I have an old Yamaha BB2000 that came out around the same time as the SG2000 guitar that Carlos Santana had a hand in. According to legend, Santana believed that the heavier the guitar - the better it sounded (or at least more sustain) ... so Yamaha put a heavy brass weight under the bridge. The weight is not fastened to the bridge - the weight is fastened to the body. The brass weight in the guitars is well known ... but I couldn't find any ads or reviews mentioning a brass block on the bass. Anyway - I pulled the bridge off my BB2000 and there is a heavy brass weight screwed into the body. I pulled the brass block out and weighed it - nearly half a pound. I played the bass for a bit and the only difference I notice is that the bass feels so much better on my shoulder I'm not saying there isn't a difference ... I'm just saying I couldn't hear or feel a difference other than the comfort of less weight.