Unless the amp is noisy give the tubes some time to break in. If it's noisy then you probably got a bad tube. Also if you hear something through the speakers when tapping on the preamp chassis you've got a microphonic tube. It happens no matter what the sellers tells you. Most will swap them out for you. That's when you know you got a good dealer.
My experience with ARC is that they were designed and voiced around the Russian tubes so it shouldn't sound that bad.
My experience with ARC is that they were designed and voiced around the Russian tubes so it shouldn't sound that bad.