TRACE ELLIOT GP12 SMX SERIES User Manual

TRACE ELLIOT
SERVICE MANUAL
DATE : December 29, 1999
Product Code: N/A
Model Number : GP12 300 WATT SMX SERIES
This unit has used two issues of 300 watt MOSFET power board.
The Bi-polar Bear and the 300 Mosfet Board
Details for both are included in this manual.
You should check which board you have in your unit before
attempting any repair.
The Bi-polar board is marked PC00026
The MOSFET board is marked PC00083
Issued by:
Trace Elliot Limited
Blackwater Trading Estate
The Causeway
Maldon
Essex
England
CM4 4GG

TRACE ELLIOT GP12 SMX SERIES Specifications

General

Brand	TRACE ELLIOT
Model	GP12 SMX SERIES
Category	Amplifier
Language	English

Summary

GP12 SMX Circuit Description

Input Blend and Input Gain

Dual gang potentiometer for balancing valve/FET signals and amplification via IC1.

Graphic Section

Graphic equalization section configured around IC5 covering six frequency bands.

Dual Compressor Section

Signal split into low/high pass filters for separate compression circuits.

Pre-Amp Supply Regulation

Details transformer, rectifier, filter, and regulator circuits for +/-15V and 150V HT supply.

Bipolar Bear PC00026 Circuit Description

Input Stage

Voltage Amplification Stage

Output Stage

Short Circuit Protection

TR12/TR5 protect output transistors via 'foldback current limiting'.

Power On Mute

Relay RL1 limits output swing during power up/down to prevent loud 'bangs'.

Important Notice

Servicing Guidelines

Advises replacing output transistors, TIP31/32, and TR11 during servicing.

Output Device and Driver Stability

TR11 Heat Transfer

TR11 must be covered in HTC to maintain correct bias at high temperatures.

Bias Adjustment