Not sure that i remember this correctly or not but are the 866's noiser than the 3B28's? No not the snap crackle pop they make when arcing over but warm up noise or just setting there waiting for the HV switch to be thrown. Kinda like sizzling meat, grease, or whatever makes. Seems i remember hearing that frying noise from my Valiant back about 30 years ago but maybe i was hearing things. Larry W0OGH