My exerience was mostly with Nautilus 800's -- very little with the 805sig. However it may be useful for Glai & Bigkidz.
Gvatchna: my experience using Symphonic Line tallies with yours. On the 805's (a brief, 1hr, audition), a Kraft 250 ref slightly outclassed the RG4's in musicality, nuance and control. OTOH, the RG4 driving the 805's sounded, subjectively, ever so slightly "faster"... The differences b/ween RG4 and Kraft 250 were more than evident on the 800's: there with the Kraft we had detail and an "iron" control in the lower end -- indeed, the louder we played, the better (more open, more headroom???, more detailed) the sound became.
We also tried a tube -- a pair of KR mono's (allegedly an SET design with proprietary tubes -- huge) that drove the 805's very well. On the 800's we had a feeling that loud Mahlerian passages were a little compressed -- but that may have been an impression.
Please note that this was NOT a "critical auditioning" session -- just playing around (none of us could afford the 800's anyway) -- so after the first 2hrs or so, we ended up listening just to the 800's driven by the Kraft 250. Not that we rejected the 805's... but those belonged to a friend while the 800's to a dealer, so we grabbed the chance to play w/ the 800's :)!
Pre was a CAT Ultimate. Cheers
Gvatchna: my experience using Symphonic Line tallies with yours. On the 805's (a brief, 1hr, audition), a Kraft 250 ref slightly outclassed the RG4's in musicality, nuance and control. OTOH, the RG4 driving the 805's sounded, subjectively, ever so slightly "faster"... The differences b/ween RG4 and Kraft 250 were more than evident on the 800's: there with the Kraft we had detail and an "iron" control in the lower end -- indeed, the louder we played, the better (more open, more headroom???, more detailed) the sound became.
We also tried a tube -- a pair of KR mono's (allegedly an SET design with proprietary tubes -- huge) that drove the 805's very well. On the 800's we had a feeling that loud Mahlerian passages were a little compressed -- but that may have been an impression.
Please note that this was NOT a "critical auditioning" session -- just playing around (none of us could afford the 800's anyway) -- so after the first 2hrs or so, we ended up listening just to the 800's driven by the Kraft 250. Not that we rejected the 805's... but those belonged to a friend while the 800's to a dealer, so we grabbed the chance to play w/ the 800's :)!
Pre was a CAT Ultimate. Cheers