Mix of RCA Balanced Cables. Is it ok?

I have been advised against using RCA and Balanced cables both in the same system. I was told that unless you have balanced cables all round, you are wasting your money. How true is this?

Does anyone know if RCA to Balance converters actually work? I think there are 2 types, one is the little plug kind and the other is a chassis kind. Any advice would be greatly appreciated. Thanks.
No, I don't think so. I have a BAT VK50SE and a BAT VK60. I have balanced from my CD and analog sources, but RCA from SAT and DVD. They sound fine. The balanced does help, if the components are truly balanced. Stick with balanced where you can, but it's not life or death.
The above advice is good - if it is a long run cable then balanced will help with picking up noise along the way and sometimes it will add some gain to the situation which may benefit your components - otherwise it is just one of those extra deal/cost things.
I agree with Jfrech. I have my Aesthetix Io phono stage running balanced to my Aesthetix Callisto preamp. The Aesthetix pieces are true balanced and work well that way. My Wolcott amps are single ended design, so I choose to drive the 11 meter run as such, and it performs flawlessly. As mentioned by Jfrech, the pieces that are truly balanced may benefit from being run that way, adaptors may even hurt the performance.
Thanks pple, for your contributions so far. Is it wise then to convert from RCA to balanced?
An RCA to XLR adaptor will not convert the audio signal from single-ended to balanced. The adaptor simply allows you to mate different types of connectors. There are real sonic advantages to fully balanced equipment. For interconnects, a balanced cable will have better RFI/EM rejection and balanced amplifier circuits typically have lower distortion than comparable single-ended designs. If you have such equipment, then by all means used balanced interconnects.
All balanced is better, but sometimes compromise is unavoidable. My BAT preamp is all blanced inputs and outputs, but my phono preamp and amps are RCA. I used adapters for a while, but when I bought new cables I had them temrinated w/ XLR at one end and RCA's at the other. Not the same as balanced, of course, but at least it avoids an extra connection in the signal path.
In the past year I have gone to a all krell/thiel system. Krell recomends going balanced if you can but the equipment must be desinged balanced. There is a 6db increase in S/N. Initally I used higher end RCA's then I ordered cheap balanced interconnects to test the therory. The cheap 15.00 balanced totally blew away the Single ended 100.00 plus cables! I later purchased more apropriate Strait Wire Bal. but surprisingly no great improvement over the cheapies but they sure look cool! Ken Martin
From what I have heard or read and in my personal experience as well, there is NO fixed rule you can go by. There are guidelines, like balanced ic often being less prone to noise, however if they are indeed musically more satisfying in a given rig is question of listening for oneself. There are plenty suppliers around, where you can borrow cables and try them out for yourself in your on home in order to make up your own mind. I personally use a happy mix of both XLR's and RCA's with no detriment to my dayly enjoyment of the music.
At this point, I feel that I have come to recognise that as Jfrech has said, it is really neither life or death and using a mix of cables shouldn't have an effect on daily enjoyment of music as pointed out by Detlof. Thanks for all who have contributed. I really appreciate your inputs. Cheers and have a nice day. By the way, I'm gonna get my first balanced cables. :)