Benchmark LA4 Preamp?

I've read numerous reviews in forums, etc that The HPA4 is quiet as a mouse and gets out of the way

With that silence you hear music that was obscured before.

The other night I wanted celebrate a big win by one of my sports teams. So I cranked up 2112 by RUSH because it was a Toronto team that won.

I am listening on headphones via the HPA4, my Meze Empy phones are not even supposed to be detail kings like the Focal Utopia, I start hearing echo in one track that never heard before and I knew this track for 40 years. This echo, purposefully added by the musicians, added a nice quality to the song. I am like where the heck did that echo come from. You feel like you are hearing all the music with this gear and I get so immersed into the music.

I'm using the HPA4 as preamp driving my active ATC SCM100 towers.
The best way to think of this pre is as a direct conduit that allows source selection and volume control.
This makes it the theoretical ideal preamp, but I think it's clear that not everyone wants this sort of truthfulness to source.
If you're looking for something to warm up or otherwise embellish/emphasise your sound in any way, then look elsewhere.  
I think the HPA4 is a great piece of equipment - especially when you consider that other companies that pursue this perfectionist ultra low distortion/noise approach charge far more. 

I have been using the LA-4 Line Amplifier since early this year. Simply put, it is "the sound of silence." I have a rather simple, but not an inexpensive system.

System: Aurender W20SE, Vivaldi DAC, Vivaldi Word Clock, Pass Labs XA-160 mono block amplifiers (soon to be replace with the MBL 9008A mono block amplifiers), MBL 101E MkII speakers and Tripoint NG ground system. Acoustic Zen Absolute Silver balanced interconnects and Absolute Silver speaker cables (dual pair bi-wiring for each channel). Audioquest Wild Digital balanced interconnects (dual-wire configuration). Shunyata Research Sigma word clock cables and Alpha power cords. Shunyata Research power conditioning for source components. Six dedicated 20 amp outlets.

When I purchase the dCs Vivaldi units, I was using the Pass Labs XP-30 preamplifier. When the XP-30 was compared to the Vivaldi digital volume control, I could clearly hear a slight haze (veiling) to music when played through the XP-30. So, out went the XP-30 to a new home and for a while I only used the Vivaldi volume control. However, I am not so much a fan of digital volume controls, and for bit was searching around for a preamplifier. Having a simple system, I really had no need for preamplifiers with numerous input/output options. What I really wanted was a simple, linear preamplifier with a killer volume control.

It was following a Stereophile review on the LA-4 that got me thinking this line amplifier might be worth pursuing (a 30 day money back guarantee from Benchmark made this an easy experiment). Well, I was not prepared for the purity and lack of editorialization on sound through the LA-4. There is lot invested in my front end and down stream. The LA-4 simply gets out of the way. It is the closest to a straight wire with gain I have heard.

The downside of the LA-4: I is ruthless revealing and some may find rather sterile. There are no added colorations (least that I can appreciate), so if recordings are poor, they will sound poor. It will also lay bare the capabilities of components up stream.

The LA-4 has done nothing to the alter the performance of the Vivaldi/Aurender front end combination. The "sound of silence" and very highly recommended. 

@nedkuehn You did what I am hoping to do with the HPA4. I was going to get the Mola Mola Makua at close to $20K but I kept reading that the LA4 is like a $20K preamp and also silent like the Makua. So I tried the HPA4 and I came to the same conclusion you did. I took it one step further by buying the AHB2 amp a few weeks ago and hope to get delivery next week. The plan was to get a Luxman m900u or Coda #16 to flavor the sound, but since the HPA4 was so good I wanted to give the AHB2 a try for 1/5th the cost. Even if I want that additional flavor with the amps I have a second system where the AHB2 can be used.

There are a few folks on Whats Best Forum having both a $20K preamps and the LA4, that are stating the same observations as you. They also have very expensive sources components and amps.