Ferrograph Logic 7 Service Manual

Ferrograph Logic 7 Service Manual

The following pages are scanned from a Ferrograph Logic 7 Service Manual, kindly donated by Andrew Button.

This manual is also available as a high resolution PDF file (10.6MB).

This manual covers the majority of Logic 7 tape recorders, which use an idler wheel system to drive the capstan. It is thought that a small number of Logic 7s (from serial number 110,000) were fitted with a direct drive, servo controlled capstan, similar to that used on the Studio 8 recorders. I would be very interested to hear from owners of such machines.

This service manual includes information on the setup and alignement of the Dolby B noise reduction system. This information should also be useful to owners of Dolby equipped Series 7 and Super 7 machines, which use a similar implementation of the Dolby system.

Each page is approximately 60KB, except where stated otherwise.

Service Manual

• Front Page
• Page 1, Contents
• Page 2, Contents cont.
• Errata
• Page 3, List of Illustrations
• Page 4
• Page 5, Specification
• Page 6
• Page 7, Section 1 - Technical Description
• Page 8, 1.1 Mechanical
• Page 9
• Page 10
• Page 11
• Page 12
• Page 13, 1.2 Electronic Section
• Page 14
• Page 15
• Page 16
• Page 17, 1.3 Dolby Section
• Page 18, Block Diagram - Dolby NR System
• Page 19
• Page 20
• Page 21
• Page 22, Section 2 - Faults Analysis, 2.1 Electro-Mechanical Faults
• Page 23, 2.2 Electronic Faults
• Page 24
• Page 25, Section 3 - Removal/Replacement
• Page 26
• Page 27
• Page 28
• Page 29
• Page 30
• Page 31, Track Configuration
• Page 32, Section 4 - Tests & Adjustments
• Page 33, 4.1 Mechanical
• Page 34
• Page 35
• Page 36
• Page 37, 4.2 Electronic
• Page 38
• Page 39
• Page 40
• Page 41
• Page 42
• Page 43
• Page 44
• Page 45
• Page 46
• Page 47, 4.3 Dolby
• Page 48
• Page 49
• Page 50
• Page 51
• Page 52, 4.4 General
• Page 53
• Page 54
• Page 55, Section 5 - Parts Lists
• Page 56, 5.1 Mechanical
• Page 57
• Page 58
• Page 59
• Page 60, 5.2 Miscellaneous

Electronic Parts Lists

• Page 7, Front Page
• Page 8, Dolby NR Processors
• Page 9, Deck Unit
• Page 10, Logic & Power
• Page 11, Record & Replay
• Page 12, Tone, Oscillator, and Power Amplifiers
• Page 13, Power & General
• Page 14
• Page 15, For Figure 29a - Dolby Circuit Diagram, see below.
• Page 16, For Figure 29b - Phones Amplifier, see below.

Diagrams and Illustrations

These diagrams have been scanned from poor quality originals, and in many cases the small text, component numbers, etc., have been replaced in order to increase the legibility of these low resolution images.

Figure 11, the components chart, has been omitted due to the poor quality of the original.

Figure 29, the Dolby NR Circuit Diagram, is a link to the identical diagram in the Dolby supplement to the Series 7 User Manual.

• Figure 12, Mechanical Components - Deck (200KB)
• Figure 13, Chassis Dimensions
• Figure 14, Effect of Bass and Treble Controls
  Figure 15, Low Level Characteristics of Record and Replay Dolby Processors (100KB)
• Figure 16, Record Processor Characteristics (100KB)
• Figure 17, Low-Level Frequency Response of Record Processor Under High Level Signal Conditions
  Figure 18, Record Transfer Characteristics - 1kHz and 5kHz (100KB)
• Figure 19, Record/Replay Response - Level Mismatch (100KB)
• Figure 20, Dolby Record Processor Board
  Figure 21, Dolby Replay Processor Board (90KB)
• Figure 22, Amplifier - Front View
  Figure 23, Amplifier - Rear View (60KB)
• Figure 24, Recorder - Rear View
  Figure 25, Power Unit - Rear View (75KB)
• Figures 26 and 27, Record Amplifier Boards - Upper and Lower (80KB)
• Figure 28, Oscillator Board
  Figure 31, Pre-Emphasis Board (75KB)
• Figure 29a, Dolby NR Circuit Diagram (320KB) (Link to diagram in Series 7 User Manual).
• Figure 29b, Phones Amplifier (20KB)
• Figure 30, Circuit Diagram (600KB)
• Figure 32, Replay Board
  Figure 33, Power Amplifier Board (70KB)
• Figure 34, Tone Control Board
  Figure 35, Power Board (50KB)
• Figure 36, Logic Board
  Figure 37, Motion Sensor Board (65KB)
• Figure 38, Block Diagram - Standard Models (70KB)
• Figure 39, Block Diagram - Dolby Models (70KB)
• Figure 40, Phones Board (350KB)