041206 1008 - indago posted:

I have two sets of Koss Pro 4AA Earphones that I purchased around 1965. I
use them for television programs, especially the good movies. I like these
particular sets because the bass is not so prominent and the buzz that is
inherent in the tv does not seem so prominent in these phones as some of the
newer earphones.

I am having problems with the sound reproducers. While I am watching a
program in stereo, I can detect the left channel beginning to fade, the
moreso, until it is completely off, while the right channel continues. I
have a long stereo cable from the tv to the headphones, about 10 feet. I
have checked the cables and these are not the problem. I can apply the
leads of a 1.5 volt batter in a battery holder, scratching the leads onto
the stereo connector, and the right side is quite clear with the pulses, but
the left side is dead at first, and then recovers and responds to the
pulses.

I would like to know if anyone has had a similar problem with these
earphones. I don't want to send them back to Koss for replacement of the
reproducer because they might put in one that has a greater bass response
and I don't want that for these particular earphones.


Well, I found the problem. A couple of years ago I put a new 10' cable on
the Koss headset and took off the old "liquid filled" pads and put on the
new foam filled pads. I soldered the new wires together and taped them. I
recently took the covers off and examined into the wiring and found that the
tape that I used had unraveled and the joints became exposed and were
possibly shorting against the metal of the reproducer. I have since used a
different type of tape -- the heat from my head during use may have
contributed to the unravelling -- and retaped the splices. I have put in a
new felt separator that separates the splices from the reproducer, and also
acts as a sound baffler. The set has been working flawlessly now for a
couple of days and I am much pleased with these old headphones performance
in this particular application. The new foam filled ear cushions are much
more comfortable than the old worn out "liquid filled" ones.