Step Up/Down Transformers - Good or Bad?

I have an amplifier that was purchased in Europe and I am using it here in the States. I am having to use a step up transformer in order to connect between the wall and the amplifier. Is there a compromise to the sound with any transformer that is placed between component and wall outlet? Does it all depend on the quality of the transformer? Can one use an after-market power cord and have it yield benefits, even if it is plugged into the transformer?

Appreciate the responses.
If is possible the amp has multiple taps on the transformer with one being
120V which you could switch to for use in the States. It would help those on the chat who may be able help you ,if we knew what amp you have.
Sorry for the bad post with typos , etc.
Glrtrgi, If you are going to live in the States for an extended period of time it might be worth having an electrician install a 240 volt line for your Euro amps.

USA homes already have 240 volt but typically limited to power electric cook range, clothes dryers and heater-furnace.

I've successfully used a pair of 240 volt runs in my stereo system for more than a decade with no issues.
No major issues with amps. You must get a large enough transformer however or you will suffer. For a Power Amp expect a transformer to be roughly the size of a 5 Lb bag of sugar.
I think Albert has the best solution. You should however remember that the power company uses various step down transformers before it gets to your house. Thus there should be no real problem.
It is an improvement rather than a problem from an incoming power quality perspective, as long as it is not undersized. Some of the audio power conditioners sold for significant $'s are not much more than a 1-1 transformer in a fancy enclosure (fwiw, installing a regulating transformer in front of sensitive electronic equipment is common practice in industry). Sola, and others, make a good regulating transformer at a reasonable price if you wish to get fancy. The 240v line solution works, but kids tend to stick things in outlets at some point in their life & the penalty for doing this can be much higher. Good luck!
The 240v line solution works, but kids tend to stick things in outlets at some point in their life & the penalty for doing this can be much higher. Good luck!

Remember that 240V in USA is twin 120 volt runs. This is simply two of the same lines that already exist in other parts of your home. So, unless your kids are especially gifted at getting things into sockets they are likely to get 120 (one leg).

Besides that, the transformer being suggested by others has the same liability as it produces 240 volt as well.

The plus of the transformer is it can move with you to another home. The plus for dedicated 240V line is better sound (in my opinion) and probably cost less. Remember too, future buyers of your home can split that 240 back into twin dedicated 120 volt lines to run whatever they please.

It's not a bad thing to have.
As my electrician friend told me its amps not volts that kill.
Gregadd - I think your buddy would tell you that twice the volts gets you twice the amps, when other factors are equal.
He is right though when conditions are right it doesn't take high voltage to drive enough current to hurt or kill.

Glrtrgi - I really don't have issue with 240v lines, and as noted above you are going to have a 240v outlet somewhere unless you wire directly from tranny, just think it is good to be aware of the potential hazards.

Albertporter - "unless your kids are especially gifted at getting things into sockets they are likely to get 120 (one leg)." The lucky kid goes 120-ground, the unlucky goes +120 -120, just touching 120 is usually free unless you are in contact with a grounded surface. Not sure why one would be more likely than another.
The better sound opinion is interesting (why , in what way, how determined?) if you are in the mood to elaborate.

Happy listening
I can't speak for Albert of course, but I've experimented with all sorts of transformers in the course of my meandering audiophile career. To my mind and experience most of them interfere with dynamics in the musical signal, so also for me a direct dedicated line has been the preferred choice.
Happy listening,
"think your buddy would tell you that twice the volts gets you twice the amps, when other factors are equal."

Makes sense since my 120 line fuse is 15 amps and my 220 line fuse for ac is 30 amps.
Point is you can get a high voltage low amp line.
Today's' circuits are safe. They even have lines that detect a short and shut off. (Modern bathrooms and kitchens are required to have such a circuit by code. Just in case you drop the hair dryer into the tub.)A determined individual can still electrocute themselves.
Detlof - Thanks for the feedback, am trying to understand. I assume you are specifically refering to power transformers and not transformers in the audio signal path?
Yes of course. Sorry to have been unclear (:
Consumer grade step-up transformers are usually poor quality and not really transformers but autoformers and have virtually no AC filtering.

Industrial grade step-down transformers can, technically, be wired backwards but, although I've never tried, I'll bet that would be noisy.

So, in this case, I'll suspend my normal xformer promoting and go along with the 240V line. Not because a well selected transformer would degrade sound. 240V also provides balanced AC, or close enough, which some gear appreciates. However, an electrician might wisely and legally insist using 240V outlets or horizontal spades so that nothing 120V can be plugged in. Which means that your power cords would have to be modified. Might even insist on GFCI's.

BTW, twice the volts is half the amps.
Detlof have answered the same way I would have. I don't like transformers hanging on amps.

In my system I use one isolation transformer that drops (USA) 120 Volt to (Japan) 100 volt to supply the motor controller for my Technics MK3. Even though it's a simple job, I opted for a large transformer rated 10 times over, in hope it would not damage performance.

As Detlof said, transformers typically damage dynamics and I've had my share here for trial.
Me - "twice the volts gets you twice the amps". In context of electrocution hazard.
Ngjockey - "BTW,twice the volts is half the amps". In context of transformer characteristics.

Alberporter & Detlof - Thanks for the feedback. 'Damage dynamics' gives me a bit more to think about.

1. We all like specific types of disortion in our audio. My personal favorite is the high magnitude even order harmonic distortion that you get with vaccum tubes.
2. It seems reasonably well established that distortion in the upper frequency range can make music sound more dynamic. For example Vandersteen goes to the expense of installing back firing tweeters on their 5a's because some listeners/systems benefit from the timing and frequency distortion inherent to bouncing tweeters off of back walls & etc.
3. If a person is basically happy with their system & then they insert a device that tends to eliminate higher frequency distortion would this most likely be percieved as a loss of dynamics?
"My personal favorite is the high magnitude even order harmonic distortion that you get with vaccum (sic)tubes."

Not to get off topic but the more accurate statement is, if tubes have distortion it is more likely to be even order.
The better tube designs can sound quite neutral.
Gregadd - "tube designs can sound quite neutral." Agreed, but would they still sound neutral without signal distortion? I think that the electrical distortion which creates the illusion of natural acoustic distortion, or tends to fill in the signal loss inherent to recording & playback, is part of what we like about our systems.

"...Agreed, but would they still sound neutral without signal distortion?..."

"Without signal distortion." That is neutrality defined. Second order harmonics is a pleasant distortion. But distortion none the less.

Second order distortion is not inherent in tube designs.
Gregadd - I'm giving up at this point. Regards.
Thanks for all the responses. Unfortunately I do not have the ability to put in a dedicated 240 line. I also discovered that the transformer I was given by the manufacturer of the amp to "solve my problem" apparently is quite inexpensive...less than $50. The more I read the above responses the more I feel that I have been put in a rather untenable position by the mfg. - sending the amp back to the mfg. to "re-wire" the amp will cost hundreds of $. To clarify, it was never agreed to when I bought the amp that it would not work on 110 volt power without using a transformer. I guess this is why buying product over a long distance is so risky.

Finally, the mfg swears that the transformer makes no difference in the sound of the amplifier. I seem to hear some high end hash from the amp which may be a function of the cables, but the high frequencies are beginning to, more and more, grate on my ears.
Glrtrgi. After you've had awhile to listen with the transformer why not do a test. I assume you have a clothes dryer in your place? Run a cord from that outlet to the amp and see if that changes the sound for the better.

If not, you have the wrong amp regardless of power and should look to possibly change. If the dryer outlet (220 volt) solves the grate on your ears problem, the transformer is not suitable.

The dryer cord should not be expensive and if you need additional length you can use Romex to hook up. If you're not comfortable with such things get a pro to help with the experiment. Even if you have to pay a bit it's better than getting shocked and better than being angry over your sound and not knowing what's the right direction.