TU-666 how much work should I do?

c.coyle

Fighting the Dunning-Kruger effect.
My TU-666 tuner came today. It was an Ebay purchase. I initially thought I had overpaid, but the condition is even better than advertised. Clean inside and out. A few dings on the faceplate, and just a scuff or two on the wooden cabinet. Everything works except the stereo light, and I'm hoping it's just a bulb. Selector switch is a little scratchy.

It sounds good into my AU-555a, AM and FM stations are about where they should be on the dial, sensitivity seems better than my Kenwood tuner, and the green dial is just gorgeous. No way I'm going to put in LEDs.

Solder joints and boards look fine, no heat damage that I can see, none of the original electrolytics is swollen or leaking.

I'm tempted to just re-do the power supply, replace the four 2SC458s, and leave it at that. Leave all the other caps alone. I haven't found any threads talking about any other known failure-prone components.

But, I like to tinker.

What would you do?
 
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I always replace all the electrolytics. New capacitors are better than originals. Even new transistors are better than old. All new components generally are smaller and quieter than the old. For me the line is hard to draw. Most times though, I replace capacitors diodes and just the known bad transistors. Leave the rest unless their ate up by the glue.
 
I would definitely do what you suggested in your first post, and any power line filtering electrolytic capacitors anywhere in the tuner. How much more is up to you, bearing in mind that for best possible results an alignment check, or full alignment may be beneficial. (in which case you could change all the electrolytic capacitors)
 
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Is the bulb dead or is it possibly not receiving in stereo?

If the bulb is good then an alignment will be needed....therefore more re-capping.

The dial lamps are easy to replace, I'd do all of them now.
 
Stereo bulb's good, but I'm not hearing stereo. The bulb grommet was glued in (someone was too lazy to get the right sized grommet), and VR-401's position was marked with a sharpie. Looks like someone was here before. The stereo bulb has radial leads and is marked "(S)91". I can't tell if it's original.

I'm not inclined to mess with the multiplex board, other than replacing caps.

The plan is to do a full recap, get rid of the 2SC458s, do a PS rebuild, then have the alignment checked.
 
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