recabling my Stax sr-009 to pure copper cable

Generally speaking, my experience has been that silver, being the second best conductor we can use besides gold, is one where silver will improve performance across the board on all levels. Initial 'tinniness' will always occur in cables with silver because I suppose it's some kind of chemical trait. This trait will give way later on after the cable has fully broken in, but this takes time. TRANSITIONING TO COPPER IS NOT RECOMMENDED because copper is completely inferior as a conductor. The 009s are known for a particularly sharp sounding signature, so I'd personally recommend either waiting longer until after the headset has broken in some by playing music on it for long periods as others have suggested or completely eliminating the problem by getting a tube energizer to fuel the cans. The latter is money restrictive, but would definitely provide a definitive solution. Whatever you choose, I would strongly recommend sticking to the silver cables, as Stax is one of the few companies that understands the value of good cabling on their products. There's a reason they don't allow interchangeable cables on their sets.