I've never tried it, but what about a tube buffer, like the one made by Musical Fidelity?
I'd suggest giving Dakiom Feedback Stabilizers a shot as well, understanding that they can be returned and Dakiom will even pay shipping. Dakiom claims that "break-in" is primarily if not exclusively a psycho-acoustic phenomenon. I respectfully disagree, based on my own empiric experience with their product. I DO think the stabilizers break in after a while.
I'd suggest giving Dakiom Feedback Stabilizers a shot as well, understanding that they can be returned and Dakiom will even pay shipping. Dakiom claims that "break-in" is primarily if not exclusively a psycho-acoustic phenomenon. I respectfully disagree, based on my own empiric experience with their product. I DO think the stabilizers break in after a while.