Step-up/down transformers degrade performance?

I live in London & want to buy American gear. Problem is current here is 240V. I've been advised to buy step-up transformers to attach to the units.
Has anyone any experience with these & how they affect performance of components (esp. CD players).
Would be grateful for any advise.
I would think it more sonically prudent and cheaper to convert or purchase gear that can be converted fairly easily to 240v.

Often times you can contact the manufacturer who can provide relatively simple instructions for you or an electronics guru to splice a couple of internal wires and then rewire them for 240v.

If your transformer is of good quality there is no degrade of performance. If possible try to install the transformer within the unit's housing - that spares you any special powercords.
Good luck!
I find, that the situation is not as simple as Aida suggests. Some transformers work, some do not. If you have a very transparent system, transormers can colour the overall voicing of a system and influence dynamics in a negative way.
It also depends where you want to use the transformer.They often restrict dynamics when used on the poweramp side. For high powered amps, EquiTechs ( can be a solution, which has the added advantage of balancing your powerline, but it is quite expensive. For frontend equipment, a PS Audio 300 or 600 could be considered (, which will input 240VAC and output clean 120 VAC power. Both these products have proven to be reliable and not detrimental in my system, which generally shows up every little change or tweak in the setup. Contrary obviously to Aida's experience, transformers have been a mixed bag for me.
I came from America, and now live in London. I have all 110V equipment,HDTV-DVD- Stereo-AVR , they all work .

High power amps should be converted.

I am using line conditioner/transformers for other high end components. E-mail me and I may be able to help you.
Thanx all for your responses. I'm keen on buying hi-end Classe equipt (esp Classe CDP1) from USA/Canada from Audiogon but haven't found a London hifi dealer who will do the conversion - it's apparently quite difficult.
Will look into the suggestions made & will report back in due course.
speak to customerservice at classe
they told me that their gear is 220vac compatible.
they are very helpful
In these days of the global economy most electronic equipments have power transformers with windings for 120 and 240 volts (sometimes more). Some equipment already has both windings connected, with a selector switch to be set according to where you live. If there is no switch, it's easy to disconnect the 120V winding wire and connect the 240V wire. The power cord wall plug will also need replacement to fit the 240V socket.
As to sound degradation due to transformers...I hate to tell you how many transformers your power has already been through before it gets to your house. Transformers are not evil! (except in the audio signal path). A 240V to 120V step down transformer adequate for high power amplifiers will be big, heavy, ugly, heat-producing, and not cheap. That's why it would be best to use any 240V capability that the equipment already has built in.
By the way, we have 240V here in the good old USA...that's what your stove, clothes dryer, well pump, air conditioner, etc runs on. Instead of buying power line conditioners, perhaps we should all be wiring up our audio equipment at 240V.