25 Watt Tube Amp for 90db Speakers?

Viridian's got it. The size of your room, how lively it is and your own listening habits will say whether that amp is enough power.

If you don't have a large room, it's fine. Vintage HH-Scott which is 22wpc apperently can do better job for less money in great condition for your further consideration.

Quicksilver mini mono's , nice mono block 25watt amps!

In addition to the variables that have been cited by the others, I would emphasize the relevance to your question of the kinds of music you listen to, and particularly their dynamic range. Meaning the DIFFERENCE in volume between the loudest notes and the softest notes.

Quoting from myself in a past thread:

I'd just like to suggest that you indicate to the assembled multitude what kinds of music you listen to.... It is not uncommon, for example, for well engineered classical symphonic recordings to reach brief volume peaks that are 30 db or more greater than their average volume, and 40 to 50 db or more greater than the volume of their softest notes. A 30 db ratio of peak to average volume levels means that you will need 1,000 times as much power for volume peaks compared to the average levels of those recordings. And a 50 db difference between the loudest and softest notes requires 100,000 times as much power for the loudest notes as compared to the softest notes.

Many and probably most rock recordings, on the other hand, are compressed to a dynamic range that is in single digits as expressed in db, meaning less than 10 times as much power is required for volume peaks as compared to the softest notes.

Perhaps differences in the kinds of music that are listened to by those who have posted contribute to the divergence of opinion.

I can tell you that in the past I have used 90 db/1w/1m speakers having fairly easy to drive impedance characteristics with a multitude of tube and solid state amplifiers, of widely varying power ratings, listened to from a 12 foot distance in a 13 x 22 foot room. 25 watts was certainly adequate for most recordings, but 200 watts was barely enough to handle brief dynamic peaks on some classical symphonic recordings having particularly wide dynamic range.

Regards,
-- Al