4
Making Connections
The Inputs on the Back
• One Pair of Unbalanced RCA Jacks
• One Pair of Balanced XLR Female
Connectors
• One Power Control (Trigger) Input
• One Power Control (Trigger) Output
• One AC Power Inlet
Balanced or Unbalanced Input
The BALANCED INPUT allows a source to be
connected using Balanced (XLR) cables (see Figure
03.)
The Unbalanced Input accepts RCA/Phono Plugs
(see Figure 05.)
Choose either Balanced or Unbalanced as an Input
source for the MHA200. Connecting both is not
optimal.
You may wish to use a fixed output source and
control the volume solely with the MHA200 Volume
Knob. You may use a variable volume source and
use the source (a preamplifier for example) to
control volume. In this case the Volume Knob of the
MHA200 can be left at unity gain with the notch at
12 o’clock (at the top).
Trigger Input
The Trigger Input can be connected to other
McIntosh equipment using a 3.5mm stereo mini
phone plug to receive a +12 Volt/0 Volt signal for
power control (see Figure 06). When a signal is
received, the MHA200 will power on.
Trigger Output
The Trigger Out is an output that can be connected
to other McIntosh equipment using a 3.5mm stereo
mini phone plug to send a +12 Volt/0 Volt signal
for power control. This will enable additional
equipment to be powered on and off when the
MHA200 is powered on or off.
AC Power
Use the included AC Power Cord to connect the
MHA200 to a working AC outlet. Make sure the
Voltage matches the value printed above the AC
Connector on the right side of the rear of the unit.
The Knobs on the Front
The Left Knob (Load)
The Left Knob, aka the Load Knob, allows you
to impedance match the MHA200 with your
headphones. Set the Left Knob to the value closest
to the impedance value specified by your headphone
manufacturer. The options are:
• 32 ohms
• 100 ohms
• 250 ohms
• 600 ohms
There is no need to be exact since the impedance
rating of a headphone is an average of the varying
impedance across the frequency range. Choosing
a value above your headphone’s impedence, will
result in louder output (and visa versa).
The Right Knob (Volume)
Turn clockwise for more volume and counter-
clockwise for less volume.
Figure 03– Rear Panel
POWER
CONTROL
IN
OUT
L
R
L
R
BALANCED
UNBALANCED
INPUTS
120V 50 60Hz
/
50 WATTS
Figure 05– RCA Cable
Connect components for
Power Control using a
3.5mm stereo mini plug
.
Power
Control
Meter
Illumination
Control Ground
Figure 06– Power control (trigger) mini plug
PIN 1
PIN 2
PIN 3
Figure 04– XLR cable
PIN 1: Shield/Ground
PIN 2: + Signal
PIN 3: - Signal
