Symptom: Distorted audio
Make sure the Power switch in set to ON rather than STBY
Try changing to a different program source. If the distortion only exists on one source, check the component that produces that signal. If an FM signal is distorted, try listening to the same station on another radio.
If the distortion exists on more than one source, check the bias level of all four output tubes. If one or more tubeÕs plate current is out of the normal range (45 mA ±4 mA), use the Bias Adjust controls to set the correct bias.
Check the 12AT7 tubes. Your Red Rose Music dealer can test the tubes for you. Replace them if necessary.
If the amplifier is in Triode mode, reduce the volume and see if the distortion is only present during loud passages. You may be overdriving the amplifier. Switch to Ultralinear mode and try again.
