Your experience is similar to mine. I started with Pods under my turntable thinking that would be the biggest, and was surprised when the impact on my integrated tube amp was at least as big. With the turntable most of the improvement was eliminating resonance that was coloring instruments, and lowering the noise floor. With the amp it did the same but the biggest improvement was dynamics and a midrange/top end that was a lot more clean and clear and detailed. Similar to what you had, less ringing made the top end clean and clearer than ever.
Podiums were put off for last, just found it hard to believe anything could really be worth that much money. Didn't take long hearing them to know they are worth every penny.
The Townshend F1 cables by the way have a lot of the same effect. Pods eliminate physical ringing, F1 cables eliminate electronic ringing caused by impedance mismatch. Totally different mechanism, very similar result.
Happy hunting! ;)