Univex Dual Mono Pre-Main Amplifier AM-77 - Manual (Page 54)

54
5b. ‘HiFi/Pro’ Switches for Balanced XLR inputs
For the majority of sources, the HiFi/Pro switch (R3) is best left in the ‘HiFi’ position. However, if the source has
a pro-audio style transformer balanced output, the HiFi/Pro switch needs to be set to ‘Pro’.
A transformer balanced output uses a floating secondary from an audio transformer: unlike electronic balanced
outputs of any description, the signal is NOT referenced to ground (Pin 1). For such (rather rare) equipment, the
‘Pro’ switch is engaged to short-scircuit Pins 1 & 3, thus establishing the ground connection.
‘Pro’ switch is for
the few pre-
amplifiers that
have floating
transformer
balanced outputs
HiFi Pro
Mode
Int
Amp
Power
Amp
L R M
Power
On Off
Sync
Balanced Input
Designed and Engineered in Great Britain Dual Mono Amplifier AM 77 -
+ + _ _
90V 135V 190V 260V
～ AC IN
Speaker Output Speaker Output
L R
IR Link
L
R
1 5 4 3 2
Inputs
No User Serviceable Components Inside . , . . For service contact your Authorised Dealer or Distributor Any modifications to this equipment will void all warranties
CAUTION ATTENTION
RISK OF ELECTRIC SHOCK DO NOT OPEN RISQUE DE CHOC ELECTRIQUE NE PAS OUVRIR
! , ( ) . . Under normal operation set all switches to
the default position Please refer to the instruction manual for further details bold
HiFi Pro
Mode
Int Amp Power Amp
-
Option
SERIAL NO .
L R M M
In Out
AM 77 - AM 77 -
M
M M