Loose,
Interestingly and not surprisingly, the advice so far is all over the map. I am usually a source-first guy, but thinking in this case your older amp may be the greatest factor. New budget CD players from Cambridge, Music Hall and NAD are getting much better, and the suggestions to demo other gear and cables if you can is helpful. While thinking about wires don't ignore the possibility of trying aftermarket power cables if your gear have detachable power cords. Again, you don't have to spend bundle to hear real benefits from a thicker gauge and well designed and constructed cable, shielded for CDP and unshielded for an amp.
While you are trying to sort these larger things out, here is a cheap trick you can try that wont cost an arm and a leg, and I have found opens up the sound of my system and brings out the highs and details - especially when applied to my CD player.
Buy a length of hardwood - say a 2" X 2" oak replacement leg for a coffee table, $8 or less. Cut it into a series of perfectly flat 2x2 chunks in groups of three or four of the same height that can be used to raise your CDP or amp about 1/8" above their stock feet. Experiment on suspending your amp and CDP on a set of these on your rack. I would start with three, one under the transformer and two others placed to complete a stable triangular base.
The dense wood will serve to transfer vibration from your gear to the rack more efficiently than stock feet that usually have rubber pads that isolate and trap internal vibration in your gear. If your rack is made of a material that can absorb and dissipate the vibration from your gear while also effectively isolating it from vibration in the room, you will likely experience the greatest benefits from this trick. This accomplishes some of the same benefits as brass cones and other isolation devices at a fraction of the cost.
If your rack system is suspect in either respect you can place a heavy block of wood, like a maple chopping block, directly under your gear and the small wooden blocks to carry out some of the same functions described above for your rack.
Other relatively cheap tricks include using a contact cleaner and silver treatment on the connectors for your speaker and interconnect cables.
Moving up the tweak list a bit, many people including me find that replacing stock fuses in electronic gear with silver fuses has a positive impact on sound quality.
The above tricks can be accomplished for relatively small investments in time and money, and while usually not offering the same level of benefits as wire and gear changes, will nevertheless push your system in direction of the "more open, airy and extended sound" you seek.
