Its great except the whistling/whining noise that starts up once its been on about 5 few minutes. At first I just hear a fan start up that kinda makes a ticking noise but after awhile it turns into a high-pitched humming/whinning sound thats even audibile when playing. Is this normal? Anyone else have a SVT-6 that does this? <!--[endif]--> The SVT-6 I bought was the only one Guitar Center had and in the Ampeg display for about a month so they told me I could trade for a boxed new one when it came in sometime before Jan 25 but my band is going on tour Jan 5 so I;m trying to figure out if I need to nag Guitar Center to get me a new one ASAP.