Credenza adjustments

[gregbogantz]

Sean, I didn't comment on this subject earlier because it didn't make a lot of sense to me and it has not been my experience. Also, I thought it probably had mostly to do with individual users' experience, and YMMV, and I didn't want to start an argument about it. I've never paid much attention to the flexibility of the rubber bits used on reproducer mounting flanges because my impression is their main purpose was to provide an air seal. Also, they provide some shock absorber function to protect the diaphragm from cracking in case the user slams the needle into the record. But my experience is mostly limited to the larger, later reproducers with higher compliance in their diaphragm and vibratory systems. And I use only soft tone needles since I consider a loud tone needle the equivalent of an unyielding nail and it's use tantamount to a first degree murder sentence on a record. Due to the fact that it does not flex.

So, yes, compliance in the diaphragm and needle system is absolutely necessary to produce good reproduction as well as minimal record wear. But this compliance should be occuring in only the diaphragm and needle linkage. I don't expect that the reproducer should be wobbling on the tone arm mount as could happen with a soft mounting flange. When this happens, the reproducer mass is mechanically decoupling from the tone arm mass and resonating at a much higher frequency than it should. This causes the bass response to fall off drastically below this resonant frequency. It is, therefore, undesirable from a reproduction fidelity point of view. So, under the most desirable condition, there should be sufficiently high compliance in the desired vibratory system that the reproducer should not be encouraged to flex on its tonearm mount. This should be the result of using a properly rebuild reproducer with soft gaskets on the diaphragm or a properly flexible diaphragm such as an orthophonic, and soft tone needles which themselves flex during playback.

Having said that, I suppose if one were to use stiff loud tone needles with a small, low compliance reproducer design like a Victor Exhibition or even earlier and smaller Concert model, you would likely encourage reproducer flexing at the tonearm mount if you played a loud record with a lot of bass content such as an electrically recorded one. This would be a bad situation and would likely cause serious mistracking due to the poor system compliance which would likely cause record wear, especially if the mounting flange was hardened and not flexible. But it's not something that I would consider doing, nor would I encourage anyone else to do it.

Most of my listening is with the newest Victor orthophonics or my own reproducer designs which have much higher compliance than even the Victor. I have them mounted purposely rigidly to the tonearm for the very reason that I want the tonearm resonance to be as low as possible to provide the best bass reproduction. With the tonearm bearings sufficiently lubricated so that there is low tracking friction, I have not noticed undue record wear caused by having an unyielding coupling between the reproducer and the tonearm. Just good bass thru the large orthophonic horn.

So, again, YMMV depending on your preferences in machines, records, and needles.

[OrthoSean]

I appreciate your input, Greg! I'm not interested in arguments, either, but it's always nice to share experiences here about things that at least I think will help make our machines perform their best. My main point is pretty simple, replace these old dried out rubber parts with new, more flexible ones, and adjust everything properly and record wear will be reduced by far.

I agree with you about loud needles, I almost never use them, a soft or half tone on an orthophonic machine is generally more than sufficient. I will occasionally throw a loud needle in for demonstartion puropses, but I don't use them for casual listening at all.

Sean