Which amp with Wilson watt puppy 8

@ozzy as I mentioned above, I spoke to Jeff from Jeff Rowland (yeah the guy himself answered the phone !). He clearly said there was no problem with the electronics, blowing drivers at a certain amount of volume is normal, and advised me to keep the kids away. I wonder why hi fi constructors don t protect our expensive toys ? Bose outdoor speakers are self protected : I tried a pair of Bose 251 on my JR amp and at a certain level the sound suddenly faded. I thought I had grilled them like the sf but after a few minutes of cooling down they went back to normal. You can say what ever you want on Bose, but that is true engineering.  

... blowing drivers at a certain amount of volume is normal.

The magic word is "at a certain amount of volume."  Your SF Cremona could handle power up to 300w w/o clipping and is a nominal 4-ohm speaker with a factory-rated sensitivity of 90dB/2.83v/m (at 8-ohm). The drivers may not damage at the clipping power at burst but it may, especially tweeter, at a RMS power approaching its limit where the high freq. energy to which the tweeter is vulnerable.  Your JR continuum 250 is rated 250w at 8 ohm and doubled at 4 ohm load.  Let us assume your tweeters were damaged when pushed at 150w at 8-ohm when the amp is operated at the clipping power 300w at 4-ohm.

Now, into 4-ohm, the equivalent sensitivity becomes 90dB/2w/m (since P = V^2 / R = 2.83^2 / 4 = 2w).  Converting to 1W, the sensitivity rating becomes = 87dB/1w/m (= 90 + 10 log(1/2) = 87). 

Now, at 300w, the SPL = 87 + 10 log(300/1) = 111.8dB at 1m away. Assume your MLP is 3m away from the speakers.  At your listening position, the SPL = 111.8 - 10 log((3/1)^2) = 102.3dB (square distance rule).  

What sound level of 102.3dB we are talking about in real life.  A typical SPL inside the aircraft cabin during takeoff is approximately 105dB.  My question to you, OP, is that were you listening to music at a sound level comparable to sitting inside an aircraft cabin during takeoff when the tweeter blew out?  Your perceived sound level may not be very accurate, so I suggest using a smartphone app like Decibel X to measure it.

If I’m not mistaken the resistors in Wilson Audio speakers will melt and protect the drivers.
But I’m wondering why you are driving your speakers to such high DB levels? These speakers will handle high volume and powerful amps. But once the amp starts clipping you’re running a risk of frying the tweeters. Or in the case if Wildon, resistors. So either get a more powerful amp or don’t play your system at deafening levels or better yet do both. 

I spoke to Jeff from Jeff Rowland (yeah the guy himself answered the phone !). He clearly said there was no problem with the electronics, blowing drivers at a certain amount of volume is normal,

So it sounds like instead of blaming Sonus Faber for your woes, you are willing to accept the responsibility for what happened? Did I read that right?

Lotta opinions here but apparently little experience with your particular equipment.

I have owned Wilson W/P 7's 20+ years - very similar to series 8 - so maybe I can help?

The titanium tweeter in this vintage of Wilson's IS a little hot and not as refined as more modern drivers.  Despite this, these speakers still DO have merits at their current used values.

Not sure how well the Rowland amp you have matches the Wilson's.

I suggest trying a Pass Labs or, at lower cost, possibly a Parasound amp to drive the W/P 8's.  What you are looking for is lots of current drive and a smooth top end to balance that tweeter.

I use my W/P 7's in a third system so didn't want to break the bank driving them.  Ended up acquiring a used Parasound A21+.  Turns out there is great synergy with a smoother top end and enough drive and transparency to enjoy these vintage speakers.  I'm sure a Pass 250.8 would be even better but at double or triple the cost - so hey make your choice.

Remember the impedance curve of the W/P's dips to near 2 ohms below 100 hz, so the amp must be able to deliver lots of current.  Some amps have a high wattage rating but are NOT at their best into such loads.

Hope this helps.

Good luck!