14. INPUT TRANSFORMER INSTALLATION AND ITS BOARD MODIFICATION

Caution: Leave the following work to a qualified service technician.

Be sure to switch off the power before the work.

14.1. Transformer Installation

You can convert the audio input section in Input 1 – 3 terminals, Remote Microphone (RM) terminal, and Telephone Paging (TEL) terminal on the unit from electronically-balanced input to transformer-balanced type. Solder the optional IT-450 input transformer to the required input section.

Step 1. Remove 4 screws on the amplifier rear panel and a total of 6 screws on the sides to remove the cover.

Side: M4 x 8 machine screw

3 pieces each

Rear: M3 x 6 machine screw and M3 plain washer

4 pieces

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Step 2. Removing the input transformer board

[Inputs 1 – 3]

Remove the Inputs 1 – 3 input transformer board, which is installed on the rear upper circuit board in the unit.

[Remote Microphone (RM) or Telephone Paging (TEL)]

Remove the RM/TEL input transformer board, which is installed on the rear lower circuit board in the unit.

Input transformer

RM/TEL input transformer board

Inputs 1 – 3 input transformer board

Rear upper circuit board

Rear lower circuit board

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Image 34
TOA Electronics VM-2120 instruction manual Input Transformer Installation and ITS Board Modification, Inputs 1