Are Preamplifier’s Relevant Today or just a Hinderance with Digital Playback ?

Totally system dependent.  I don't recommend digital volume contrl. It will cut fidelity in most cases.  DAC output vs volts needed for full output from your amp help you decide.  Speaker sensitivity also comes into play.  Some systems need gain from preamps some don't.  Active preamps will change the sound.  Its up to you whether it is better or worse.  

One way or another, a system needs volume control and source-switching (assuming it has more than one source). If you have only one source, and it's digital, you could get away with software volume control only. In my limited experience with it, software volume control seems to compromise SQ compared to a good hardware implementation.  

At any rate, in between a computer that runs DSP (like HQ Player) and a power amp, there generally needs to be a box with USB/other input (at least) and loudspeaker outputs. How is it a hindrance if that box supports source switching, volume control, IR remote, etc.?  Unless you just want to connect powered speakers (or headphones) directly to the computer.  But then you need a keyboard, display, mouse/trackpad to control the computer (instead of connecting a "headless" computer to a component audio system).  Seems like more of a hindrance than a preamp.

does not matter if you use analogue or digital front end. You need a preamp with enough current output to handle the dynamic swings. But don't listen to me or anyone else. Try it yourself, go without a preamp and run DAC directly into power amp (assuming you can control output level at some  pt).
you will find dynamics are compressed, bass is not as good, and sound stage suffers.

The long and the short you can then use passive attenuation which is represented by resistance, vs adding via active preamps which can't help themselves but add various flavors of reactance, in so doing distancing you from what is possible.

The issue here is cables; with a passive system the cables are uncontrolled and can cause colorations. If the preamp is able to control the effects of the cable (and if it supports AES48 which is the balanced line standard it can) then its very possible to find that a preamp is more neutral than the best passive available. Most digital systems just don't have a good ability to control the interconnect cables (if you drive 30 feet of cable you'll see what I'm talking about) and if you put a passive between the digital source and the power amps you'll exacerbate this issue.


I've yet to encounter a passive system as transparent as a good preamp.