Like all of our amps, the ZOTL40 Reference and the Ultralinear both have the magic, realism, and 3D soundstage inherent in our patented ZOTL technology.
Both amps are fast, fluid and do an excellent job of reproducing the pace and punch of the music. Likewise, both amps have the black background, high clarity, accuracy, realism, and dynamics that fool your brain into thinking the performers are in the room with you.
The Ultralinear is a little more relaxed, more refined and a little less forward presentation (more noticeable with higher efficiency speakers). Despite having “only” 20 wpc, it has very strong bass. The Ultralinear has a little more detail than the ZOTL40, and can rival any solid state amp as far as detail goes.
The ZOTL40 uses Mullard EL34 tubes, which is one of the best midrange tubes ever invented, so it has a little less detail and very solid midrange and punch.
Both amps can be used in stereo mode or monoblocked pairs at the flip of a switch, should you require more power.