I recently swapped the tailpiece on my chinese plywood, from aluminum to ebony. The results overall were good. But when swapped the same ebony one with the one on my new fully carved speyer 606s 3/4 size (rosewood tailpiece) the results were interesting to say the least. I simply thought it would increase sustain, looks etc. The results were similar to when used on the plywood, but with the bad side effects far more pronounced. Although volume and sustain has generally increased, It has created uneveness of volume and tone across all strings (louder<D-G-E-A>quieter) The A in perticular has taken on a thin, split up sound with a wolftone like harmonic overtop of the weak intitial note. My question is: Does tailgut length or material used play a role here? or is it just the density and/or harmonic resonance of the woods used for the tailpeice? or both? or something else I can't think of? I do have luthiery skills in the slab bass department, but upright is just a whole nutha gig. I am playing on thomastik superflexies, 60% pizz- 40%arco. This is my first post, so any support here is much apreciated, thanks.