serost, Товарищ Fender в общем исчерпывающе ответил. Все есть в инструкции, которую блогеры обычно не читают и поэтому обзоры получаются беглые и очень поверхностные =)
Ну и это очередное подтверждение моих слов выше, что Iridium более гибок, но менее эмулирует "оригинал". Это необходимо просто принять и пользоваться в свое удовольствие.
round
Based on* a Fender® Deluxe Reverb®, this amp
is clean, bright, and mid-scooped, with plenty
of headroom. While preserving access to all the tones originally
available from the Deluxe’s Normal channel, our amp gives you
something extra: a midrange control. With the MIDDLE knob at
noon, you get the original fixed-resistor value and standard tonal
characteristics of the Deluxe. Turn down the MIDDLE control for a
more scooped sound, or turn it up for tweed-era tones.
chime
Based on* the Brilliant channel of a Vox® AC30TB, this amp is jangly
and bright, providing air for subtle passages with a light touch, and
bite when you want to dig in. The MIDDLE knob acts a tone cut knob,
providing high-end roll-off just before the power tubes, per the
AC30TB design. In addition to the full available gain of the original
amp, toward the top end of the DRIVE knob’s range of travel, we’ve
added a frequency-shaped front end boost to tighten the low end
while driving the amp further into saturation.
punch
Based on* a Marshall® Plexi (Super Lead model number 1959), this
powerful amp is meatier, with higher gain than the other two amps,
and has a powerful midrange response. This amp features a buttery,
smooth overdrive. Setting the DRIVE control at around 2 o’clock
gets you the maximum gain the original Plexi design allowed. Turn
the DRIVE beyond 2 o’clock to access custom hot-rodded Plexi high
gain tones.