Miscellaneous Rumbles

Premier 71 photos

26

Chassis bolt, have no idea how they held the nut inside.

27

I'm beginning to think the chassis was bolted onto bottom board before case was finished, or this strip of wood was installed after chassis, it's too tall to pull out. Gonna chop of 3/4 " of wood strip. Cord barrier bolted onto bottom, have no way of getting to nut.

29

The offending inassable nut

30

Surprise indeed, output xmr wasent bolted on. Just hanging in the bottom by its wires. Probably vibrated out many years ago. 1.

31

Wood detail on front edge of cabinet

32

The following is way too many pics.

33

1

34

2

35

3

36

4

37

5

38

This light bulb has been working for sixty years. The amp only had its tubes replaced in 92'

39

Now I gotta try to draw out the circuit. If anyone wants any other angle pic, now it the time to ask. .

40

Less fuzzy pic

41

Cap

42

And now the fun part.....

43

Been a long time....first tube. First draft. Will be neater when I re draw it.

44

Noticed something interesting. The wires near the solder are spidering off the terminals. Long term acid damage. Amp is 60 years old. Close as could get the shot. Zoom on red wire on splicing bar.

45

Could be Tin Whiskers. Metal whiskering is a phenomenon which occurs in electrical devices. Tin whiskers were noticed and documented in the vacuum tube era of electronics early in the 20th century, in equipment which used pure, or almost pure, tin solder in their production. It was noticed that small metal hairs or tendrils grew between metal solder pads causing short circuits.

46

Thank mj. Seems to be the case as wires are solid. I think im done for the day. Been at it hard. Now to turn this point to point into a trye schematic. See any obvious mistakes anyone? Its been years since ive done this stuff.

47

Pinout ect. Getting ready for next phase. It does look simular to the 77 huh?

48

Oops

49

I hope i didnt miss any wires or components. Gotta do the controls and the redraw.

50

That looks pretty good Mun. Should be able to make a schematic from that.


Register Sign in to join the conversation