Hi Kev
Well, where to start! I have this pre on my custom fretless and one on order for my new ACG fretted beastie. It requires a slightly different approach to 'normal' EQ systems. The volume blend stack needs no expanantion, and presumably you've got the hang of the tone knob (active & passive). It's the middle three stacks where the interesting stuff happens.
I can't say which setting 'represents which typical bass tone, but the way I approach the set up is to wind the blend fully over to, say, the neck pickup. Set the top knob on the neck filter stack to the centre and then play an open string and then turn the bottom ring control and listen to the effect it has on the output. You are basically adjusting a low pass filter to set the frequency at which the filter operates. If you turn it back and forwards you get a wah effect (if that helps). The top control works on the boost at the knee point of the filter plus it has a pull function for low mid boost. Play a few well know riffs and adjust to see the effect and to find the tone you like.
Once your happy with the this, crank the blend to the neck pickup and repeat. You can then use the blend knob to change the way the bass sounds. If you have two different settings on these two stacks and you can go from a deep double bass type thump to a very bright tone with one turn of the blend control.
The treble stack is a different beast, and takes a bit more work to get the best out of it. It is basically a high pass filter that once again you can adjust the knee point and the top knob in this case is pure gain from zero to ??? can't remember +dBs.
Take you time to work your way through it and my advice would be to not change everything at the same time as you can get 'lost' quite quickly. There are links at the bottom of this page which take to an explanation of the EQ03 too: [url="http://www.acguitars.co.uk/acg_admin/wordpress/basses/electronics/"]http://www.acguitars...es/electronics/[/url]
...and here: [url="http://www.acguitars.co.uk/acg_admin/wordpress/pdf/ACG_EQ03.pdf"]http://www.acguitars...df/ACG_EQ03.pdf[/url]
If you'd like to chat about it please send me a PM and we can organise - more than happy to help as it can be a bit weird if you're used to 2-band and 3-band EQs.