 location: Portland, OR USA  Facets: sound engineering,
technology, @musings info  DIs, Speaker Simulators and Amp
Modelers  I think a lot of players don't understand the
differences among a DI, a speaker emulator and an amp modeler.
These are commonly-used tools for guitarists who want to play
their instrument "direct to the board", usually in situations
where it's necessary or desirable to minimize stage volume.
Briefly, here's what each unit does:  So why would you use each
of these units, and why use one unit in preference to another?
A DI's sole function is to match an unbalanced signal line to a
balanced signal line. Unbalanced lines are common in guitar rigs
because the circuitry needed to drive the line is inexpensive.
The downside of an unbalanced line is that longer cable runs
tend to degrade the signal by attenuating higher frequencies and
by picking up electrical noise (hum and buzz).  A balanced line
is designed to overcome these limitations at the expense of
additional cost and complexity in t