Based on my calculation, Say 100 ohms and current is 280ma ( Max 70ma per KT88). The voltage drops will be 100 x .28 = 28V. Given W=VI So the watt require is only 7.84W, so a 10Watt should be good enough. Can you measure the voltage before the resistor and after the resistor to see what is the problem. You mention that there is some "Ng Ng" with the resistor, Should it be "Wu Wu" sound? If that was the case, it means the filtering without the resistor is not eoungh. There is another way you shoud try is to increase the filtering of the first stage. At the moment , we use 100u+100ohms+100h fitlering, you should try to use 200U+100ohms+100u, In this case, you short two + on capcaitor and connect the 100 ohms between two jenesen and move the 1K to the second jenesen caps. Three is no need to put on the 100 ohms for the second caps.
I think you better use 50 ohms , the filtering effect is ok but the voltage will not be that great.
The quality of the power transformer is not so good as it indicates that its internal resistance is very great. |