My thoughts on the grounding block:
Impedance is the resistance occurring in AC circuits. The lower the impedance the easier it is for electricity to flow. Impedance is found not only on the positive and neutral legs of the AC but also in the ground conductor portion of the circuit.
There are voltages even in ground circuits. These voltages will cause current to flow. The purpose of the grounding block is to cause maximum current flow through the connectors conducted to it. When this happens noise in the ground currents are shunted to earth ground and away from other components in the system. This has the effect of lowering the noise floor of the entire system, allowing information, previously buried by noise
to rise up and be heard. (only the head of a 6 foot tall man standing in in a swimming pool 5 feet deep can be seen. But, if you lower the water level to 4 feet deep, you will be able to all of him from from the waist up) Similarly.
the lower the noise floor in your system, the more musical information you will hear.
The reason for the massive increase in fidelity you heard when you connected your home-made silver cables, is that your cables have lower impedance than those that came with the grounding block. The circuit did not change. Only the cables changed.
I have experienced everything you mentioned in your initial post. Moreover I had ordered one High Definition cable ($375) and one standard definition cable ($100) with my grounding block. This allowed me to build my own cables and compare them to the Synergistic cables. I feel comfortable saying that your home built cables should equal the performance of the Synergistic HD cable and far exceed the performance of the standard
definition cable. (The standard definition cable should not be confused with the thin black wires that came with the block. It is made of silver wire and a decent quality RCA connector.) I now have three high definition cables in my system. One to the wall, one to my SACD source and one to the pre-amp.
The grounding block has elevated the performance of both our systems beyond beliefs. Thanks for starting this thread.