Devialet for Wilson Audio Sasha 2 Speakers

@georgehifi 
As far as I know Nelson doesn't design anything with BJT outputs. I'm almost certain BJTs aren't the output devices because they don't tolerate being biased up to a full amp well at all. Beyond that, they have poor slew rates compared to FETs and he believes in high bandwidth. I'm quite sure it uses MOSFETs. I don't think he had a suitable supply of the big JFETs he likes to design with lately when the INT-60 was designed. I seriously doubt the numbers of MOSFETs in the INT-60 pose any current limitations. I'm listening to some Bassnectar through an F5 running very hot rails and no current limiting, powering a pair of Focals, and if there's some limit to the current those 4 little MOSFETs will push, I'm not FEELING it. I think this F5 is the best amp I've ever heard. If the INT-60 is anything like it, I'd snatch it right up. 

As far as I know Nelson doesn't design anything with BJT outputs.

Suggest you look at nearly all the bigger Thresholds amongst others he designed.

Cheers George 

@georgehifi 
"Doesn't" is a present tense term. Threshold gear is hardly "modern era" stuff. Nothing that's come out of Pass Labs or First Watt features BJT outputs or inputs. Everything from Pass Labs and First Watt uses MOSFET, JFET, or SIT output devices. 

Even so this sort of impedance and -phase angle load that the Sasha presents in the bass needs a lot of current to drive, and BJT’s do that better than Mosfets can.
https://www.stereophile.com/images/archivesart/710Wilfig1.jpg

Cheers George

I get it, but I have no idea where you get this idea a huge bank of FETs don't get the job done. I'm listening to an F5 I built right now and the whole reason Nelson designed it with 3 way current limiting is because those MOSFETs will switch the full power supply current in tiny fractions of a second. My Focals aren't as brutal as those Wilsons, but with a low point of 2.8 ohm and a -56° phase angle at 4 ohm, these will draw some current. This F5 drives them with absolute ease. If it struggled at all I'd be seeing serious rises in output device temperature which isn't happening. I see maybe a 5°C rise under the most taxing volume and material. I have no doubt an INT-60 would have just as easy a time with the Wilsons.