Musical Fidelity X-10 Tube Buffer Stage

install the device on a tape-loop of your SP11 pre. This way you won't have to suffer the additional degradation of that extra interconnect cable-pair when the X-10 is switched out, &/or you can buffer additional source equipment as desired. Bear in mind that the extra cables inline with your signal are a significant limiting factor; quality & synergy are both very important factors.

Hi CW yes you have correctly understood my suggestion; however you also correctly point out that the signal would be inline with yet another interconnect cable pair, only 'when the buffer is inline'. This may not be the best configuration - if you typically have the buffer inline *most* of the time then you'd probably be better off not using the tape loop. But again yes, the switching arrangement does then allow for easy A/B comparisons.

I don't really have an opinion re "which is better" the only answer to the question lies in experimentation. Cable quality & synergy are certainly limiting factors; try it both ways if possible.

There may be some other ways to 'tame the SCD-1's high end' have you experimented with:
(1) the interconnect pair
(2) the AC cable (on the player & on the pre & PA)
(3) tweaks such as shelving, cones, footers...
(4) AC line conditioning