Connecting Cable Box to Preamp

I'm setting up a Krell KSA-250 amp with a KAV-250p preamp that has balanced inputs. My source is classical music from my cabel box. The box has optical and HDMI imbedded outputs.

What do I need between my cable box and my preamp?
No expert, but I think the satellite signals are worse. The cable music is fine for background music. Do you have RCA outputs? If so, spend $15 and get the Monoprice RCA to XLR cables and give it a listen. A little more detail on your box and provider would help.
Do the satellite companies have better signals? What about a sate;lite radion receiver?
The quality of the signal over a cable box is usually pretty low, like 96 or 192 kbps. Assuming the cable box has RCA outs, I doubt that getting a separate DAC will provide much better sound than the DAC in the cable box. If the box has RCA outs, I would start with a set of RCA to balanced cables, like the ones available like the Monoprice for $5 a piece.

If the box does not have RCA outs, I would go with a very cheap DAC, given the low quality of the source. It does not have to have balanced out, since you can go RCA to balanced with cables or adapters.

I do not know what quality your cable provider delivers, but I doubt that this is ever going to be a high quality source.
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My box has an analog rca left & right out . It's a Cisco box from Bright House cable .
If yours does not , I would go optical out to a DAC . I think that HDMI would be overkill for 2 channel audio .

Happy Tunes
Are you sure that your cable box doesn't have analog (rca) outputs as well? If not, probably the best way to go would be to get a DAC that has an optical input.