Tube Amplification Question

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For some weird reason i couldnt find, the other day it worked perfectly. Loud  good signal with a tiny(normal) hum in the backround.
But yesterday bad news again :(  Suddenly while i was recording smthng for fun, a soft "crackle" and then big output loss (you can barely hear a tiny signal after the crackle in the recording i attach below).
Sorry for asking again but it drives me crazy. Any thoughts? While tubes warm up there is  small "cranchy" noise from tubes but i dont think it's so bad.

It could be dirty/loose pins tube socket. Actually some pins of tube socket can be moved up and down but when tube is inserted all keep stable. Output jack socket also is ultra dirty but problem appears too from speakers (it has switch: headphone out-speakers) so i guess its not culprit. I passed signal from PC into the input of amp but the same low output. So the problem must be into the amp. When it was OK though(yesterday) and i was punching/moving etc the socket jack, the small hum was getting lower but also the signal too. When inserting jack also sometimes made little sparks and the classic scratchy sound. Also, when i move my body close to master volume pot i get buzz, when i touch even the plastic knob it gets max. and when i leave it its gone. I grounded pot's metal case but the same.
If that helps the situation seems to change every time i power it on. For example yesterday low volume, today morning extremelly weak, in the afternoon a little better but still low, after 3 hours almost no sound at all. And after a while a bit better again. But during every powering its stable. By weak signal i mean "like it begs for pre and amplification, really low.

I think either bad power tubes, or loose/dirty pin socjets or (i hope no) bad OT (or they are "pregnant or not" situation?) ... Or a dirty jack socket output but then i should at least get normal signal from speakers . And i don't...

IMPORTANT:
When turning off i have very strong pop clip sound, i don't know if it's normal.

But the worst of all (i have triple checked it) :  While i was measuring filter cap voltages i left the multimeter open and after switching the amp OFF the voltages decreased to Zero immediatelly !  My filter capacitors  cannot keep their charge voltage more than 1-2 seconds !! :(

Please, help, it drives me crazy  :(

Here is the sudden output loss: https://www.mediafire.com/file/7bhs3ebt1ev9b4n/Sudden_Loss.mp3/file
 
Voltage measurement of filter cap.
Notice when i turn OFF the organ , the instantaneously (nano-seconds) extrem increase in voltage (1880V. or smthng wtf??) and then immediatelly 0V.
Is this normal??? :( :(


https://www.mediafire.com/file/cc2qm0n1yobt8bi/VID_20190329_030332.mp4/file
 
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