Audiophilepure

Read Here

“Turning on the IS250 was a bit tricky, and is not well described in the manual; here’s what I found: After everything is connected and the IS250’s power cord is plugged into the IEC socket on the rear panel, first turn on the power switch adjacent to that socket. This places the IS250 in standby mode; the LED over the Power/Mute button on the front panel should glow red. Turn the volume control all the way down. Now, push and hold down the Power/Mute button for about a second. That will take the amp out of standby, warm up the tubes, and get it ready to play. ”