JFET drives most definitely have some magic. Maybe someone more technical can chime in and explain their non-linearities and clipiping characteristics. I think it's safe to say that they can emulate tubes better than any other solid-state devices.
Some things to consider:
- JFET's have a limit of how much gain they can deliver.
- Most JFET designs rely on J201's, which are in short supply, to get enough gain.
- Amp Emulators that use JFETs (Catalinbread stuff, RoG stuff) often use cascading gain stages which typically raises the noise floor quite a bit, even when you set the gain low.
- It seems like most people prefer JFET circuits based off simple tube preamps. These usually don't have a ton of gain but impart a little bit of a magical essence (everyone uses different descriptors).
- Running JFET circuits at 18V is the easiest way to squeeze out more gain, but requires rebiasing.
