[Crist Rigott]

Originally Posted by Electronic M

They probably selected "controlled warm up" tubes (octals often had a 'GTA' or 'GTB' post fix to identify that IIRC) for the design...Controlled warm up tubes would warm up in sync IIRC by sensing heater current so no tube would be momentarily taking a bigger portion of the voltage than designed.

A thermistor or dropping resistor would not hurt, but is not essential either IMO.

Makes sense. Thanks Tom.