18-07-2020, 06:11 PM
(This post was last modified: 18-07-2020, 06:15 PM by Murphyv310.)
You need to have all valves fitted and scope the output of the EZ81 cathode which is connected to the reservoir capacitor. Measure the DC volts there with a meter and also see what peak to peak voltage ripple there is on the scope. Then do the same on the smoothing capacitor C4, there should be only a very small ripple just a few milli volts.
I'll ask again is the new transformer wired the same way as the original?
Unless you have wired the heaters without the centre tap or earthed one end of the heaters it's not there you should be looking at. You should check the HT side first then look for hum loops, badly routed wiring, heater/cathode leaks in the ECC82's etc
I'll ask again is the new transformer wired the same way as the original?
Unless you have wired the heaters without the centre tap or earthed one end of the heaters it's not there you should be looking at. You should check the HT side first then look for hum loops, badly routed wiring, heater/cathode leaks in the ECC82's etc
