Ah, to compress, or not to compress? That is the question. I confess, I'm not familiar with your Fostex, but compression may be an available effect, but is likely to be of so-so quality. Most people, I think, would recommend an outbard compressor. It's pretty much the RNC (really nice compressor) about $165-$175.
Look in the manual of the Fostex under outboard or external effects.
The bigger question is whether to use compression while tracking or do it later, at or before mixdown. The only simple answer is to use compression when you need to, to control the dynamics.
Compression is controlled by 4 parameters- Attack (how fast the compressor reacts), Release (how long the effect lasts)
Threshld (controls at what dB level compression kicks in), and ratio. Ratio is critical. At 3:1, for every 3 decibels above the threshold, you get 1 dB of gain.
Just get a compressor and play around with the parameters and listen, and watch the indicators. Beware!! Tracks overcompressed cannot generally be uncompressed. Yeah compression is like a vasectomy. You need to be really sure you need it.-Richie
