10 meters of interconect cable is too long.

The degradation in sonics is far greater than anything anyone has mentioned so far. Its nothing like what you think. The degradation that really matters is nothing to do with the length per se. It has to do with the fact that whatever you can afford to spend on the interconnect will buy you immensely more performance at 1m compared to 10.

Go ahead and do it if its so important. It better be.

Just noticed your $4500 budget. That kind of money will buy you 1m Synergistic Research Atmosphere Level 3 Euphoria with a ground block. This one interconnect will elevate your system above Kimber to a level you simply would have thought impossible. Instead you will spend that same money to achieve what can only be described as mediocre at best. Talk about degradation! 

Go ahead and do it if its so important. It better be. It really, really better be.

... next project will upgrade preamp with xlr connections.

FYI, simply adding XLR connectors to the preamp will not help, because you would still be sending single-ended signals into the cables. Unless, that is, major modifications were made to the preamp to allow it to generate true balanced signal pairs for each channel. That would likely involve addition of a tube, physically large output coupling capacitors, and other circuit elements, assuming there is room to fit all of those things.

Simply adding XLR connectors, while providing them with unbalanced signals, might result in minor sonic differences compared to running long RCA cables due to differences in the cables that are used. But those differences could just as easily be for the worse as for the better, compared to running long RCA cables.

The transformer approach I suggested is far more likely to be a good solution.

Good luck. Regards,
-- Al

A 30 foot speaker cable is much better than a 30 foot interconnect...........

A 30 foot speaker cable is much better than a 30 foot interconnect...........

It depends on many things. And over the years there have been a number of threads here in which the question of long speaker cables/short interconnects vs. short speaker cables/long interconnects has been discussed, with my perception being that a clear majority favors short speaker cables/long interconnects in most circumstances. In fact one of the advantages of monoblock amplifiers is often considered to be that they make it possible to have very short speaker cables.

Some of those dependencies: Preamp output impedance (the higher this is the more important it becomes to keep interconnects short, everything else being equal); speaker impedance (the lower this is the more important it becomes to keep speaker cables short, everything else being equal); balanced vs. unbalanced interconnects (balanced interconnects tend to handle long runs better); preamp compliance with balanced standard AES48 (which minimizes the importance of interconnect length); the internal grounding configurations of the preamp and amp (which affects susceptibility to ground loop issues, which is also affected by the resistance of the shield or other return conductor in interconnect cables, and resistance is proportional to length for a given cable type); and of course the characteristics of the specific make and model of the cables.

Regards,
-- Al
 

I think before I spent all that money for something I did not know for sure would work I would order something like this, from Monoprice or online.  You can buy two 35 foot RCA's for a total of about $30 plus shipping.  I don't know whether these being coaxial are ok for your application but the idea is try some cheaper cable first to see if it works at all.  Be careful if you go this route, some cables come as a pair of RCAs that are both in one sleeve. 
https://www.monoprice.com/product?p_id=2683