanks man.  that's exactly the assumption I had been going on but I didn't have anything to base it on.  Much appreciated.


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## BurgKaW97521 (Dec 12, 2011)

Thanks men for all your tips


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## AsRock (Dec 12, 2011)

Jetster said:


> My Yamaha XR V571 show output in a way that I do not understand at all



Same here i turn the crap off lol.


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## CJCerny (Dec 12, 2011)

twilyth said:


> Both of my receivers display output (volume) in db.  My RX-V765 has 95W into 7 channels.  If the display says my output is -10db, how many watts is is it putting out?  Does the display mean anything at all?  Thanks.



There's no way to tell how many watts are being output by the receiver based on the db display. The watts output is different at -10db based on the impedance of the speakers you have connected to the receiver.


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