Was wondering what criteria you use to adjust the resistor? Clues on the test bench or sound qualities? And which way to go with resistor values? Thanks in advance.
Some of both. If the amp is showing too much distortion, I lower the value. But sometimes lower values can kill off the top end, so if the amp sounds dull, try a higher value. If it's too bright, try a lower value. I've used everything from 150K to 1M depending on the amp.
It's possible but there are issues with doing that, mainly finding perfectly matched tubes. That could be harder than finding a good pair of KT120 tubes!
Some of both. If the amp is showing too much distortion, I lower the value. But sometimes lower values can kill off the top end, so if the amp sounds dull, try a higher value. If it's too bright, try a lower value. I've used everything from 150K to 1M depending on the amp.