Basses are fine, nothing wrong with the sound of the Ashdown combo, I’d just look at a more powerful one - the Ashdown RM combos def worth a look at if you like the Ashdown sound, or look for one of their MAG combos 2nd hand - you’ll pick one up within budget easily. That said, you can pick up an Ashdown 500 watt amp head and 410 cab used with a £600 budget.