• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Motorola Console Salvage

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I've posted about the speakers in another thread: http://www.diyaudio.com/forums/showthread.php?s=&postid=1745443#post1745443

But, I've got some questions about the tube amp in an old Motorola console stereo. The tuner/phono stage is loaded with 12AX7. The power seems to come from a pair of EL84 per channel. Will have to re-check the stage before that. But:

1) What are the little white nodules on the outside of some of the tubes?
2) There seems to be a large amount of wax coming out of the chassis hole from the transformer...is the transformer blown?
3) Many of the signal chain caps are Motorola and have wax on the ends. Nothing looks to dry. Worth trying to re-use?

I will try to post picks of the wax buildup that seems to be from the transformer.

The model is a SK18-M. Anyone know anything about these? Thanks!
 
The wax leakage was sort of normal.It kinda tends to 'creep' out over the years.
If it looks like the wax has all been melted,and poured out of the transformer,that might be a sign of an overheated transformer. To be sure,check it for continuity with your DMM. :)

The old waxy caps are probably not worth re-using.Those older types of caps tend to be electrically leaky,some new 'Orange Drops' will only run a couple bucks so it's worth replacing them.

The white nodules on the tubes-I'm not entirely sure what you mean?

Sounds like it might make a nice little amp project. Good luck,let us know how it goes! :)
 
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