Voltage Adaptation - Help an Unknowledgeable Buyer

A european seller has a CD player for sale which I want.
It has a voltage of 230V. Seller offers to send a transformer
rated 110-230V. Will this work? Can voltage be adapted / modified to play safely here in US without degrading sound quality?
You should check with the manufacturer, as it not not just a voltage difference, there is also a frequency difference. Europe spec is 50Hz, US runs 60 Hz.
I don't have any technical knowledge about this but I've been using a European model, 230V, Cambridge Audio CD4 player with a Powerbright 100W transformer that I bought new for less than $20 online. It works and sounds great.
I think you should be fine, the frequency should not be an issue for this sort of a component. The voltage conversion would surely affect a power amplifier's sound quality... but I don't think it would be a problem for a CD player.
One thing worth checking with the manufacturer, would be whether the unit could be converted (by a switch inside or in the worst case a little soldering) to 120 Volts. Something else you might want to consider is that in the future it will be more difficult to sell that CDP in the US than a local 120V unit.

What CDP are you thinking of?
Thanks for everyone's help; it was a Lector CDP but
has since sold & I realize I'm better off looking for one
built for U.S. operation.