See https://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F011%5F002%5F016%5F000&product%5Fid=273%2D1380
Though this is a 1000 ohm to 8 ohm transformer and not 500 as CMDLGUY says is best, it has worked well for me in the past and at 3 bucks it is worth a shot. just wire it inline with cable your now using.

Kerry

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