ORANGE VALVE TESTER MKII - User Manual

The Orange Valve Tester MKII is a compact, safe, and simple device designed to test and grade vacuum tubes (valves) used in guitar amplifiers and other audio equipment. It provides an automatic and accurate way to assess valve condition, offering a modern alternative to traditional, often complex, valve testers.

Function Description:

The primary function of the Orange Valve Tester MKII is to automatically test and grade vacuum tubes. It performs thousands of micro-measurements and a wide array of tests to assess the condition of a valve, including its emission, control grid performance, and potential failure modes. The tester is designed to be user-friendly, requiring minimal interaction and no in-depth knowledge of valve theory. After a test, it provides a clear indication of the valve's status (GOOD, WORN, or FAIL) and a "matching number" that reflects its operational characteristics in an audio amplifier. For double triode pre-amp valves, it can test both sides (A and B) and indicate their individual matching values. The device also features a microphony test mode for pre-amp valves and supports external expansion modules for testing additional valve types.

Important Technical Specifications:

• Power Input: 19V DC 65W.
• DC Input Socket: Centre positive polarity, standard 2.5mm barrel plug. It is highly recommended to use the supplied power supply or an exact equivalent to prevent product damage.
• Valve Sockets:
  • One socket for octal power valves (e.g., EL34/6CA7, 6L6, 6V6/6V6GTA, KT66, KT77, KT88, KT120, 6550, 5881, and Expansion Module).
  • One socket for EL84 valves (EL84/6BQ5).
  • One socket for pre-amp valves (e.g., ECC81/12AT7, ECC82/12AU7, ECC83/12AX7, 12BH7).
• Display: LED bar display for matching value (1-15) and status indicators (GOOD, WORN, FAIL).
• Control Buttons: Centre button for selecting valve type and starting the test; two outer buttons for navigating valve selection.
• Technology: Incorporates TubeSync® Technology and a sophisticated microprocessor-controlled testing system for precise inter-electrode switching and measurement.
• Compliance: Complies with Canadian Interference Regulations CAN ICES-3(B)/NMB-3(B) and Part 15 of the FCC rules.

Usage Features:

• Automatic Testing: The VT MKII is fully automatic, performing a wide range of tests quickly and accurately without requiring manual parameter settings.
• User-Friendly Interface: Operation involves inserting the valve, selecting its type using up/down buttons and an LED bar display, and pressing an 'OK' button to start the test.
• Clear Results: Test results are indicated by three LEDs (GOOD, WORN, FAIL) and a "matching number" (1-15) that reflects the valve's gain and performance characteristics.
• Double Triode Testing: For pre-amp valves with two internal triodes, the tester provides two matching value LEDs (one flashing for section A, one constant for section B).
• Microphony Mode: A dedicated mode for testing microphony in pre-amp valves (ECC81, ECC82, ECC83, 12BH7). The user taps the valve gently with a pencil, and the LED bar indicates the level of microphonic disturbance.
• Expansion Modules: The device supports external expansion modules, allowing for the testing of additional valve types such as rectifiers and EF86s, and directly heated valves like the 300B.
• New Features in MKII:
  • More rugged mechanical design with improved test sockets.
  • Enhanced grid leakage detection test.
  • Improved algorithm with higher current capability.
  • New microphony function for ECC81, ECC82, ECC83, and 12BH7 pre-amp valves.
  • Valve failure mode identification (indicated by FAIL LED and a number 1-8).
  • New thermal runaway test.
  • Capability to function with external expansion modules.
  • Capability to test directly heated valves via expansion module.

Maintenance Features:

• Environmental Considerations:
  • Use the VT MKII in a location where temperature and humidity remain constant to ensure consistent readings.
  • Allow the device to stand for about 30 minutes out of its packaging before initial use to allow any condensation to subside, especially if brought into a warm room.
  • Ensure plenty of space (> 6"/12.5cm) around the unit for heat dissipation during normal use.
• Valve Handling:
  • Always ensure valves are cool to handle before removing them from the tester.
  • Valves are fragile; handle them gently when inserting or removing them.
  • Do not test hot or warm valves, as this can lead to false readings. Allow valves to return to room temperature before testing.
  • Use protective gloves when handling valves, especially after testing, as they can get hot.
• Safety Precautions:
  • Do not expose the apparatus to rain or moisture.
  • Do not use in damp environments (e.g., bathrooms).
  • Do not place objects containing liquids on or near the product.
  • Do not operate or connect/disconnect the power plug with wet hands.
  • Do not attempt to gain access to the interior of the product; there are no user-serviceable parts inside. Refer all servicing to qualified personnel.
  • Never insert physically damaged valves into the test socket, as this could pose a hazard.
  • If a glass valve envelope is damaged during a test, terminate the test by pressing 'OK' and remove the power connector. Allow the valve to cool, then remove it using protective gloves and dispose of it safely. Ensure no glass fragments remain before using the tester again.
• Troubleshooting (Fault Log): The manual provides a fault log with numbers (1-8) corresponding to specific valve failure modes, such as heater open circuit, heater current issues, anode current issues, screen grid current issues, control grid leakage, and thermal runaway. This helps in diagnosing the reason for a valve failure.