which XLR cables?

FWIW.... amps are parasound HCA 1500a
pre/pro is the integra 9.8

is it worth looking to XLR cables or should I stick with what I have? I do plan on getting a bryston amp (or something similar) in a year or so for the mains

Recently used Discovery Cable interconnects in balanced configuration. Priced very right indeed plus offer all the performance of the big time brands. Were highly reviewed in TAS and now I know why, just cannot be beat in the price/performance catgeory.

Here's some opinions I hold. Whether balanced will be better than single ended is totally dependent on the equipment being connected, as some have indicated. I have only come across around a dozen brands where balanced will work better, and that assumes you have one of those brands at both ends of the cable. As a very wild generalisation single ended will most times be better. When balanced is better, it is true that there is less difference between the sound of cables than for single ended cables, but there is still a difference.

Viggen900 -- My system has always had just single-ended interconnects, so I can't offer an opinion on your original question. But what might make sense is to experiment with inexpensive but well made xlr cables, such as those used with pro audio gear, and do some comparative listening with respect to single-ended connection before deciding whether or not to invest in more expensive audiophile-oriented xlr cables.

B&H Photo Video has a nice selection of pro-oriented xlr cables, that are generally well constructed (in my experience using some of them with pro audio gear) but very inexpensive:

http://www.bhphotovideo.com/c/shop/4174/Audio_Single_Cables_XLR_to_XLR_Cables.html

Also, on the question of single-ended vs. balanced interfaces, I'd like to add that one circumstance that particularly calls for the use of balanced mode would be if the ac power inputs to the two components are to any degree isolated from one another. Such as by being plugged into separate dedicated ac lines, which is commonly done to prevent cross coupling of digital noise into analog components, or being plugged into isolated outlets on a power conditioner, or because one component is plugged into a power conditioner or surge suppressor and the other (such as a power amp) is not.

While isolating components like that has upsides that are well recognized, it also has the downside of potentially introducing ground offsets between components, which can cause extraneous currents at noise or hum frequencies to flow in interconnect shields. That current would be directly seen as noise or hum by a destination component that is single-ended, but would generally be completely ignored in a balanced interface.

Elizabeth -- Good luck with the nice SP-15 purchase. I don't think you'll find any cheap op amps in there! :)

Regards,
-- Al