In-Wall Wiring issues?

As a part of my studio build, I wired many different types of connections throughout the studio... pretty standard stuff. Everything has been tested, and works fine with regard to connectivity and phase. I have had no issues with any of the wiring, EXCEPT that is, with a guitar (instrument) lead. When connecting a guitar in the live room through the wall into an amp in the iso room, there is a significant loss of tone compared to plugging directly into the amp. The amp was set up with a bit of gain and some mild distortion. However when played via the in-wall wiring, the tone went to very clean without the distortion of the direct cable. The connections in this case are on opposite sides of a wall, so the wire length is very short. Basically, I have a 1/4" jack on one side of the wall, a short stretch of wire between the walls, and then a 1/4" jack on the other side of the wall. The solder joints are fine, and the cable is high-end Mogami instrument cable, so there should not be any issues there. To add to the puzzle, I have a PAIR of connections, and they both exhibit the same behavior. Is this normal? Have I done something wrong? Thanks!

How short is short? Did you use high capacitance wire in the wall? Does the same thing happen if use a longer guitar cord right to the amplifier? Andre

AVare wrote:

How short is short? Did you use high capacitance wire in the wall? Does the same thing happen if use a longer guitar cord right to the amplifier? Andre

I am guessing that these particular leads are 3 feet or so. Yes, I used Mogami shielded instrument cable. Direct connect with 20 foot cables sounds fine.

Are the connectors insulated from the plates? Andre

AVare wrote:

Are the connectors insulated from the plates? Andre

No, and that is exactly what I am thinking at this point. I am going to isolate them and see what comes up. Thanks for the advice.

Well, I had quite a frustrating night trying to troubleshoot this issue. Continuity testing tells me that things are wired properly, yet my cable tester and my ears told me otherwise! Isolating the jacks did not solve the problem... To make a long story short... I called Redco, the company that I buy all of my cable and connectors from, and talked to Chris (he is amazing), and we figured out the problem. The cable that I am using is a high-quality Mogami cable that is designed for stage use. The center wire is sealed in a relatively hard plastic enclosure that is *then* wrapped in a thin, black conductive sheath. Then there is obviously the woven ground wire around this. This thin black sheath needs to be stripped back from the center wire to prevent issues. This material is great for reducing cable noise on stage, but in my case, it was causing me unending problems!!! This material is apparently conductive enough to show up on the cable tester and will adversely effect the sound, BUT not conductive enough to show up using simple continuity testing of my multimeter! Weird! Anyway, I carefully peeled back this sheath material, and VOILA! Instant success!!! Now I need to go back and do the same to the other cables that have the same issues. Thanks for you help!