Speaker wants 100 watt RMS. Is 40 watt tube OK?


I’m considering changing form parasound a21 to Manley Mahi monoblocks (40 watt tube) to go with my Monitor Audio gold 300s.

the speakers (90 dB sensitivity) say they want minimum 100 wpc.  

What kind of problems (any?) will I run into?
otherones
I really appreciate all of the discussion. My local store let me borrow the Mahi Mahi over the weekend and I spend a good amount of time playing with it and swapping back and forth to the Parasound A21. For additional context, my Preamp + Phono is also a Manley (Steelhead).

The room I am in is pretty small and the speaks only 8ft or so from listening position. I did not have any problems getting good performance out the power of the Mahis.... even in Triode mode things sounded great. UL bumped up the power but I suspect for most of my listening (jazz and acoustic vinyl) I’ll be playing in Triode.

At the end of the trial, I’ve decided to keep the Mahi Mahis and will end up selling him A21s at some point. Not sure if the Manley Steelhead being of the same manufacturer is part of it but the combo is sweet.



Now it's my time to crow; everything is just like I said, "Tube watts are louder than SS watts, plus they sound better"

Also, the room is the dominant factor; unless you got a huge room, you don't need all them watts.

When I'm right, I let everybody know it; but most importantly, we have another contented audiophile.
I rest my case.  Mahi Mahi mono blocks are so good.  And Manley Labs is correct.....Tubes Rule!  Never had a doubt.  Now you can play the tube rolling game with Upscale Audio.  

It is mind blowing how different these amps sound with tube and power cord upgrades.  I run Patrick Cullen.  You may like others.  The timbre, resolution and attack of the amps will change appropriately with upgrades.

The Steelhead is great and voiced well for the Mahi, but you may not need to go beyond the Jumbo Shrimp (no phono).  That was my match up until the Manley Neo Classic 300B with Takatsuki 300B tubes.  Enjoy the ride.  

You have done well grasshopper.
Orpheus10 , you are right. Tubes gives a louder sound, but more correct. When the tube-amp is 40 W, than he gives constantly 40 W. I had a Copland 405 tubes (25w) ,with the Audio Monitor PL 300 (350w): In a room of 55m2. It sounded incredibly beautiful. You gonna enjoy it!!!!  When you play exactly 10 W in your room ,after an hour ,  you go walk in the park ,because it’s very loud