One tip for lower microphonics: choose tubes whose internal plate structure appears robust.
Some tubes have tall, thin vertical plates that look like a gentle breeze would tobble them over. Such tubes TEND to sound bloated, rosy or microphonic.
Other tubes have short, folded or even doubled plates that look sturdy enough to support an elephant. These tubes TEND to sound tighter, more neutral and less microphonic.
The above demonstrates the universal importance of controlling/reducing vibration and resonances in audio equipment of all kinds. In that regard, Herbie's Tube Dampeners are also effective IME for reducing microphonics/bloat with nearly any tube.
Matching of small signal tubes is usually unnecessary (perhaps depending on the circuit they're being used in). I buy matched sets because it only costs a few bucks and it can't hurt, but its probably overkill - even in a $12K preamp.
As for the sound of one tube vs. another, that's too dependent on the equipment and the whole system for me to offer any opinion. I can describe what different tubes do in my preamp. I have little idea what they'd do in yours.
I do suggest you try new production tubes from the likes of JJ or Electro-Harmonix, assuming they make the types you need. Their performance can be strikingly good for far less money than many highly sought after NOS rarities. Don't buy into the snob appeal without trying the everyday stuff first - it may surprise you.
Some tubes have tall, thin vertical plates that look like a gentle breeze would tobble them over. Such tubes TEND to sound bloated, rosy or microphonic.
Other tubes have short, folded or even doubled plates that look sturdy enough to support an elephant. These tubes TEND to sound tighter, more neutral and less microphonic.
The above demonstrates the universal importance of controlling/reducing vibration and resonances in audio equipment of all kinds. In that regard, Herbie's Tube Dampeners are also effective IME for reducing microphonics/bloat with nearly any tube.
Matching of small signal tubes is usually unnecessary (perhaps depending on the circuit they're being used in). I buy matched sets because it only costs a few bucks and it can't hurt, but its probably overkill - even in a $12K preamp.
As for the sound of one tube vs. another, that's too dependent on the equipment and the whole system for me to offer any opinion. I can describe what different tubes do in my preamp. I have little idea what they'd do in yours.
I do suggest you try new production tubes from the likes of JJ or Electro-Harmonix, assuming they make the types you need. Their performance can be strikingly good for far less money than many highly sought after NOS rarities. Don't buy into the snob appeal without trying the everyday stuff first - it may surprise you.