Decware and SET Low Power Tube Amps with Hi Efficency Speakers

@larryi  .. fair enough, no one should just accept raving fan boys gushing about any gear. The OP did however ask about Decware's low-powered SET amps paired with high-efficiency speakers. Decware has been around for quite some time now and their amps have been well-reviewed with appropriate speakers. Neither their philosophy nor their products are everyone's cup of tea but they are well-built and have great value, certainly worth a 30-day trial for those wanting to go down this path. 

BTW, I've used supposed under-powered amps with a variety of very inefficient speakers with surprisingly good results. My Mark & Daniel Rubys with 82.5 sensitivity sounded great with a 25 wpc amp as long as I didn't push it too much. Same with my MMGs. As usual, it's system dependent and personal taste.

I tried both my little Zen and Mini Torii amps on my little Harbeth P3ESR’s. While the Zen actually drove them better than the Mini Torii did, both sounded exactly like Larry described. Not something that I think anyone would want to live with. As I mentioned before, you really want to be careful with the speakers that you match these up with and don't assume that they will work with every speaker no matter what the specs are.

I recently added a pair of Klipsch Heresy III speakers to my rig and their claimed 99db efficiency allows the use of very low power amps...2 to 3 watt SE stuff is popular with these things…so I assumed my Dennis Had SEP at 12 watts per side would work well, and it does, allowing "pre-distortion" levels far louder than I need. I have other speakers hanging around that have various levels of efficiency, and, of course, sound will emanate from them with any amp. But the fact that every little watt from the first one will provide sort of maximum detail in an efficient speaker seems like a good thing, and by being a proponent of this approach myself, I'm trapped in the efficient speaker zone…it sounds so good I don't mind really, but when reading reviews of any less than efficient speaker I now think…meh…trapped…I'm trapped...

I'm using a Grommes PHI-26 in pentode mode (6 wpc) on a pair of PMC FB1i's.  The PMC's are rated at 90 db sensitivity with a pretty steady 8 ohm impedance. 
Wow, color me shocked.  I originally picked this unit up for headphones but it excels with these speakers.  Outside of ultimate loudness I prefer it to my Ultraverve 3 preamp/VTL MB125 combo.

Grinnell.  question for you.  When you insert a headphone jack into your Grommes will it mute the speaker output?  Mine doesn't.

Thanks, Frank