Link Switch; Operating Modes; Options; Stereo Mode - Martin Audio MA4.2s User Manual

< >
CONTENTS
5.1.3
A s th e D IP -sw itch is rece ssed , a sticke r ca n b e p la ce d a cross the cu t ou t to pre ve nt un au th o rize d tam pe rin g. An othe r
o ptio n is to re mo ve th e D IP -switch . T his sh o uld o nly be do ne by a uth orize d se rv ice p e rs on ne l. T his co rre sp o nd s
to all switch es set to "O FF ", i.e . 3 2d B ga in an d ste re o m od e .
5.2

Link switch

T he L in k switch loca te d o n th e rea r p an el (the ce ntra l D IP -sw itch ) is fo r cha ng ing th e op era ting mo de o f the am plifier
(se e be low , section 5.3).
5.3

Operating modes

NOTE: Channel B is always polarity reversed on the input, and polarity reversed back on the output. On channel B
the positive output voltage with respect to 0V appears on pin -2 of the Speakon connector. Channel A is connected
with normal polarity. By having channel A and B operating in opposite polarity, the energy storage in the power
supply is more efficient. This is significant for signals below 100 Hz (sub bass etc.) and improves the power
bandwidth. Be sure to use balanced inputs on all measuring equipment (including oscilloscope probes) if
you are bench testing.
Reverse operation of Channel B.
5.3.3
In tandem mode channel A input is linked to channel B input, either input socket may then be used to provide the
input signal. Tandem mode is activated by placing the two central switches (4 and 5) in the "ON" position (UP).
Both input attenuator's are active, allowing you to set different levels for each channel. Note that only the inputs are
connected in parallel. This is NOT a parallel output mode. Never connect either output terminal to ground or in
parallel.
You can use the remaining input connectors to parallel off "Daisy – chain" signals to other amplifiers.
NOTE: Always turn off the Link switch when using the amplifier for Bi-amping.
All material © 2007. Martin Audio Ltd. Subject to change without notice.
PRINT

Options

5.3.1

Stereo mode

In this configuration, both channels operate independently of each other. This is used
for all 2-channel operations, e.g. bi-amp and stereo. Stereo mode is selected by
placing the two central switches in the "OFF" position (Down). The attenuators on the
front panel control the respective channels levels.
Never connect either output terminal to ground or in parallel. The recommended
minimum nominal impedance, for stereo or tandem operation, is 2 ohms per channel.
5.3.2

Notes for amplifier testing

Tandem mode

Martin Audio – MA4.2s Amplifier
7
GUIDES