ESL audio First One
orders & support: [email protected]
First One M module in stereo connection
In most cases First One M modules will be
used as a part of stereo power amplifier for
which connection diagram is proposed below
(Fig.1), where two First One modules operates
together in a single metal chassis.
Each of the RCA input connectors has to be
electrically isolated from the metal chassis.
Cable connecting RCA terminals to PCB pads
has to be as short as possible, double shielded
coaxial cable of 50 to 75 Ohm impedance is
recommended. Although a twisted pair of a
solid core wires can also be used if an internal
input connection length is shorter than few cm.
Speaker output connector terminals have to be
mechanically heavy duty variant, capable of
conducting high currents. Normally each of
them has to be electrically isolated from the
metal chassis. Internal wiring from power
supply to all amplifier power connections has
to be made by isolated properly coloured wires
of minimal 1,5 mm² cross-section area.
Special attention has to be dedicated to earth
reference point of a metal chassis (Fig.1).
Properly done with electrically well conducted
bolt connected to the metal chassis in a one
point, therefore all the parts of a chassis (all
metal plates, heatsinks) are connected to the
earth potential. GND power supply terminal J2
from each First One module is connected to
GND terminal of its power supply only (Fig.1).
GND potential of both channels are isolated
between each other and earth potential, in this
way modules are prevented from unwanted
ground loops interference currents to flow
between channel's GND potentials.
Powering stereo amplifier can be realized by
single power supply for both channels or by
two power supplies, each for separate channel
in a so called dual-mono configuration. Later is
preferred and recommended as more reliable
and higher performance solution (Fig.1). As
already mentioned the best sonic result is
achieved by using unregulated switch mode
power supply of at least 600 W or more output
power per one First One module's channel.
Fig.1 Schematic diagram for stereo connection
2
