Hi, A couple of months ago I built the elekit tu8600s. The amp worked well for a while but then suddenly one of my 300B’s stopped working. After a while it worked again but then after some weeks it didn’t work again for a little while, this repeated a couple of times untill ik broke down for good. I then looked inside the amp and checked the voltages and found that tp 13,14, 23 an 24 are double what they should be. I checked if all the parts where in the wrong place and redid some soldering, but I can’t seem to find my mistake. Is there anyone who had a similar problem and can help me?
I did swap the two tubes that I had which showed that one of the tubes was broken and not the amp. But because it was only a few months old I suspected that a mistake inside the amp caused the tube to break and that’s when I found the very high voltages, which strengthened my suspicions that the tube broke because of a mistake I made.
At tp13 I have 597V instead of 330V
At tp14 I have 600V instead of 330V
At tp23 I have 701V instead of 365V
At tp24 I have 690V instead of 365V
At tp14 I have 600V instead of 330V
At tp23 I have 701V instead of 365V
At tp24 I have 690V instead of 365V
if you look at the schematic , PT 34-38 are AC..NOT DC..
PT 35 and 36 should be 6.5V AC .. please check
PT 35 and 36 should be 6.5V AC .. please check
I now have 6.9 at pt35 an 6.7 at pt36. I however also measured them as ac voltage before and got a different result (the ones I wrote down on the paper)
I’ve measured everything again and and I got the same as before (pt 35 and 36 where high again), but then I checked again and they were low again. I then checked tp 24 and it was 383 and not 700 anymore
Some of the voltages that where very high are now closer to what they should be, I’ll measure again and write down what I get
The test points are extremely high. 700 is impossible high..
I do not know whether the problem is your amp or your multimeter.
I do not know whether the problem is your amp or your multimeter.
Could be the multimeter maybe. I’ll get a new one tomorrow (stores are closed today in Belgium) and measure again.
These are the last results I got, some are different again:
These are the last results I got, some are different again: