Anyone use 100v or 220v gear with a transformer?

I've heard several pieces with transformers over the years. I recently had a Reimyo CD player and a Airtight preamp that was 100V. Both were sold after I heard my friends 117v Airtight in comparison. Both had the same tubes and it was in the same system. The dynamics in particular were much better without the transformer. The transformer was a 2000 watt unit which had won out in comparison to a few others I tried. Its not a small difference. Why do you think manufacturers go through so much trouble to design a power transformer?
Thanks for the welcome. I don't normally post but this topic was fresh in my experience.
I'm often amazed how much time people devote to forum posting rather than music listening. Tonight I'm forced to keep my system off- my girlfriend is studying.

+++ a transformer will absolutely diminish performance +++

That is patently untrue. Given the correct isolation transformer, it will dramatically improve your sound, especially if you live in apartment complex where the mains are very dirty. Isolation transformers can drop noise floor by 6 to 12 db.

Folks like BPT don't have thriving business because their products detract from sound.

I guess you are the lucky one – enjoy your iPod.

Regards
Pauly

Interesting and informative answers from everyone. Most agree (including the manufacturer's Japanese representative) that a step down transformer can be used without problem.

The issue of sonics is the quagmire. Other than the mention of degraded sonics here, the only other mention of this has been from a US dealer. Clearly, there could be an agenda with the dealer, but I also am not willing to dismiss the possibility of degradation.

I have decided to forego purchasing the Japanese unit.

I have decided to forego purchasing the Japanese unit.

Sorry to hear you have been frightened away from your plan. I agree with Pauly that bigger is better. Most Transformer cores saturate when used close to their rated power and that is when you get annoying humming from DC offsets and potential degradation in the quality of the power.

I am actually quite surprised that the Japanese unit will not function with 120 Volts if it is rated at 100. I would have expected the Japanese device would tolerate the slightly higher voltage. (Nominal power is allowed to vary about 5% from your utility and devices are normally designed to function properly a further 3% to 5% outside this range (due to further voltage drop in the home). I would expect a similar kind of tolerance for Japanese equipment.

Signal degradation is very unlikely.

The ability of the 100v unit to function on 110-120v either straight to the wall or with a step-down transformer was not the issue. Sonic degradation was an issue, as was safety and warranty service, which would have required shipping the unit to Japan for service if it was required.

I spoke with someone today who is intimately involved with tube gear, and who has no agenda whatsoever, and his advice was to buy the 120v USA version.

I'll have to admit, it was difficult passing up the opportunity to buy the Japanese model for 45% less than the US version with 120v transformers (and nothing else different), and because of the large price differential I will likely explore other integrated amplifiers.