for the inputs and attaches to a socket on the left side of
the board; on the other side is a barrier strip with screw
terminals for the left and right speaker outputs and power
supply connection. That's one of my favorite things about
this module since it will make it so easy to integrate it into
other projects with a minimum of messing around with
external controls and switches. It'd be
easy to attach a volume control pot to
the input if needed, but I'm envisioning
this one being great in applications where
the audio signal is being controlled by a
pre-amp or receiver — like the Wi-Fi
Internet radio project shown in Photo 14.
The Tripath TA2024 is a decent little
chip itself. It can deliver up to 15W into a
four ohm load at 10% THD+N, but is
rated for "audiophile" quality sound at up
to 9W at 0.04% THD+N (Photo 15).
Naturally, this is going to depend on the
implementation, which can really throw it
off if it's done poorly. Fortunately, though,
this module delivers pretty close to its
specified performance. It's close to the
reference design from the datasheet, as
well (Photo 16, Photo 17, and Photo 18).
I'd call this a very solid
implementation; performance is very
close to the datasheet figures. While
everyone's ears are a little different, most
people can't pick out distortion below
about 1% unless they're specifically
looking for it. This module delivered 11W
into a four ohm load at only 0.7%
THD+N. At 9W, it was well into the
audiophile quality range, with only
0.082% THD+N — a bit higher than the
theoretical figure of 0.04% THD+N, but
very respectable nonetheless. This is a
good little board!
One thing about this particular module ... it only
delivered the low distortion into a four ohm load. It's rated
for much less power into an eight ohm load, but
comparing performance at 5W, the module delivered
0.55% THD+N which is much higher. Certainly listenable,
PHOTO 16. The model TA2024 amplifier module under test.
PHOTO 17. Model TA2024 THD+N measured into four
and eight ohm loads from 0.25W through maximum
power output.
March 2015 51
PHOTO 18.
Tripath TA2024
chip amplifier
reference circuit,
from the
manufacturer's
datasheet.