power conditioner for cd transport and dac?

I think it is recommended by at least some experts to use separate power conditioners for digital and analogue to keep the digital noise out of the analogue power source. It is even recommended by some to use separate circuits for analogue and digital. Some higher end power conditioners have a dedicated digital input. I just use two cheap ones--one for analogue and one for digital.

I use isolation transformers on my digital front end gear. That is where I have found a transformer to have the most effect. Perhaps this is because, besides removing noise from the AC to the gear, they also isolate the digital gear from the rest of the system.

my experience has been that digital is the area that most benefits from power conditioning.

I'd recommend getting and installing a Porter Port or Maestro or TelslaPlex and plugging your DAC directly into the wall without conditioning. Experiment with various power cords (give them time to settle in, don't A-B them back and forth like a switch... PCs need to settle down). Power cords make a huge difference on DAC sources. Doing so has made a huge difference on my system. In fact, on my most high res system, I have entirely eliminated the use of power conditioners. Careful selection of the right power cords has made all of the difference with PorterPorts and Maestros. IMHO, lots of money goes into power conditioners that is better spent elsewhere, such as a dedicated power line to the system components, e.g. isolate the digital sources with a separate line.

Just my opinion and experience (YMMV),

:) listening,

Ed