Cable length and Patchbays

[gaz7224]

Hi all,

What are the maximum lengths of Mdi Cables and unbalanced leads.  Is there a way to convert unbalaced to balanced if the output is unbalaced (Jack) but the input is balanced (XLR)?  for example, my live room will be about 40 feet away from my control room (if wires are run neatly), and I'd like a decent keyboard in the live room (I haven't seen one with balanced outputs), plus I'm having an electronic kit to midi trigger addictive drums, so I'm concerned about cable length. 

Also do patchbays degrade a signal?  For example, I'm thinking of a xlr wall panel in the live room, connected to a XLR Panel in a rack in the control room.  Then having another xlr panel connected to my mic pre's.  This seems the most flexible as I can patch any source from the live room to any input in the mic pre. But I'm wondering if this will degrade the signal by going in and out a couple of patchbays?  Would it be better to just hardwire the live room wall plate directly to the pre-amp?   

Thanks.

[RazorLand Studio]

I am currently runing 50 ft of high quality midi cable from my drum kit to the usb interface  and into the computer with no problems whatsoever.  Have yet to run into and problems with cable lengths as long as they are balanced cable runs ie: XLR or TRS. As far as your keyboard dilema, run the unbalanced signal from the keys into a balanced direct box to convert the signal to a balanced run, then use XLR from there to your input source, that will fix and hum or buzz problems and will greatly reduce and hiss you might experience with unbalanced lines. 
If you do good clean solder connections on your wall panels and all your balanced cables there will be no problems with using short balanced patch cables from the panel to the inputs on your pre amps.

[gaz7224]

Thanks, you answered my question.

I didn't realise DI boxes could be used to convert unbalanced signals to balanced signals.  Sounds exactly what I'll need.

Gaz