The ZOTL and the RS-1 are a good combination with potential. The RS-1 sounds very good with this amp. However, there is something off that's particularly apparent in music such as female vocals. On Jennifer Warnes' "The Well", the RS-1/ZOTL combo makes her sound as though she's not drawing breath properly. It's not a full sound, almost nasal. Switch to the EAR, and you can hear the full range of the vocals. On other types of music, such as blues guitar, differences are much less noticeable.
As it stands, the RS-1 is more sensitive to differences between the EAR and the ZOTL right now than the R10. Curious.
This isn't saying the RS-1 is bad with the ZOTL. I've heard the RS-1 sound bad, and this isn't it. This is a direct comparison with an amp that lists for almost five times the price of the ZOTL in the US. Also, the Ken-Rads I'm using in the ZOTL are probably not the best tubes for this particular type of music, where the differences are most apparent. Sylvania VT-231's may well resolve this issue (at a cost to the low end).
