[Diabolical Artificer]

How low distortion are you after? You can get 0.001 or lower with an opamp and lightbulb( wein bridge) , have the schematic if you want it, F is set by 2 R's & C's.

Here's some stuff I've collected over the years, inc JLH's, see attached. There's also an interesting thread, but a very lengthy read over on DiyAudio.

Andy.