Variac vs. Isolation vs. Balanced Transformer? ALL

Jea48, after posting I did some research and found out that ANSI Standard C84.1 covers residential voltage regulation in North America and that the limits are ± 5 percent of 120V.

My Results:
Okay so the Balanced transformer does not seem like a bad thing! Meaning for the little I got to test listen it did not seem to remove anything from the music or overall dynamic presentation, however what it did do was remove a slight amount of "Anxiety" maybe in the presentation… Seems to have very slightly laid back the soundstage where it moved backwards about a foot and became about a foot wider, might have a little better balance from left to right so to speak.

Vocals have a bit of a more left right quality of being less accurate and more blended with air, the bass is VERY tight, it may have literally made the low frequencys lose a little of the Bloat and more of a dynamic yet buttery type punch, more cushion if that makes sense. There is not a final verdict, but its pretty cool! Worth the money?

Very tuff to justify something like this one way or the other, its worth it due to knowing it has an effect to the AC power in the house whether its gonna be detrimental or beneficial depends on a lot of things… In this case I would say I give it a 5% effective rate, that means a bit better control and distortion is minimized even further, for 5% at this level it costs money because there is very little you can do to make perfection, and this system was damn good already so just a little bit is nice but maybe not gonna make miracles..

For the time being I am of course happy with it, I like having it, and it does solve one Ergonomic problem that is not a big deal but being picky, it gives me ONE power switch to turn on and off the amps without opening 3 doors on my unit everytime! Anyway and of course the pride of ownership, and I upgraded the CRAP out of it last night removing the ground shunt capacitor pack setup in it to the AC recepticals, and put in buss bars replacing the cheap terminal strips… I am told these ground shunt filters are great for eliminating common mode noise but can end up being a downside to audio applications robbing you of some dynamics and they are somewhat dangerous if they fail and you don't have a GFI outlet connected to it… From what I am told these shunt filters if one cap fails and there is no GFI outlet your done.

I posted a similar question about 6 months ago on Audiogon, in reference to a high voltage problem I have at my location. I have been using an older tube amp that was not designed to run on higher voltages, and my lines are giving me a pretty consistent 124 volts. The voltages inside my amp run beyond the ratings on power supply caps. and other components, which can cause premature failures.
I needed to reduce my line voltage in order to extend the life of the amp, and tried a variac as the first affordable solution. I tried a good quality 10 amp unit, but unfortunately, it degraded the sound. I did not have the budget for some of the more expensive $1000+ line conditioners that could also regulate voltage, so I tried the following suggestion I had from a fellow Audiogon member: http://www.geocities.com/jonrisch/catch2.htm
It is a D.I.Y. high current transformer that can reduce output voltage AND be configured to output balanced power as well. It is a Signal DU-2 transformer, which can be purchased new for a bit over $300. I got mine on the used market for under $100 (E-Bay). I made my own enclosure for it, and wired it with a high quality AC outlet and power cord to the wall. I am now getting a constant 113 Volts for my tube amp, with the benefits of cleaner, balanced power. It works like a charm, and throws off very little heat and no hum. After re-biasing my tube amp for the lower voltage it puts out, it sounds fantastic with no loss of dynamics, and with a slightly deeper and more detailed soundstage. My amp runs cooler and all the new power supply caps, signal caps and other components installed from a recent re-build should last for decades.... Problem solved, and for well under $150!

Bigshutterbug, I believe it! As I stated above most audio gear regardless of its "designed voltaged range" will perform better the closer you get it to 110 volt side of things opposed to the high 120 and above in my experience.. Some don't understand it, or don't want to believe it, but it does work. By the way what is the exact make and model of the transformer you purchased? Do you have a diagram to configure it to lower voltage and balanced operation? I have seen the website and this project you refer too, I saw it was from like 1999, not that the year makes a difference, but anyway what size is the transformer? 500 va, 1000 va? Thanks

And again remember this kinda very specific and really major foundation stuff of an audio system in most peoples minds that get done last!! Room acoustics, and the power feeding your system is totally overlooked and probably accounts for 75% better results than a 1000 dollar preamp to a 10,000 dollar preamp.

Yes, a dedicated line is the first step, a good outlet, properly treated room, and correct speaker placement are often the least costly "tweaks" that all add up.
I am using the Signal DU-2 transformer. It is rated at 2Kv and 18 amps as an isolation transformer, and about half that when wired to produce balanced power. Mine ran warm and made an audible hum when wired as an isolation transformer. I did not notice any gains in sound quality running the amp through it this way, but it did reduce the voltage. When I wired it balanced, it runs extremely cool with no audible hum. There was a noticeable change for the better in detail and soundstage, but it was not not quite as dramatic as my previous BPT 3.5 Ultra power conditioner I was running. It sure was a LOT less money though, and my tube amp should last me a long time.
I can send you a diagram showing how to wire it if needed. It is not as difficult as you would think. It only took me an hour or so...