135W Fender Twin is slowly burning up phase inverter tubes after a recap.

[kg]

I don't know of a power amp modification to warm up the tubes(accidental pun), except maybe adding small resistors in series with the plates to cause sag.

run 'em really really hot. i believe i was in the 50w pdiss range before i got slight red spots...

[jmaf]

run 'em really really hot. i believe i was in the 50w pdiss range before i got slight red spots...

50W EACH TUBE Haha! Now that's warm tone

[Gtr_tech]

With the 5881's I've never seen one go bad...never.... The WXT+'s are very sturdy as well, and cheap as they come.

The WXT+ is a better sounding tube as compared to the "5881" Sov variants.....just not real durable in an amp with screen taps.