I think Fender has lost its mojo as far as bass amps are concerned. I had a 70s era Bassman with a 2-15 cabinet, and although it was underpowered and larger by todays standards, it had delicious tone.
Todays fender BASS amps are blah...
There are some semi botique brands I listed, but to be honest, a Peavey is LOUD, had decent tone, and rugged as heck.Shoot Ive seen duct taped peaveys with half the knobs broken or missing and they keep chugging the bottom end.
I am sorry I am not familiar with the Black Line Amps.