Bias Master™ system BM4 Measures Bias current of the vacuum tubes in your amp. Includes 4 probes and english/german operation manual.

The Bias Master™ allows you to monitor the bias current safely and easily. While adjusting the Bias control pot of your amp, the Bias Master™ shows the actual result. This lets you set and evaluate the full reasonable biasing range your amp and tubes offer to find and set your personal perfect choice.

The Bias setting has a dramatic impact on the amp's response, break-up and dynamic character.

  • Probe Type: Octal
  • Measures: 6L6GC, 6550, EL34, 6V6GT, 5881, KT66, KT88, KT90, KT100, KT120, 7027A

For additional probes (for testing other types of tubes), see S-TBMA2-X


Product Measurements

Item Length: 5.76 in.
Item Width: 3.6 in.
Item Height: 2.1 in.

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ConditionBrand New (New)
Brand New items are sold by an authorized dealer or original builder and include all original packaging.Learn more
Brand
Model
  • S-TBM4
Categories
Year
  • 2026

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Tempe, AZ, United States
Joined Reverb:2013

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