tube vs SS preamp

There is very little danger of a tube preamp failure causing a large signal that would take out a speaker, particularly when the downstream amp is a low to medium powered tube amp. Damage is more likely with a solid state amp, particularly higher powered amps.

Tube linestages can be a bit more prone to non-life threatening noise issues than a solid state linestage, but, most of such issues can be cured rather easily by changing noisy tubes. As far as life expectancy is concerned, this is largely a matter of the design of the linestage. Most small signal tubes used in linestages have long expected lives and are usually run conservatively and will last a long time. However, there are some designs, such as those by Counterpoint and Audible Illusions that were run somewhat hot and needed relatively frequent tube changes.

I generally prefer an all-tube setup to one that is a hybrid. But, I have run solid state into tubes with pretty decent results. I have generally found the alternative hybrid setup--tube linestage into solid state amp--to be less predictable and consistent in result; it can work, but, there is a greater chance of the combination being a disappointment.

IT can happen anytime.

Amp will amplify whatever it is fed unless protection circuitry kicks in.

Tubes can have various issues. So can transistors. But tubes probably more often.

End result will vary case by case depending on circumstance and design.

So tubes are riskier, but not a big problem normally in well designed gear and with good quality tubes.

Thank You for explaining folks. I have NEVER been in the tubeland. At this point I am seriously considering upgrading my preamp to the Parasound JC-2, because my amp is also Parasoud, and I have heard nothing but good stuff about the combo.
But for the past week, I have been trying to read up on tubed preamps. Still I hesitate to venture into that area because I have no idea about installing, biasing, maintaining tubed components. I will look up more before settling down for a good preamp upgrade.

Milpai, tube preamps (unlike tube power amps) require no biasing when tube changes are needed. If the tubes get noisy you can easily replace them, the old ones are lifted out and the new ones just slide in. Generally speaking the low level tubes used in preamps can last for years without needing replacement, but of course an early tube failure is always a possibility.