I have a Monarchy SM-70 Pro, which is all class A like your Forte 4a, along with Von Schweikert VR-1s, so our setups are similar. I'm partial to 6SN7 preamps, so here's one possibility in your price range:
http://cls.audiogon.com/cgi-bin/cls.pl?preatube&1139600670
If you can stretch your budget a little, there are also a Wright WLA12A and a Mapletree 5B for sale right now; I have no connection with any of these sellers.
I own the Wright, and it's a sweet combination. None of these have phono, though.
http://cls.audiogon.com/cgi-bin/cls.pl?preatube&1139600670
If you can stretch your budget a little, there are also a Wright WLA12A and a Mapletree 5B for sale right now; I have no connection with any of these sellers.
I own the Wright, and it's a sweet combination. None of these have phono, though.