What makes a good reproducer work well?

[OrthoFan]

There are some excellent tips here!

As to what makes a good reproducer work well, I'd have to default to something the late Bob Waltrip passed on to me about 30 years ago -- the needle bar should be free to move, with minimum tension, only in the direction required to track the needle's groove, and as much of the diaphragm's surface as possible should "plunge" with the movement of the needle bar.

I've listened to a number of Orthophonic sound boxes, and the best sounding ones, to my ears, had extremely flexible diaphragms that relied on the corrugated ring to pivot the diaphragm evenly. (The diaphragm, itself, would "flex" when tightening a needle.) A few sound boxes that sounded rather shrill on upper register notes, had less flexible diaphragms. There used to be an animated gif image of an Orthophonic sound box*** that showed the correct piston action of the diaphragm, but I haven't been able to locate it.

When Bob rebuilt my Exhibition sound box, he installed a conventional front gasket, and used a very thin bead of silicone calk for the (hidden) back gasket. As with the Orthophonic sound box, when I gently move the needle back and forth, the entire surface of the diaphragm moves in and out. This sound box will play most any type of record, and does a very good job with electrically recorded discs. It works as well today as it did nearly three decades ago.

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***As an aside, I DID spot this neat gif image of an Orthophonic Credenza:



OrthoFan

[larryh]

I want to thank you all for giving some very good suggestions as to where to look for issues of sound from late reproducers. I have a Columbia Viva Tonal reproducer on my 800 now that on many records with the correct volume needle play quite well. But some records just seem to powerful overcoming what seems to be a limit of the diaphragm to reproduce it without a noticeable distortion. Still the many things that now are playing well are producing some very good sound. I have a wonderful set of Delius Selections on Columbia that are so quiet you can hardly tell the surface is there. With the right needle now I can get them to produce very full sound that is pretty clear. Before I began experimenting with the insertion of the needles to obtain the best sound from the records they were overbearing in some places. I am not sure if anyone changed the gasket material at some point or not? The seller didn't know either. I am reluctant to take it apart as its doing pretty well. The original reproducer to the machine had problems and I had it rebuilt but it tends to become metallic sounding rather quickly. Years ago I rebuilt a 810 with at the time what I considered good results. I don't remember any issues with the ball bearings being disturbed. I was looking at the way the reproducers are assembled and it appears you can access the back and front by removing the covers? If that were done would it have been possible to insert new gasket's without removing the stylus bar from its pivots? From what I remember which isn't much it was a simpler job than I would have thought compared to the Credenza which as has been mentioned is difficult to take apart or work on.

[OrthoFan]

There used to be an animated gif image of an Orthophonic sound box*** that showed the correct piston action of the diaphragm...

FOUND IT!



OrthoFan

[Retrograde]

The only time a diaphragm moves that much is at the end of the 1812 Overture with the cannons!

[OrthoFan]

The only time a diaphragm moves that much is at the end of the 1812 Overture with the cannons!

LOL, very true. But, you'll notice that the very edge of the diaphragm remains relatively motionless, and that the "flexing" action takes place in the corrugated ring area. That's the way it's supposed to be working.

Unfortunately, I've seen a number of Orthophonic diaphragms in which the corrugated edge seems to have no effect, and just the very center flexes. These normally sound thin and shrill.

According to what I was told by the late Bob Waltrip, and others, the diaphragms varied in terms of quality control, especially during the later period of production when a spatter technique was used to make them. The way it was described, a mold was spattered with micro-drops of duralumin. The earlier diaphragms were made by stamping ultra-thin sheets of duralumin, but they were prone to tearing, which is why that process was abandoned. Now, whether this is all true, I don't know. I've never been able to find anything about the specific production techniques used.

OrthoFan

[Marco Gilardetti]

I was looking at the way the reproducers are assembled and it appears you can access the back and front by removing the covers? If that were done would it have been possible to insert new gasket's without removing the stylus bar from its pivots? From what I remember which isn't much it was a simpler job than I would have thought compared to the Credenza which as has been mentioned is difficult to take apart or work on.

Correct, Columbia Viva-Tonals can be serviced by removing the front and rear covers. They are about the most straightforward and easy to disassemble, which is one of the reasons why I prefer them. However, it makes no sense to change the gaskets and leave the stylus' ball bearings as they are. If you have manual dexterity enough to change the gaskets, with some patience you will also be able to rehaul and adjust the ball bearings. Here's a thread in which you may find some hints and visual directions:

http://forum.talkingmachine.info/viewto ... =7&t=23084

[larryh]

I am most pleased with the additional information you all have given. I have run off copies of the two threads for reference. My reproducer in most respects is working pretty well. I find that often its more the record as an issue in poor sound than the reproducer it self. So I am a bit hesitant to tinker with it. But what I don't know without looking is what is the condition of the rubber tubing. Does anyone have a source for the brown tubing that was suggested as the best replacement for them?

Another question here is if its possible that a bit of penetrating oil on the bearings would free them up enough to not have to take them apart. I did that on my Brunswick and I could hear a difference after a short time as to the depth of sound.

I had one reproducer rebuilt which was the original to the machine, the one I am using is a chrome one I obtained from ebay. It has more sound than the rebuilt one at this point. The rebuilt one has a noticeable metallic vibration when loud vocals or other instruments play, which the replacement so far has very little of. I was advised not to tighten the screws any farther to try and remove that as it might effect the volume and bass. Reading these suggestions it sounded like one should tighten them fully and then back off a tiny bit and check to see if there is still that metallic sound. Any other place I might check to try to prevent that?

[Marco Gilardetti]

Quite obviously oiling the bearing is better than leaving it "as is", but in turn it is not a substitute of a complete rehaul, of course. Suppose that a ball is stuck by dirt. By oiling the bearing, you might have the needlebar axle to slip over the stuck ball (which is better than a completely frozen needlebar hinge) but still the ball won't revolve in the bearing. Only by disassembling the bearing, cleaning, lubricating and chacking everything you will be sure that the needlebar is actually pivoting on a ball bearing, as it should by design.

This said, I agree that there are records which, because of wear or poor pressing, will not play well whatever you do. When adjusting a soundbox, you should use a selected set of records that are known to play well.