The F609 is a professional tube microphone preamplifier, using two double-triodes, one ECC802S (12AU7) and one ECC803S (12AX7), in a single 500 series rack module. It provides an +160V power-supply to avoid starving the tubes. The F609 uses high quality American made input and output transformers.
The main feature of the F609 is the combination of the Input Gain knob (0 to +70 dB) plus Output Gain Knob, plus all-tube signal path. The output level control allows to change the characteristic of the amp and to run the first stages all the way up to distortion and it is genuine old-school tube distortion. The sound is very smooth with a big, well defined low-end. This little module can rock with the best of them.
The F609 is particulary interesting paired with the F602 tube compressor, if you happen to like high end vintage flavors and genuine tube character. It also pairs nicely with the Artistic Compressor and Artistic Leveller for traditional 70's style tube mic-pre into solid state FET or Opto compressor chains. Some engineers chain all three.
Additional features are: 20db Pad, polarity control, phantom power, a two stage low-cut filter, and a standby mode to preserve the tubes if not in use. The traditional VU meter is standard.
Not all racks can supply the 250 mA that the F609 requires, but any of the Bento series are well suited to provide that.