Control volume with DAC or Preamp?

Unless there’s some problem, the lowest noise is always achieved if you use all or most of what the source has to offer.
If not your throwing away source signal to ground (earth) with the active preamps volume pot just so the "gain stage" (that not needed) of that active preamp can make it back up again!!!!!

Nelson Pass tells everyone that here, why is it so hard for many to understand, (mental blocks perhaps).

Nelson Pass,

“We’ve got lots of gain in our electronics. More gain than some of us need or want. At least 10 db more.

Think of it this way: If you are running your volume control down around 9 o’clock, you are actually throwing away signal level so that a subsequent gain stage can make it back up.

Routinely DIYers opt to make themselves a “passive preamp” - just an input selector and a volume control.

What could be better? Hardly any noise or distortion added by these simple passive parts. No feedback, no worrying about what type of capacitors – just musical perfection.

And yet there are guys out there who don’t care for the result. “It sucks the life out of the music”, is a commonly heard refrain (really - I’m being serious here!). Maybe they are reacting psychologically to the need to turn the volume control up compared to an active preamp.”

Cheers George

@georgehifi I respect your perspective, but you can't tell people their ears are wrong when they find that an active preamp improves system performance. 

The nice thing about having volume control in both pre and dac is that it allows you to find out for yourself. When I did that I found that the pre-amp improved system performance in every way. Bascom King and many others have found the same. Some others like you have not. As always, you have to try it in your system to know which will hold for you.

The nice thing about having volume control in both pre and dac is that it allows you to find out for yourself.

What you have is basically two preamps running in series into each other, who does wants to do this craziness. 🥴

When I did that I found that the pre-amp improved system performance in every way.

What you found is you preferred the coloration/distortion that way, that the extra preamp gave you. (you need to fix the sound of your source because you don’t like it)
Next you’ll say 3 or 4 preamps in series it sounds better 🤦‍♂️🤦‍♂️🤦‍♂️or🤦‍♂️

Bascom King and many others have found the same.

Of course they do, they sell preamps 

George is omitting the rest of Nelson's comments when he makes that quote. He seems to do this as part of his 'product protection' program, since he sells (actually a very good, but also obviously not of his own design) passive volume control. Here is the rest of that passage, starting at exactly the point that George stopped:

I suppose if I had to floor the accelerator to drive 55 mph, maybe I’d think the life was being sucked out of my driving. Then again, maybe I like 55. Nice and safe, good gas mileage…

Is impedance matching an issue? Passive volume controls do have to make a trade-off between input impedance and output impedance. If the input impedance is high, making the input to the volume control easy for the source to drive, then the output impedance is also high, possibly creating difficulty with the input impedance of the power amplifier. And vice versa: If your amplifier prefers low source impedance, then your signal source might have to look at low impedance in the volume control.

This suggests the possibility of using a high quality buffer in conjunction with a volume control. A buffer is still an active circuit using tubes or transistors, but it has no voltage gain – it only interposes itself to make a low impedance into a high impedance, or vice versa.

If you put a buffer in front of a volume control, the control’s low impedance looks like high impedance. If you put a buffer after a volume control, it makes the output impedance much lower. You can put buffers before and after a volume control if you want.

Ralph is product (his active preamp) protection mode, omitting the reason behind a "why" the "rare" times a passive "may not" be the least coloured, least distorted, and best dynamically

Only when there is a impedance mismatch which is maybe 5% of the time, when the ratio is lower than 1:10
 
As most sources can easily drive a 10k passive, and a 10k passive can easily drive power amps that are 33k or higher input impedance, most are, the industry standard 47k and most tubes are 100k.
Only some silly Class-D are 10k input, passives don't suit these, as to many tube pre's don't either

Cheers George