Preamps waste of money?

I too like preamps and find that they can provide an optimal source impedance and gain stage that enhances the sonic performance. Passive is not always "better."

My experience with preamps is that at a certain price point an active preamp can get you the level of detail that a passive provides. In my experience, a passive preamp while giving gobs of details also tends to limit dynamics and drive. The "oomph" as you will. This will be more or less important according to both your music preferences and what matters most to you for musical reproduction. At lower price points this trade-off between detail and drive is a decision that each of us must make for ourselves.

And it must also be noted that passives and attenuators will not work well in a number of situations, particularly when a source has a high output impedance and an amp has a low input impedance.

Others more knowledgeable than myself will likely chime in to add to this.

In my system a good active preamp has made a world of difference. Does the preamp color the sound. Yep. However, the older I get the less I'm concerned about such issues as long as my ears are happy. I've gone the passive route but never found them as beneficial. Whatever works for you.

If your source and amp are a good match, a passive attenuator will work great. If not, a preamp is the correct way to go.
I have a Lightspeed attenuator in my system and love it.

Preamp has many functions other than volume control
- input selector
- balance control (some have tone control)
- impedance matching
- allows use of balanced cables
- breaks ground loops on balanced connections (transformers)
- absolute phase inversion
- some allow to adjust level for each input (Rowland Chorus)
- have unity gain bypass for the theater system
- phono amp for TT
- rumble high pass filter
- remote control
etc.

If you don't need any of it then any stand alone volume control will do. I use Benchmark DAC1 as a preamp with volume control for 3 digital sources with balanced cables to power amp.