Hey,
Does anyone have experience with an Amplitrex AT1000 tube tester? (Specifically, using one to test tubes for use in guitar amps?)
I just got one, and I'm now massively confused in terms of how to use it and what the results mean. In the stock Fixed Bias mode, a ton of tubes I've tested which are either new or (I'm told from reputable dealers) NOS are testing low on emissions in particular...
Googling has only confused me more... some people saying it should be in Fixed Bias mode, others that it should be in Auto Bias mode, others that this tester gives false low readings for tubes, one guy saying you have to use the computer mode and do all sorts of fancy software mods in order to get accurate results...
Can anyone tell me: a) should it be in fixed bias more or auto bias mode and b) how to interpret the results (what are the thresholds for emission, gm that correspond to "good", "on it's way out," "weak")?
I'm testing tubes for use in basically Fender-style amps that have fixed bias, FWIW...
Thanks!
Does anyone have experience with an Amplitrex AT1000 tube tester? (Specifically, using one to test tubes for use in guitar amps?)
I just got one, and I'm now massively confused in terms of how to use it and what the results mean. In the stock Fixed Bias mode, a ton of tubes I've tested which are either new or (I'm told from reputable dealers) NOS are testing low on emissions in particular...
Googling has only confused me more... some people saying it should be in Fixed Bias mode, others that it should be in Auto Bias mode, others that this tester gives false low readings for tubes, one guy saying you have to use the computer mode and do all sorts of fancy software mods in order to get accurate results...
Can anyone tell me: a) should it be in fixed bias more or auto bias mode and b) how to interpret the results (what are the thresholds for emission, gm that correspond to "good", "on it's way out," "weak")?
I'm testing tubes for use in basically Fender-style amps that have fixed bias, FWIW...
Thanks!