Soldato
- Joined
- 6 Sep 2016
- Posts
- 11,424
My audiolab 8000q has gain switch. What is reason to change it beteen 0,3,6,9,12 and 15?
I'm using matching 8000px amps.
I'm using matching 8000px amps.
pre amp gain control
- Thread starter hornetstinger
- Start date
It's a Tare function. The manual gives some hints and talks about starting with 9dB Gain, then either adjusting down if the speakers are very sensitive or you listen a lot at low volumes (or the source components output a high voltage signal), or adjusting the gain up if the speakers aren't that sensitive or the source components have low output voltages.
In broad terms, active analogue volume controls in pre-amps and integrateds will have some inherent noise. When the volume control is set low, this background noise represents a large proportion of the signal going to the power amps and speakers. Using a higher volume setting reduces the impact of the noise, but that might mean the sound from the speakers is too loud; so how do you get to use more of the volume control's range without blasting out the neighbours?.... The answer is an adjustable Gain control.
To give you a better idea, we'll use some numbers just for illustration purposes.
Let's say your amp volume control goes from 0 to 100. Let's also say that the inherent noise has a value of 1. We'll pretend that you like to listen at low volumes, and you've got pretty sensitive speakers and the source gives a very healthy signal level. All this combined means that your preferred listening volume is achieved with the volume dial at 10. If the background noise is 1, then 1/10th of your sound going to the speakers is noise (10%).
Now let's pretend that the next lower Gain setting means that your comfortable listening level is achieved at 30 on the dial. This time, only 1/30th of the sound is background noise (3.3%). Take it to the next lower Gain setting (the lowest) means your volume control is set at 60. Now just 1/60th of the sound is background noise (1.6%). In reality the percentages would be a lot smaller, but the principle remains the same; it's minimising the percentage error.
Going the other way - insensitive speakers and/or low output sources combined with the desire to listen at higher volumes might mean that the volume control is up near maximum before you get the sound level you need. There's an argument to say that active volume controls add high frequency distortion as they approach the upper end of their adjustment range. If that's the case, then by changing the sensitivity you could hit your desired listening level with the control somewhere around the 2/3rds to 3/4 position.
In broad terms, active analogue volume controls in pre-amps and integrateds will have some inherent noise. When the volume control is set low, this background noise represents a large proportion of the signal going to the power amps and speakers. Using a higher volume setting reduces the impact of the noise, but that might mean the sound from the speakers is too loud; so how do you get to use more of the volume control's range without blasting out the neighbours?.... The answer is an adjustable Gain control.
To give you a better idea, we'll use some numbers just for illustration purposes.
Let's say your amp volume control goes from 0 to 100. Let's also say that the inherent noise has a value of 1. We'll pretend that you like to listen at low volumes, and you've got pretty sensitive speakers and the source gives a very healthy signal level. All this combined means that your preferred listening volume is achieved with the volume dial at 10. If the background noise is 1, then 1/10th of your sound going to the speakers is noise (10%).
Now let's pretend that the next lower Gain setting means that your comfortable listening level is achieved at 30 on the dial. This time, only 1/30th of the sound is background noise (3.3%). Take it to the next lower Gain setting (the lowest) means your volume control is set at 60. Now just 1/60th of the sound is background noise (1.6%). In reality the percentages would be a lot smaller, but the principle remains the same; it's minimising the percentage error.
Going the other way - insensitive speakers and/or low output sources combined with the desire to listen at higher volumes might mean that the volume control is up near maximum before you get the sound level you need. There's an argument to say that active volume controls add high frequency distortion as they approach the upper end of their adjustment range. If that's the case, then by changing the sensitivity you could hit your desired listening level with the control somewhere around the 2/3rds to 3/4 position.
- Joined
- 6 Sep 2016
- Posts
- 11,424
Yeah ta thought it's like that you want volume control pot to be in certain range, if it's loud within the first 1/12th the pot doesn't track accurately.
Remember having a nad Poweramp and that had a low/high gain setting on the Poweramp input, so different it's on the input not at the pre amp stage. So you can tailer it depending on what pre amp you have, as some are 1v at 100% others 1.5v or higher maybe upto 6v
Remember having a nad Poweramp and that had a low/high gain setting on the Poweramp input, so different it's on the input not at the pre amp stage. So you can tailer it depending on what pre amp you have, as some are 1v at 100% others 1.5v or higher maybe upto 6v