I have been wanting to try using a tube amp.

from hifi news lab test

"We weren’t quite able to confirm Focal’s claimed sensitivity for the Kanta No3 of 91dB, our pink noise and ’music’ figures of 89.9dB and 89.5dB SPL respectively for 2.83V at 1m suggesting that 1dB lower (or 90dB) is a more realistic figure. We’ve often seen Focal resort to low impedance to achieve high sensitivity from its speakers and it’s no different here. While quoting an 8ohm nominal impedance Focal admits to a minimum of 3ohm, suggesting rather a 4ohm nominal rating. We measured a slightly lower minimum of 2.9ohm and large impedance phase angles at low frequencies which together reduce the EPDR (equivalent peak dissipation resistance) to a punishing low of 1.2ohm at 82Hz. So the Kanta No3 is not a speaker to partner with amplifiers at all reticent about delivering high current."

sometimes people make posts about what tube amps can drive what speakers... and really don’t have the facts, nor a clue (scott and ralph excepted, of course... 🙏 )

Check out Ellington Hifi website. He has 2 used Octave Intgrated amps the 110 SE and V80SE. I heard i think it was the 110 driving some Dynaudio C60s and it manhandled them! Damn near half price on both. The V80 is the big dog. 

I agree with Atmasphere and that speaker is not well suited for tubes.  I have heard it driven well via a McIntosh MC275 but it was a pair that was bridged mono at 150w.  Not sure 200w is required but it is very clear the 20-30w you will get out of a Raven is not going to be adequate.  

There are not a lot of mid to high powered tube integrated amps and even fewer that can deliver decent power in Triode.  Most are ultralinear.  Something low risk like a Rogue Audio Cronus Magnum III might be an option for you as it will deliver 100w in ultralinear and will be in the same sort of price range.  

Another option would be a hybrid integrated with a tube input stage.  Something like a Rogue Pharaoh and find some killer NOS tubes like Mullard long plates to swap in.  This won't be as good, but will give you more of a tube presentation than a SS amp and delivers plenty of power to drive those at 175w into 8ohms.    
 

Looking at the speaker and its specs you'll need a pretty powerful amp, although a lot depends on your room. As far as I can make out (Focal is pretty precious about what specs they are willing to publish), this speaker is four ohms in the bass and 8 ohms in the mids and highs. They rate it at 8 ohms but dual woofers are involved, so the 8 ohms is probably due to the fact that the cabinet is ported, because those woofers are probably wired in parallel. I expect that is also why the impedance dip is around 3 ohms. This speaker is intended to be driven by a solid state amp. 


So you'll be using the 4 ohm tap on the amplifier, although you should try the 8 ohms tap too. With tube amplifiers the efficiency spec is easier to use than the sensitivity spec, because tube amplifiers do not double power as impedance is halved. Focal claims 91dB; converting to efficiency you get 89dB. In an average room in the US you'll need 200 watts to play any music at volume comfortably. If its a more lively room 100 watts will do alright.


You'll want to keep the amps close to the speakers if you can (monoblocks are good for this) and keep your speaker cables short, probably no more than 6 feet.


If you really want to see what tubes can do, a more efficient speaker and one of higher efficiency would allow the amp to better strut its stuff. Tube amplifier power is expensive to get right; this is why there are more efficient loudspeakers.

Go for it.  If you love sound there is nothing like the sound stage you get from a tube amplifier.  
I had the Nighthawk and Blackhawk and loved them.  
They should be able to drive your Kantas relatively high sensitivity.  

The speaker I will use with any tube amp I purchase are Focal Kanta 3.

@millercarbon [

Nighthawk is a pretty good step up from Blackhawk, it uses all their higher end caps.
]

I thought the Blackhawk was the step up model from the Nighthawk.

ralph aka atmasphere asked the critical question... what speakers?

really depends on that...

What loudspeakers are you running? This can have an big effect on the results you get from a tube amp. Generally speaking, a speaker that is 8 ohms or more (particularly in the bass region) and is of reasonable efficiency (+90dB) will show off the amplifier better!

Read the reviews, you will not be disappointed. Nighthawk is a pretty good step up from Blackhawk, it uses all their higher end caps. Also has a higher quality four step powder coat finish. Warm-up is no big deal, turn on when you get home, let it run however long. People who obsess over every hour as if their precious tubes are dying minute by minute are OCD. Besides, Raven, first 30 seconds stone cold sounds better than any ss amp. And it only gets better from there.

Incredible build quality. https://www.youtube.com/watch?v=Gcd76DZmbdY&t=302s

Raven offers a home test period.