Mojotone Bias Checker Kit by Hoffman Amps

SKU: 4152002
Weight: 0.17 lb
Sale Unit: Piece

In Stock


The Mojotone Bias Checker Kit by Hoffman Amps is the best of both worlds when it comes to ease of assembly and cost effectiveness. This kit is easy to build, and comes with assembly instructions in the link below. 

Kit builds one bias probe to be used with a multimeter
Materials list for each Bias Current Checker:
  • 1 - 8 pin tube base with hole and sticker
  • 1 - 8 pin PC board tube socket
  • 1 - Dual banana plug
  • 1 - Bias checker PCB
  • 1 - Bias checker Ring
  • 1 foot of 18 gauge zip cord
  • 2 feet of buss wire

Ratings & Reviews

2 reviews

  • 3 stars
  • 0 reviews
  • 2 stars
  • 0 reviews
  • 1 star
  • 0 reviews
3/31/2023 9:42 am

Longer Cord Needed But Works Great

by Brad -

Only giving it 4 stars because the red and black cord included is just way to short. Which makes it difficult to position your meter when using it. Everything is is great and works great.

12/12/2021 9:35 am

Buy 2 pairs or quads. Move the testing leads to pin 6 instead of pin 8 and test 7591s!

by S.E. Burgin: Applied Analog Audio Amplification & Klesi Music. -

You can rewire these with the test leads coming off of pin 8 instead of pin 6 and each will test 7591s or 7591As. As the instructions show, you can test: 6K6, 6W6, 6V6, 6L6, 6L6G, 6L6G, 6L6GA, 6L6GB, 6L6GC, 5881, KT66, 7581, 7027, 6550, KT77, EL34, EL37, KT88, 6550 and 8417 tubes for cathode current. A slight alteration and by moving the wires to test the amperage on pin 6 and these become a dedicated tester for 7591 tubes. As the instructions show these will NOT test 7591s or 7591As! I prefer adding a 1 ohm 1 Watt +/-1/2 or +/- 0.1 % resistor and testing the voltage across the resistor. Ohm's law makes the milliamps = millivolts. Either way works. I like Mr. Hoffman and his products.