::This Emerson R167 just makes a spit, spit, spit sound when volume is turned up. If I touch a long wire to the arm of the volume control there is no hum out of the speaker just whistling sounds. All tubes check good and I have changed the two 8 mikes in the power supply. There is good B+ to plates and screens and there is plenty of signal on the plate of the 6D6 but from there on I'm lost.