Best Line Stage Preamp?

The Placette Active is actually a "no gain" preamp.
The two output amplifiers only lower the output impedance to a very low level to improve accuracy of the signal transfer.

If you are interested in a very transparent, active linestage, you might consider the First Sound Presence Deluxe Mk II Linestage. Despite having a high degree of transparence, it has excellent dynamics. I have this linestage as well as a CAT Ultimate preamp and I would say that the First Sound will give a more immediate, more present rendering of the music. The CAT is more weighty in the low mids and low bass, has stunning dynamics, has a beautiful harmonic structure, but is a bit more bloomy in the mids and just a bit more diffuse in the mids. The F.S. is stark by comparison. It is the ultimate in clarity, quietness and delivery of a black background from an active unit. Rock-solid, very stable imaging and very wide soundstaging on the F.S. Female vocals can be outstanding with this unit, depending on the recording. I like both the CAT and F.S. for different reasons, but if you are biased to hear midrange accuracy, clarity and transparence over midrange sweetness and musicality, I would say that the F.S. is worth an audition, particularly since it also has considerable dynamics.

The F.S. has a relatively high output impedance of about 1700 ohms which could be a problem with certain low impedance solid state amps, such as Pass amps. This might cause a loss of dynamics and some low-bass rolloff when the F.S. is matched with such an amp. I doubt that would be a problem with your tubed KR Antares.

I don't know about "best", as that is purely subjective based on personal preferences, system synergy, etc...

My personal "best" is also the First Sound Presence Deluxe mkII. It outperfomed 5 other good preamps that I've had in my system over the last year or so.

Actually, there probably is a 'best'. A line stage should perform the following functions:

1) control the effects of the interconnect cables in the system. In general, transistor units do this rather well and tube units do this rather poorly, passive units do it the worst.

2) provide a proper volume control system. This means that the position of the volume control should have no impact on the quality of the sound (a big problem with passive setups and digital volume control systems, a very noticable issue with the vast majority of remote volume control systems).

3) Gain is helpful, but not manditory- a lot depending on the amplifier being used and the efficiency of the loudspeakers being used. Generally moderate and lower efficiency speakers (92db or less) will have some benefit from a little gain in the line section, unless the amplifier has a very sensitive input. If the unit does have gain, that gain must be wide bandwidth (+100KHz) and low distortion.

4) provide an input signal switching capability. This again is not mandatory, for those who only have one source. However input switching can greatly add to ease of use (and if the stereo is hard to use, it will gradually get listened to less often). If input switcing is present, it should be sonically transparent.

Given thes things, ultimately the goal of reproduced music is to sound identical- indistinguishable- from the real thing. To this end the line stage is critical, and this is not about taste, it is about accuracy. Most transistor units tend to impart a stilted quality that is instantly recognizable to the trained ear. This raises the bar on transistor units, leaving tubes to be the main contendors. The possible exception might be a buffered unit with an extremely high quality volume control, but the higher resolution systems usually have no trouble revealing even the relatively transparent buffer circuitry.

I have found that it is unwise to set up a system around equipment that has symbiotic synergies. If this is done, it becomes very difficult to upgrade, plus there is the issue that the synergy is almost always hiding something, including detail in the music.

Choose, and choose wisely.

The Messenger preamp and the Meitner Switchman 3.