My buddy brought in his '64 blonde bassman so we could comapre them. We played through the same vintage '62 cab with Jensen P12Ns. His has a wonderful bloom, depth, and detail that's lacking from mine. It almost has a tweed vibe to it. At first we thought it was the tubes but after swapping them around, the results were the same. We flipped them over and the circuits are the same. All original parts except for the electrolytic bypass caps. All of the filter caps on mine were swapped out for Spragues. He has two filter caps swapped and replaced with 200uf which seems pretty high. If anything I thought that would result in a stiffer tone. But it's just the opposite of what I hear with mine. What gives? Component value drift? Anything else?