Pass Aleph 30 vs. J

Why the 3?
The 30 has lower noise, greater dynamics, with better bass than the 3.
While the J has lower noise with a smoother presentation than the 30, but with softer dynamics like the 3.
The 30 is awesome and punchy.
The J is a 3 with a J-fet front end in a 30 chassis.

While I did own the 30, I've not heard the J. If you have high efficiency horns I seriously look into the J because it has lower noise and claims to be smoother from comments I've read. If you are using dynamic loudspeakers the 30 will give you better bass control.