UK to US step up/down voltage converter


Does anyone know of a step up/down device into which I can connect a UK line cord (male)  through to an aftermarket female line cord? Nothing I have been able to find has the requisite fittings. Am I missing something really obvious? This doesn't seem to me at all exotic. 
ott
I'm using a UK DAC (Cambridge Audio Azur 851D) with a hard-wired line cord; that's fit with a Schuko plug. The DAC will be powered from an Audioquest NRG 10 cord plugged into a Furman line conditioner. So the step device needs to accept the male Schuko for output at 230V, and the end of NRG 10 without prongs for input, or 110V source. 
Thanks for your response. 
This is a good site for step up/down transformers:

http://www.eastwestusastore.com/product-voltage+transformers-543-577.html

See my previous post on this subject. You need to make sure the DAC is not restricted to 50Hz only, don't think it is.
My local audio shop have consented to convert the DAC to 110 for a reasonable price. Happy ending! 
Thank you very much for your help.