I am using a Barcus Berry 300A pickup and I'm having real problems with getting a decent volume out of it in gigs. I am in an electronic band which uses electronic sub bass and various other whizzes and beeps of different desciptions.
I play through Trace Elliot 300W amp which is fine for my Bass guitar - more than fine in fact. But everytime I try to turn up I get horrible feedback. I have tried every combination on setup, from having the pickup preamp up high and the amp low and vice versa, I have tried making it more trebley, less trebley... everything! But still feedback.
Is there something I can do with my current setup? or should I go for a different pickup - if so which one?

I've emailed you directly, through TalkBass, with a text extract from the insert I supply with every bass pickup and preamp I sell. It deals with feedback issues and how to avoid it.

I'll also gently point you towards the K&K Bass Max:
http://www.gollihur.com/kkbass/bassmax.html
as a pickup that has good sound and high gain before feedback. Disclaimer: I sell 'em, so feel free to suspect my motives.

But not my advice about feedback ;-)

Try a K&K Bass Master Pro w/pre-amp, a good EQ, and some different speaker configurations.
I bought a K&K system from Bob Gollihur and it is so much better than the Fishman pickup I had. (Thanks Bob).
I get GREAT TONE & VOLUME!!!
I backed off some of the bass on my amp, and boosted the treble. The sound is distinct and crisp.
I play in a 5 piece jump-blues band playing concerts, festivals, parties, clubs, etc.
Sometimes I really need the extra volume, the only way I got it, was to switch to the K&K.
Good luck!

Another vote for the K&K Bassmax from a happy customer.

K&K Bass master Pro is the way to go.

`NUFF SAID! K&K does it for me too.

I use a Barbera, and I can get some pretty high levels in a rockabilly band I sometimes play in.