Raoulduke,
Here is a quote from Doug about the gain controls...
I see a lot of FR-2 users who set the front panel record knob to 7. This kills 12 dB of gain thereby raising the noise floor. It is a bad idea, try running at 8, this still gives you 6 dB of level that can be applied from the front panel level control and gives you 6dB better SN ratio on the downstream side of the front panel attenuator. The front panel control is NOT a gain control, the only gain controls are the input trim knobs on the top of the deck. I bypassed the front panel control and the HPF/Limiter in my FR-2 and it sounds better. I set levels with the input gain controls. You can get closer to that and for free just by running your FR-2 as close to 10 on the front panel level control as possible.
Peace and good sound...Doug