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

Several have made accurate observations.  However, too much talk about how loud.  What about how the Mahi Mahi sound?!  I've run them for years and tube rolled them to their pinnacle performance.  They've run Merlins, SA, Epos 11, Reference 3A and more.

The EL-84 is really fast and provides solid controlled bass.  These are about quality not quantity.  Acoustic bass is very well defined, vocals are open and instrument attack is immediate.

And besides, can we all not listen to well done production at a lower level?  Oft times volume is used to compensate for poorly done reproduction.  These allow for very satisfactory listening at sane levels and will not produce insane levels unless you pair with horns.

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.