Rebbi,
I have respect for Paul Joppa and his bottle head products. AN Kits have really eared a strong reputation for their design,part quality options and built. Both of these are to a degree built to fit a price point. This is why upgrade options are offered.
Art audio begins at a higher price point, their stock parts are the other two amp's higher upgrade level. I would lean toward the Art Audio and replace the bad tube. This is a very highly regarded SET amplifier. The PX 25 is less common than the 300b but they are certainly available.
Any of these 3 choices are good at their price point. A used Art Audio in good condition is very tempting.
I have respect for Paul Joppa and his bottle head products. AN Kits have really eared a strong reputation for their design,part quality options and built. Both of these are to a degree built to fit a price point. This is why upgrade options are offered.
Art audio begins at a higher price point, their stock parts are the other two amp's higher upgrade level. I would lean toward the Art Audio and replace the bad tube. This is a very highly regarded SET amplifier. The PX 25 is less common than the 300b but they are certainly available.
Any of these 3 choices are good at their price point. A used Art Audio in good condition is very tempting.