|The original reproducer is tarnished, so some cosmetic cleaning is needed. But more importantly, the real reason for the rebuild is that the rubber gasket materials have dried out, and no longer allow the diaphragm to vibrate freely in the housing. The mica diaphragm itself may also be "fatigued", so I generally replace that as well. And most often on the Exhibition, the back rubber flange, which attaches the reproducer to the tone arm, has dried out and can no longer provide the air-tight fit necessary for maximum reproduction|
|The first step is to gather together the proper tools and parts needed for the rebuild. For the Exhibition, we need two lengths of gasket rubber (these are hollow tubes of flexible rubber), a mica diaphragm of appropriate size, a replacement back rubber flange (if needed), a small bit of bees wax, a soldering iron (don't worry...no real soldering here...it's just to melt the wax!). You should also have a good set of jewelers screwdrivers in varying sizes. This is very important, as the functional and cosmetic integrity of the screws are maintained by using the proper size screndriver.|
NOTE: Since many of the parts are very small and nearly impossible to find if dropped, I recommend that you perform the entire process in a Frisbee, shoebox lid, or similar shallow, lipped container. That way, if you drop a tiny screw, it can't go far.The first step, of course, is to disassemble the reproducer. We first remove the two screws holding the black rubber back flange in place. Set these aside and remove the rubber flange.
Then remove the three screws holding the reproducer back in place. Often these will be rusted tight and will not easily break free (be careful not to damage the screw head! This is why it is so important to use the screwdriver of correct size).
Putting a little "3-in-1" or "Kroil" on the heads and letting them sit may help free them. I usually have alot of success putting the whole reproducer in the freezer for an hour or so, and then trying it.
Next, remove the very tiny screw that holds the diaphragm to the needle bar. This will usually be covered with a small bit of wax, so it usually helps to scrape the wax out of the screw head first. Be careful with this screw! It is very tiny and very easily lost!
Now remove the back. It is often held in place by the dried out rubber gaskets, so a little help may be necessary by gently prying it apart with a screwdriver.
|A small screwdriver wedged underneath it may help to loosen the first rubber gasket for removal.|
|A gentle push from the other side should pop the diaphragm free.|
|And finally, the second gasket is removed.|
|This is now a good time to remove the tarnish and polish the reproducer body.
NOTE: Be careful when cleaning a gold-plated body, as it is easy to remove the gold.See how just a little effort has made half this body shine!
|Now we insert the first piece of gasket material into the reproducer. The seam where the two ends meet should be at the bottom, so that the seam is hidden from view by the needle bar.|
|Lay the diaphragm in place, and make sure that the needle bar just barely touches it. When screwed into place, you don't want it pulling or pushing on the diahragm while at rest. If it needs adjusting, there are two small nuts on the needle bar springs that are used for this, but without the proper tiny wrench, you can often just gently press it into position. Screw the tiny screw back into place.|
|Before you insert the second gasket, see that the diaphragm is not touching the sides of the reproducer. You may need to gently press the needle bar a little to center it. Lay the second gasket in place, this time placing the seam, where the two ends meet, at the top (opposite of the first one).|
|Now you can reassemble the back of the reproducer and screw it back into place.|
|A light coating of Vaseline between the reproducer body and the new rubber flange will help insure a nice air-tight fit. When you screw the flange back on, note the location of the small pin near one of the screw holes. This is used for locking the reproducer in place on the tonearm, and should be in the "One O'clock" position when fastened back on the reproducer.|
|The final step is to place a small ball of wax against the diaphragm/needle bar screw, and melt this by heating the needle bar with the soldering iron.
This will help insure a good solid airtight fit around the screw, as well as prevent the vibrations from loosening it.
Not only does the finished reproducer look much better, but it will sound much better! And you shouldn't have to rebuild this one for another hundred years!