HI John,
If you already did everything to the scott amp & it still sounds harsh or bright then here are osme more ideas:
1. I could be anothe rcomponent in th esystem (usually the speakers)
2. A tube or two may be bad
3. YOur hearing is sensitive to negative feedback or some such (you have GOLDEN ears)It would be very interesting to see the link on this amp in new zealand if you have it.
Sounds like it would be a lot pricier than any entry level amp.
thanx,
-akhilesh