[Big Bad Bob]

On 02/17/16 16:31, Patrick Turner so wittily quipped:
There are just too many variables involved. But I do recommend that ppl interested go to their workshop, solder up a circuit, document it fully, post all results with schematic at a website, and then everyone will know what are the facts, well, pending presentation without errors.

ack, there are plenty of curves and equations described online in
various sources describing the behavior of pentode amplifiers, and they
can have VERY high gain if you set them up right, but maybe you're
simply explaining why I prefer to use triodes.

12AX7 good enough for Leo Fender, should be ok for me, heh.

A bipolar transistor single-stage amplifier can have a gain of 1000. I
wouldn't want to hear the audio quality of that, not at all. use an
emitter resistor (like unbypassed K resistor on pentode) for NFB and
keep the actual stage gain a bit lower, and all that gain might keep the
signal:noise and distortion down.

hard to say which is better. build and test, measure with good
equipment, use low noise metal film resistors and high quality
capacitors, shield the tubes, and additional low capacitance filtering
in the power supply in parallel with electrolytics...