Spent a couple of hours changing tubes today. I hate dismantling rack gear, it's always such a hassle. Because I've been running out of NOS (new original stock) tubes and money, I've switched one channel of my microphone preamp to a TAD 7025 WA HIGHGRADE RT080. I've used TAD tubes for guitar amps before, but I was hesitant to use them in a microphone preamp. However, after a few hours of burn in time it sounded quite good and I think I will probably pass on vintage tubes in the future, they have become ridiculously expensive over the last years.