VHT Tube Tester + Amp Bias Meter – StewMac

VHT Tube Tester + Amp Bias Meter

Set your amp’s bias the right way
Tubes don’t have a predictable life, but you can measure how they are performing in your amp. The VHT Tube Tester lets you see how current (measured in milliamps or mA) is affecting your tubes and where to set the bias on your amp. Setting the bias correctly is essential for achieving optimal tone and performance, and keeping your amp running safely.

Swap power tubes without fear
VHT sells this as a “tube tester”; we find its best used as a tool to find and set your amp’s bias. The bias is the current flowing through the amp when idle. Once you know how your tubes are working you can find the perfect bias setting for your amp, maximizing the amp’s performance and the life of the power tubes. The tester works for all popular octal-base output tubes (6V6, 6L6, EL34, KT66, KT77, KT88, 6550, and more).

This is one of the most affordable tools to measure an amp’s bias, and see how two tubes perform at the same time. There is no need to modify the amp or tube sockets. You also have the option to plug in your favorite analog or digital multimeter for calibration or more precise measurements. The two foot long cables allow you to reach into any head or combo.

Get the right tool for servicing your amp and changing tubes!

VHT Tube Tester includes:
• Two standard 8-pin octal-base adapters with dual banana plugs, cloth covered, two feet in length
• Adapters accept all popular octal-base output tube types (6V6, 6L6, EL34, KT66, KT77, KT88, 6550, etc.)
• Two high-quality 3″ diameter metal and glass analog milliamp meters (100mA max)
• Additional test-pin jacks for external digital multimeter connection
• Durable vinyl-covered wood cabinet
• Requires no external power