I have assembled a 5F1 from scratch and I'm at the stage of testing voltages and plugging in the tubes. I'm following Robrob's startup procedure https://robrobinette.com/Tube_Amp_Startup.htm I'm almost there! I got to testing the DC bias voltage on pin 5 of the power tube socket and I got a reading of 18.6v. Sometimes fluctuating to 15v and 22v. His instructions say I should get a voltage between -30v and -60v. My readings are way off in the positive. Does anyone know whats gone wrong? I don't want to plug in the power tube and have it blow up! Here are my testing notes... I'm using a light bulb limiter. With no tubes plugged in... Voltage at fuse 234VAC (I'm in Australia using Classictone power transformer wired for 240v) Rectifier tube heater wires 5.45VAC Preamp and power tube heaters 6.5VAC High voltage wire 333VAC x2 Installed rectifier tube... Filter caps all test at 388VDC Preamp tube pins 1&6 388VDC Output transformer 390VDC Installed preamp tube... Preamp tube pins 4&9/5&9 5VAC ***is this low? robrob says I should have between 5.9v and 7v Preamp pin 1 259VDC Preamp pin 3 1.75VDC Preamp pin 6 261VDC Preamp pin 8 1.83VDC Power tube pin 5 18.6VDC <------01000110 01010101 01000011 01001011 (me swearing in binary) HELP!!!!