Extension cable on Stax earspeakers

Hi, is anyone using Stax earspeakers with the SRE-725 (or 750) extension cable? Does the use of the extension cable change or even degrade the sound in any way? I have the SR-404 earspeakers myself, but I guess any effect would probably be noticeable with any of the others as well.
Thanks in advance
I use A 12'extention (model???) with Stax sr80 pro phones and do not notice any ill effects, but frankly I have never done a careful a/b comparison.
Thanks Mapman, I bit the bullet and bought a 2.5m extension used. And I'll try to do exactly what you did: just listen to music and NOT A/B, trying to convince myself that the tympany sounds 1 notch less silver-hued on a scale of 1,000 :^o