Do you like to use AC filter or ISO transformer?

Hi folks, I'm curious whether you are using AC mains filter or isolation transformer for the digital gear. Do they always give better sound? In my case, I'm using a 1000VA Tamradio isolation transformer for the DAC with good results (fuller midrange, more air and detail, more analog sounding). The strange thing is: when using an isolation transformer for the CD-transport the sound is becoming too detached and some of the involvement is missing. Could you explain this phenomenon?

That's odd, to say the least. The only time I've ever heard of an Iso tran affecting sound negatively is when it was current limiting an amplifier. Since a source barely draws any current, that should be a probelm.

I use 4 industrial 2.4kVA Topaz Ultra-Isolators wired for balanced power(yields 1.2kVA). One for each amp and one for sources. Music is even more involving with the background noise gone, everything is much more vivid and bold. Seems like the seperation between notes is greater.
I use a double system: twin Auricaps (0.47 mF/600V) in parallel across the AC
receptacle and Topaz and Xentek (on its way) ultra-isolators on source and
preamp. Balanced power is an intriguing idea but already this setup gives
great results. Noise is much reduced, the soundstage spreads out in all
directions and becomes more layered, timbres become more accurate, tones
purer, digital artifacts less present, details cleaner, upper mids softer. In fact
after the iso treatment I can now listen to Alison Krauss--her soprano voice
can sound thin and hard without it.

An iso tranny on my DAC (an Apogee DA-1000E) doesn't do very much for it
and neither do premium power cords. I presume the unit's outboard power
supply already does a great job. However a tranny works very well on the CD

Dazzdax, what you say about detached sound reminds me of the first time I
connected my preamp to an isolator. I had the impression that things had
become more laid back and colder, but after listening for a while I realized
the music was not colder but cleaner. I could relax more and let the music do
its thing to me, I didn't have to put in as much of my own effort to be
involved. Maybe this is not what you meant, though.

Iso transformers are IMO a terrific tweak, providing a sonic improvement in
some cases akin to that of a new component, or certainly a cable upgrade, for
generally a lot less money. Digital sources I had not wanted to listen to have
become pleasant once a transformer and some isolation feet were added. The
transformer doesn't have to be of ultra quality, a cheap Triad can work very
well, and sources from entry-level to high end can all benefit.