Mojotone Bias Checker Kit by Hoffman Amps
Kit builds one bias probe to be used with a multimeter
- 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
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.