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12.1.2 AC Voltage Checks
As long as the fuse has not blown then you are in business. With no tubes – let's check some AC
voltages first.
On the ECF80/EL34 PCB check the 6V3 6A filaments. Look for 6V3 6A on the ECF80/EL34
PCB near the Output Transformers – use your voltmeter leads and with one lead on each
pad check for 6.3 - 6.7V AC. Also on the ECF80/EL34 PCB check the 6V3 3A filaments on the
side near the Power Supply PCB.
Check the Blue & Yellow wires coming into the Power Supply PCB and you should see
approximately 300V AC here.
12.1.3 DC Voltage Checks
Now some DC voltage checks:
On the Power Supply PCB: you should have 375V DC between PS B+ and GND. Also measure
the B+ and GND on the ECF80/EL34 PCB – it should be the same voltage as they are directly
connected.
You can also check the A1 A2 (on both channels) on the ECF80/EL34 PCB with respect to
ground: you should see 366V – this is the Output Transformer.
