Have you heard of theĀ Intona USB cable?
It seems to be relatively new and is made by the same German company that makes the Intona USB Hi Speed Islolator.
I can't vouch for it but it looks promising and is cheaper than what you've tried so far.
All the best,
Nonoise
It seems to be relatively new and is made by the same German company that makes the Intona USB Hi Speed Islolator.
I can't vouch for it but it looks promising and is cheaper than what you've tried so far.
All the best,
Nonoise