I have owned my Firestudio 26/26 for almost 12 years and never had a problem until a week ago. Mostly used on windows xp, but also used it at times with mac os elcaptian with universal control, which worked well for playback on monitor system when I use "capo" software on Mac. Last week all of the sudden the audio cuts in and out at different levels with no control on volume knob. I have tried new firewire cable on both systems and using the different firewire ports to no avail. I get the blue light showing sync on both systems. Sometimes when first started the audio will play at volume the firestudio is set, but cannot control volume from that point. Then after 5 to 10 minutes, the audio begins to cut in and out at different levels and then stops completely. I know this is probably the end of my firestudio 26/26, but thought I might ask to see if anyone has had this issue.