Best Preamp - NO preamp... (?)

I think i always worried the direct-to-amp would be too raw and "un-prepped."

Sorry electroslacker forgive me.

Raw?? Unprepped?? This is something the voodoo'ist have instilled into you.

The source, is the start in a system and it's signal should go via the purest path to the speakers, anything in-between that changes it, is not pure and just adding distortion and or colourations.
 
As for your impedance match, you couldn't ask for anything better, low impedance solid state output of the Benchmark, into the high input impedance of a tube amp, as perfect as an impedance match gets.

Cheers George

Thanks, George. You’re forgiven, and I think I’m healed for now.   What were those three temptations? Miracle, bread, and power….sounds like a devilish AR Ref 6 (lots of my bread.) Get thee behind me…but geez, it must be wonderful. One day at a time.

Yes... the AR Ref preamps look like they're among the very best available.  I've got the Ref 3 and Ref 5se... and... they are incredible - though, as I noted above, I am surprised at how good the Creek Passive Preamp sounds in comparison for a pittance in price.  

I did note in Collums ratings of preamps in HIFI Critic that he rated the AR Ref 5se at 225, compared to the highest rated Townshend Allegri at 230 (an autotransformer passive preamp).

Presumably, the AR Ref 6 and Ref 40, would be somewhat better - as most who have had both the 5se and either of the others report - though, at significant price premiums to the 5se, and of course, to the Allegri.  

At $2300 the Allegri looks like a "real bargain"... if... you can live without the conveniences of switching, balanced connections, and the remote.  Though, those conveniences come at very hefty premiums.  

And... I guess you could consider the AR Ref 3 as almost as grand a bargain at it's current price in the used market.  Most who have had both the Ref 3 and Ref 5 - 40 report that the Ref 3 is by far the "sweet spot" of the AR line.  So... perhaps... the price premium for those conveniences and great sound of the AR units is only about 2x the price of the Allegri.

Though you still have the cost of maintaining the AR tubed preamps - which the Allegri avoids.

  

I'm currently auditioning the new Benchmark HPA4 preamp/linestage/headphone amp and my DAC2 HGC against a Dangerous Audio Convert 2 Pro DAC.  I'm very sad to say the HPA4 Preamp does rob me of some upper frequency sparkle and transient response.  I've run through putting the hpa4 in and taking it out several times and running each DAC direct to either my Nord Monoblocks or my Art Audio Diavolo SET Tube 300b Amplifier to my Tekton Design Encores speakers and regardless of the DAC or amps I'm using I can hear clearly a noticeable drop in resolution, upper midrange clarity, and transient response. Plucks of guitars seem a little lifeless now. The overall sound is more homogeneous sounding and more 2 dimensional sounding.  It's a warmer less neutral sound, but almost like a film coating painted on everything I hear.  This is really disappointing because this preamp was supposed to take my system to the next level, but unfortunately it's a step backwards for me. I'm returning it to Benchmark, but I really feel bad about it all the same. 

As an aside I love the Benchmark DAC2 HGC, and will be upgrading to the DAC3 HGC.  For what its worth the Dangerous convert 2 dac I was auditioning sounded well nigh identical to the Benchmark once the gain level was matched, but it lacks the remote, multiple outputs, and because I'm returning the preamp won't work in my system. It's definitely a competent piece and those level meters provide some sexy eye candy that I will miss over the boring utilitarian looks of the Benchmark DAC2 HGC.