Question about a vintage credenza

Not a moss-covered three-handled family credenza, mind you, but one of those self-contained hi-fi cabinets from days gone by.


Turns out I found one on the way home from work yesterday. It was standing beside the road with a "Works! Free!" sign on it. Since the price was right, I man-handled it into the car.

"Works" might be overstating it, though. The turn table turns, which is a plus, but there's an overwhelming hum whenever the stereo is on, and regardless of mode.

It's an RCA stereo dating (if I had to guess) from the late 60s to early 70s. There's a model number on the label, but it's faded and hard to read. I'll try and decipher it tomorrow.


Any idea what might cause the humming? A friend suggested that it might need to be grounded, speculating that it might have been wired previously with a now-absent preamp.

Sure, I can take it to a stereo repair place--if they exist anymore--but where's the fun in that?

We don't have a lot of vinyl, but until yesterday we had no turntable at all and were reluctant to put much money toward it.


Just happened to be in the right place at the right time!

Transistor, actually.

Does that mess up my guess as to its age?

Dates back to the days of big hulking transistors, which have a tendency to short out and fail. Touch them to see if they're hot. If you can't stand that much heat, you have your finger on the problem.

And those fuckers usually whistle when they are going bad and put off a rather pungent scent - sort of a cross between ammonia and dark-room chemicals. Not pleasant. If it was a transistor, I doubt there would be any sound at all, at least nothing you would want to hear.

Just setting the record straight.

As for the stereo, I've probably got the same damn one (or similar) and the turntable - came out of a unit with a TV built in and I used it as a receiver for years (made a silly but useful casing out of file folders). The hum is probably a bad tube. It is in a box right now, but I don't recall it having that many tubes. If you can identify the tube numbers I'm sure you can locate them on the net - just get all new ones. You'll save time and shipping costs.

As for the pre-amp, that was probably for the the turntable. They had some kind of ceramic cartridge that required a pre-amp to get much of anything out of it.

Sure, it could be a grounding issue, but I doubt it unless it is solid state. The most likely culprit there would be the turntable. If you remove power from the turntable and the humming stops, there's your problem. In an integrated unit that might not be so simple - could be soldered in.

Another possibility is, believe it or not, simple dust. The tuner probably has two sets of 3/4 round plates (a dozen or so each) that move between each other - it's just a big variable capacitor. If it is covered in dust and/or hair, it can cause conductance where you REALLY don't want it. You said "all modes", so that probably isn't the issue but not knowing the schematic makes it hard to tell. Either way, it can't hurt to get in there with a vacuum and clean the fucker up.

On Edit: Just saw the post above stating that it is solid state - so much for the tube theory.

But I anticipated copycats and/or in-thread jokes about it, so I thought that I'd take the gradunza by the horns.

this is a question about electronics, not furniture:P

...saying 'Beautiful Chest'. It led to a lady who showed me her best. She was taken by surprise when I quickly closed my eyes. She rang the bell and quick as hell, Bob the Knob came out on his job to see what the trouble was. 'Louise, is the gentleman hard to please?' - 'You're telling me!' Perhaps sir, if it's not too late, I can interest you in our old fashioned Scaffordshire plate?' 'Oh, no, not me, I'm a man of repute.' But the devil caught hold of my soul and a voice called out 'SHOOT!'"

"To save my steeple I visited people and for this I had gone when I met Little John. He told me of his strange foundation, conceived on site at the Woodstock nation. He had to hide his reputation. Twen poor twas salvation from door to door. But now with a pin-up GURU every week, it was Love and Peace Incorporated for all who seek! He hired me as a karma-mechanic with overall charms. Whose hands were now fit to receive alms."



That's just from memory, pardon any mistakes.

The model number is VLT34F, and to my pleasant surprise the manual is available for download https://www.samswebsite.com/en/photofact/search/index/model/VLT34F">HERE. Would this help me? Should I download it so that it's available if I take the stereo to be repaired?

I opened the back of the console and was able to unplug the "data line" from the turntable to the tuner, but the hum persisted. Does this reveal anything about the problem?