[R-390] The adventure begins (and a capacitor question).

[blw]

> So my R-390a has arrived.  I know there are things that one should do before
> turning it on.  I checked the fuses and replaced a bad one.  But then I cast
> all caution to the wind and turned it on.  I'm not sure if it's completely
> functional.  The line audio stuff doesn't seem to do anything, but it plays!
> Sounds great through a Klipsch Heresy.  A vintage speaker that's too ugly
> for my living room.  So the overpriced shipping may have worked out.
> 
> It's a little bit moody though.  Maybe a lazy capacitor or something like
> that.  So I'm thinking the first thing to do is start replacing capacitors.
> I'm guessing if it's electrolytic, tantalum, or paper, it wants to be
> replaced.  But my question is, what's the best capacitor to replace the
> paper capacitors with?  Polyester, polypropylene, ceramic or something else?
> I get the idea that the *orange drop* is popular, but has anybody ever
> thought of using ceramics to replace some of the paper ones?  Maybe they are
> even more reliable than the orange drops.  You can get 0.01 uf in a 1000V
> version, and you can even get 0.1uf in a 200V version.  So it may be
> possible to replace all of the papers with ceramics.  But I don't know if
> it's a good idea.  What do you guys think?
> 
> John

John,

Maybe you can do some other things first, and get better performance right
away.

The first thing would be to check all of the tubes. I cleaned all of the
pins on my tubes and put a tiny bit of DeOxit on each pin. I also cleaned
every connector and finished with DeOxit again. I did the crystals last.
Mine sounded like a different radio when I finished up.

All of this is easier than tearing into it first thing.

You get better audio from the diode load point instead of line audio. I
think it's #15 for positive audio out. You can get ground from #16.


Barry