Control volume with DAC or Preamp?

 its likely the loading is internal in the unit itself. 

And that we'll never know, as it is the graph shows roll off starting at 100hz already and that's with a 100k!!! loading, Stereophile usually also give a 600ohm loading,  strangely omitted this time.

Would be nice if someone that has one and can do the measurement, to see what happens with a 10k loading as many Class-D's have.
So to those going direct with this make sure your amps input impedance is >100k other wise as the bass "could" be anemic as  ozzy found out a few posts back.

Cheers George

   

Just for accuracy... The DS Dac is transformer coupled. You can see it here:

https://images.app.goo.gl/oDW85e3k2MKCXJP98

Same difference cap or trany coupled, they both will roll off the bass when used together by the input impedance of the next stage if not large enough as in this graph showing it’s bass roll off already starting at 100hz!!! and becomes more severe the lower the input impedance of the poweramp becomes, a 10k Class-D which many are would have zero bass output.
https://www.stereophile.com/images/914PSDSfig04.jpg

Cheers George

ozzy
I used to own the PS Audio Direct Stream Dac. Running direct to my amps it was a bit anemic.

That’s totally understandable when you see this frequency response graph, the roll off in the bass with a 100k load starts at 100hz and gets worse as it goes down to 20hz, which indicates to me it’s capacitor coupled.

And that capacitor "could" be too small (impedance mismatch) when it sees the input of what ever amp/s you have or even 10kohm Passive preamp load as well, it could be much worse and roll off the bass even more than with 100k, and resulting in your "anemic " sound

https://www.stereophile.com/images/914PSDSfig04.jpg

Cheers George

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  

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 

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

Quite often the volume control in a preamp is better than one in a DAC

This statement is false, it’s 50/50, and in case of a tube pre it’s more in favour of the solid state dac output stage

Both the dac and preamp volumes can be adjusted by remote control.

You achieve nothing doing this just preamp colouration and extra distortions, and extra interconnects,.
Your basically running a preamp into another preamp two volume controls and extra interconnects, it’s always best to use all the source has to offer when it has a digital volume, which your case has two high/low preset gain settings in the output stage.
Use it direct into the poweramp, on either the high or low preset that allows you to turn turn up the digital volume to the top of it’s range for loud listening.

By going direct with your setup you basically achieve what Nelson Pass says here, forget the reference to the passive pre, you have one stage better again than this if you go direct!!.

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

wolverine1 OP
My DAC (PS Audio Directstream) has a volume control and so does my preamp(Benchmark), of course. What’s the best way to control the volume of my system to get optimum sound

Best quality least distortion and coloration, and best dynamic swing, dac direct to poweramp using the dac as the volume control will be the best. Without any debate. As the PS audio’s dac output stage will as good if not better than the Benchmark preamp and has up to 3volts output at full, which is more than enough. You have 2 output max levels you can preset set, choose the one which gives you the highest volume level enough for the loudest you need to play.

BUT!!! if the dac "bit strips" on the lowest volume setting your using then there is debate. See where your volume is on the dac for normal listening then ask PS if it "bit strips" at that level, then your home and hosed, very simple thing to do.


I was just sent this PS Directstream volume control info, your PS DS does not bit strip with lower volume, so your good to go direct to poweramp/s for the very best SQ

The internal volume control keeps complete precision: every bit in the input affects the output of the DAC for any volume level. Except for the sigma-delta modulation process itself there is no rounding, dither or other trimming, not to 24 bits, not to 32 bits, not to 48 bits, but rather a full 50. The incoming PCM signal is 30 bits from the upsampling fi lter and the volume control is 20 bits wide so all 50 bits of the output are used throughout the sigma-delta conversion, requiring more than 50 bits of precision.

Cheers George