Are Pre-Amps necessary?

George, not sure where your list of "all those preamps" came from but of those, the Khozmo (i.e., Hattor) is the only one I have owned.  I do own McCormack's TLC-1 passive/buffered stage that Steve has upgraded to a much higher level that he calls  "very close to my VRE-1."  When I owned that Metrum Adagio DAC with internal VC, I modified the TLC by taking the Shallco VC switch out of the circuit (replaced it by soldering two AN Tantalum silver resistors to the board) thus turning it into a unity gain buffer w/o VC.  I did that because, to me, the Metrum DAC sounded noticeably better with the active buffer in the chain, even though the DAC output 4V.
I have since moved to Mojo Audio's EVO B4B 21 DAC, which does not have a VC so I added the passive Khozmo unit, which provides remote VC, balance control, and a nice visual display.  I have tried running my system with just the Khozmo passive unit but I much prefer the sound with the TLC active buffer also in the playback chain. 

That list came from a post you made a while back.
You don’t use a Metrum Acoustics Adagio dac now?

Also understandable that you preferred the active buffer as the Khozmo, and most tube pre’s would not have suited the 10kohm input impedance of the SMc monos.

Cheers George

"Since it is equipped with high-class preamp, this player may also double as the heart of a small, but very fine high-end system."

Odd that Burmester 089 should have been great direct, as recommended by the manufacturer. As it’s output is a 60 position VC active preamp with a switchable tape input also, as these spec show with 4v low output impedance you defiantly don’t need to run a preamp into another preamp with even more gain from the second preamp. Their must be another reason, preferred additional preamp, coloration perhaps
https://www.i-fidelity.net/en/test-reports/high-end/burmester-089/labreport.html
Output voltage: 4.1 V
Channel deviation: 0.035 dB
Output resistance: 256 Ω
DC output offset: < 0.5 mV

Cheers George

George, you may look at the description of Burmester 001 player, I believe you will read similar text as of 089.

In review in Stereophile (if that mattters) the reviewer concluded, that no matter how good the player sounded connected directly, it sounds better (for him, at least) with its preamp (011).
 Is the difference worth 16t usd (in Us, in that time) everyone should decide for himself.
I had both pieces, together with 956 mk2 amp.
Same thing with 089. Its just sounds better with Burmester preamp

I respect your technical knowlegde, but reading some of your posts I have noticed that you have few 'fixations' (in lack of better word, as english is not mine mother language)

I can understand that somebody likes one type of sound better than the other, but neither point of view should be dogmatic.

Your personal feeling when you listen without preamp, or with passive preamp is just that, a personal perspective.

For example,many times I have read your preference toward R2R dacs, but imho the Burmester 089 sound better, with 1794 BB (which is hybrid,as I understand) than the Burmester 001 whuch has 1704 BB, R2R configuration.

Just wanted to say that one should try to have open mind (and ears) and not make conclusions based on what 'should' sound better,instead of listening first.
Hope that these few words do not sound as a 'lecture', as that was not my intention, but just as reminder how unpredictable this hobby might be
 

Your personal feeling when you listen without preamp, or with passive preamp is just that, a personal perspective.

Sorry not just personal (subjective), but technical (objective) just as much if not more so.

Cheers George