Audio Research LS 25 MkII compared to actual AR production ?

Hi all and thanls for your forst suggestion.

Today I tried a Shunyata Black Mamba HC on the LS25. Difference between Furutech FP-3TS20 and Shunyata is great, but I'm puzzled about the bass that became maybe too dry (remember with spectral and wilson I *need* body ;-) ). Tomorrow I will continue my listening session.
Shunyata effort on sound is, generally speaking, invasive, and its contribution has to be evaluated carefully, IMHO (I love Shunyata but I'm conscious they are not cables for novices) .

Ref 5se. Good suggestion , thanks @lostbears
Ref3, thaks @mitch4t  and @adg101, my only concern it's -more or less- a preamp with the same age of L25, I'm not sure I want to buy an old equipment more.

Maz
 These folks all mean well but
  your amp is 10 K input impedance.
This is what you are really up against.
 Best,
   JohnnyR
 

Johnny is right, as usual.  Just about every ARC line stage and preamp for which I've seen specs, including the LS25 MkII and the other ARC models that have been mentioned, has a **minimum** load recommendation of 20K, and the input impedance of your Spectral amp is 10K.  Although in both cases it isn't made clear if those numbers apply to the balanced or unbalanced interfaces or both.

In the case of a tube preamp a significant consequence of that sort of mismatch is likely to be perceptible rolloff of the bottom one or two octaves.  That will occur because of the output impedance rise at deep bass frequencies that will be caused by the coupling capacitor that is used at the output of most tube preamps.

Good luck.  Regards,
-- Al
 

Yes @audioconnection and @almarg , I'm aware of that.
DMA 200 S2 input impedance is 10.000 ohms and AR LS 25 MkII is 320 ohm in single-ended (now is connected in Single Ended, not the 600 ohm balanced).  The general thumb rule of 10x is respected and the most restricted Audio Research thumb rule of 30x is in the limits.
In the facts, i.e. listening, LS25mkII sounds great with no roll off or problems.
Of course, in balanced mode, the ss smp should be 20k minimum for the same rule.

I see Ref 6 (and Ref 5 se) has the same output impedance.