What does a high end cd transport, a high end DAC, and a high end amp do to the electrical signal traveling in decent speaker cable to make good speakers sound better? What do you get for the extra money? I know that electricity does not care about money spent and so called snake oil. Assuming amp wattage is the same, what in the electricity traveling down a 99.9 oxygen free wire is different with expensive equipment? Can any engineers or just smart people explain this to me?
Better DACs are not a bad thing to have. These are typically what you will find in better AV receivers, or better transports. Or in a better DAC. The analog conversion process, and then the protection of that analog signal is still one of the most difficult and negative parts of the digital process. Speakers are still analog, so when that digital conversion takes place it needs to be considered how good, or great, you want that conversion to be, and what that is worth to you.
It is incredibly wasteful to buy a high end CD player with an incredible DAC in it, and highly protected analog section, then just run digital audio out of it into a different high end DAC. You are just duplicating the setup.
A high end amp may be completely different. I'm not sure if you just mean 'expensive', or if you actually mean 'high end'. Over the years I've seen dozens of amplifiers fail. They blow channels. Some have been VERY expensive, others have been cheap. But, when I think of the term high end, I think of a product that is actually capable of delivering the power it states, across all the channels it has available, at the same time, without failure. A high end amp, to me, has incredibly high reliability, and delivers flat power across the entire audio spectrum without weak areas. Early Class-D amps, if I remember correctly, were not able to deliver clean power across all frequencies and would not always sound good.
It's not like your amplifier just takes power from your wall and just sends it to your speakers directly. You can't plug your 8 ohm speakers into your wall and suddenly have music. You need an amplifier somewhere in the mix. And if they actually are 'good' speakers, then they may benefit from having a amplifier that is designed to deliver them clean power. In higher end models, they will likely have balanced audio inputs... WHY? To protect that analog audio and deliver the cleanest possible audio to the speakers in the room.
Keep in mind... It's all about scale. If you consider a $1,500 surround system 'high end', then I expect it is money wasted. If you have $5,000+ in speakers, then it will start making more and more sense to consider a dedicated amplifier to drive them. And to ensure the audio is as clean as possible along that pathway. But, high end doesn't necessarily mean expensive, but there is a TON of that out there as well.
