5b. ‘HiFi/Pro’ Switches for Balanced XLR inputs

‘Pro’ switch is for

the few pre-

amplifiers that have floating transformer balanced outputs

HiFi

 

 

 

 

Pro

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Mode

 

M

L R

M M

Power

Int

Amp

Amp

Speaker

Output

+

_

 

 

HiFi

Pro

R

Mode

M

L R

M M

Power

Int

Amp

Amp

Under normal operation,set all switches to

the default(bold)position.Please refer to

the instruction manual for further details.

Balanced

Input

 

Dual Mono Amplifier AM 77

In

Out

 

Designed and Engineered in Great Britain

 

 

1

2

3

4

5

 

Sync

 

 

 

 

L

 

 

 

 

 

 

 

 

IR Link

 

 

 

 

R

 

 

 

 

 

 

 

 

Option

 

 

Inputs

 

 

 

 

CAUTION

ATTENTION

 

 

No User Serviceable Components Inside.

 

!

For service,contact your Authorised

RISK OF ELECTRIC SHOCK

RISQUE DE CHOC ELECTRIQUE

 

Dealer or Distributor.Any modifications to

DO NOT OPEN

NE PAS OUVRIR

 

this equipment will void all warranties.

AM-77

Power

On

Off

AC IN

90V

135V

190V

260V

Speaker

 

Output

 

_

+

L

 

SERIAL NO.

 

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.

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Univex AM-77 owner manual HiFi Pro