It is unique in the fact that it shows you both the plate current and plate voltage simultaneously and it is completely self- contained with no switches or batteries. In 2012 we introduced the ET “Pro One” Bias Probe.

No switches, no batteries, no knobs! And only $99.00 See it in action in our latest 'How To' Bias Video! The ET “Pro One” Octal Bias Probe. If you have lost your instruction sheet for one of these probes you can find a copy HERE. We try to keep a carton or two of our $10.00 'Cheap Multimeters' on hand and if you see them in the online store they are in stock. These probes are $25.00 and available in our online store and can be used with 6V6 - E元4 - E元4II - E34L - KT77 - 6CA7 - 6L6 - 6L6GC - KT66 - 6550 and KT88 tubes. We will continue to offer these because in conjunction with a Multimeter this is the most cost effective tool for measuring true plate current allowing you to accurately bias your amp. Since 2006 we have offered a single octal bias probe for use with a Multimeter.

Check bias guitar amp tubes