Amplifiers on the market are usually loud at the 9 o'clock position. At that position, the slightest turn of the knob causes a large amount of change, making the adjustment clitical, and also increasing the gang error.
I prefer to use the amp at about 12 o'clock, so I determine the gain of the amp after the volume pot accordingly.
Specifically, I set the preamp gain to 0 dB.
In other words, the impedance raised by the volume pot is reduced by a 0dB buffer with low common-mode input distortion to lower the output impedance and output the signal to the power amplifier.
The output of the DAC is 2Vrms (at 0dBFS)
Attenuation at 12 o'clock position on the volume pot is 1/7 (-17dB)
Power amp gain approx. 22x (+27dB)
So the maximum output of the power amp is 5Wrms (8Ω).
My power amp is 40W, so if I turn the knob up to the 3 o'clock position, the signal clips at 0dBFS.
I think it is best to discard the extra gain after the volume pot for better S/N.
I prefer to use the amp at about 12 o'clock, so I determine the gain of the amp after the volume pot accordingly.
Specifically, I set the preamp gain to 0 dB.
In other words, the impedance raised by the volume pot is reduced by a 0dB buffer with low common-mode input distortion to lower the output impedance and output the signal to the power amplifier.
The output of the DAC is 2Vrms (at 0dBFS)
Attenuation at 12 o'clock position on the volume pot is 1/7 (-17dB)
Power amp gain approx. 22x (+27dB)
So the maximum output of the power amp is 5Wrms (8Ω).
My power amp is 40W, so if I turn the knob up to the 3 o'clock position, the signal clips at 0dBFS.
I think it is best to discard the extra gain after the volume pot for better S/N.
Your scale is confusing. The pot rotation is linear but the attenuation of the volume control is logarithmic. 2 o'clock tends to be the -6 dB point (50 %). 7-8 o'clock is probably -80 dB on most systems, so 0.01 %.
My volume control usually sits in the -40s dB. That's with 20 dB gain in the power amp.
Tom
My volume control usually sits in the -40s dB. That's with 20 dB gain in the power amp.
Tom
I polled position since it is easy to figure out. 🙂
This article has a graph of resistance versus position.
My volume control sits in the -30s dB. The amplifier has 32dB of gain.
Ed
This article has a graph of resistance versus position.
My volume control sits in the -30s dB. The amplifier has 32dB of gain.
Ed
The OP assumes that the control resembles a clock which is not always the case.
For example, many professional audio processors show a scale of 1 to 10 for example:
For example, many professional audio processors show a scale of 1 to 10 for example:
techtool - Yes, but I wanted an easy poll.
newvirus2008 - The poll choices work with a scale of 1-10.
Ed
newvirus2008 - The poll choices work with a scale of 1-10.
Ed
Mine is an encoder wheel that spins as much as you’d like. I would guess 9-10 o’clock though. But it depends on the material and what I am doing at the time…. and whether or not my lovely wife is around.
The smartphone SPL meter apps are quite good.
A few years ago I compared some apps to a calibrated SPL meter and they were within a dB.
The ‘70’s receiver that was gifted to me was at about -50dB at 8’oclock, and by 11 it reached very high levels. Past 1 o’clock the change was progressively smaller. When it was built, most audio sources were -10dB (ref.1V), ie 0.316V. Respectively, that’s 16dB lower than modern 2V sources, so there was a lot of unused gain.
My new preamp is unity for the time being with a 30dB gain amp.
My new preamp is unity for the time being with a 30dB gain amp.
Sorry, but the poll choices seem to be 1-12 and as rightly pointed out above by tomchr, the gain is logarithmic, which makes dial position a not very well-defined thing. Again, this is just the control, the amplifier power and loudspeaker SPLs are differ which is also a problem.
Personally, I prefer at least 3dB of headroom, that would put the max gain at -3dBFS or 7.0/10.
The changing standards are a problem. I use 0.775V (derived from 1mW into 600 ohms).
newvirus2008 - The poll has 10 choices.
Ed
I don’t see it that way, IME it’s the equipment. I agree with @mason_f8 above.
I once had a Pioneer amp that was way too sensitive at the inputs. Get it up to 9:00 and it was screaming. A semi useless volume control on an otherwise good piece of gear.