DD Reproducer Tuning

[neophone]

Matt,

I was wondering about the lateral motion of the DD reproducer. How tight/loose is the floating weight supposed to be? What sort of adjustments if any can someone like me make?

Regards,
J.

[Matt Brown]

John,

The weight is of course limited in it's lateral movement by the limit loop, however, what little movement it CAN make within the confines of that loop is very important to the performance of the reproducer.

The weight needs to move freely - over time, the hinge block gets dirty, oil/grease can buuld up, and it can be sluggish if not downright frozen. When this happens, you must remove the hinge block, clean it, oil, and re-install.

If you don't want to be bothered with such an undertaking, you can sometimes squirt some oil under the hinge block without taking anything apart - I consider this a temporary fix at best though.

Hope this helps.

Matt

[neophone]

Matt,

How do I do that. It seems to me (Knowing nothing about these things!) that the lateral motion of my reproducer is a bit tight. I did try to oil the tail piece and it lossed it up a tiny bit. Is it the top screw?

Regards,
J.

[neophone]

Matt,

I figured it out-I think/hope I removed the screw on the top of the tail-piece and carefully slid out the counterweight being careful of the silk thread stylus diaphragm connection. I rubbed a bit of alcohol in the pin mount and on the pin then gave the pin a VERY light buffing with 0000 steel wool. I then put some Vaseline in the hole and reassembled it. It moves much more freely now. It may be my imagination or the fact that it was the middle of the night but "Indianola" sounded a bit louder to me this time around.

Regards,
J.

[Matt Brown]

Sounds like you fixed it (or at least gave it a significant improvement) - congrats!

Matt

[neophone]

admin said:

Sounds like you fixed it (or at least gave it a significant improvement) - congrats!

Matt

;D

Regards,
J.

[maroongem]

Another important factor is to replace the rubber gaskets if it hasn't been done already. By now, these 80+ yr old gaskets will have dried out and will cause loss of bass response as the diaphragm will be loose and will vibrate too much. The later gaskets(after 1924) were made of cork, and don't dry out as much. These are seldom found though in the Standard DD Reproducer, more in the later "Dance" model of 1926 and the New Standard of 1927(later called the "Edisonic".) The stylus should have free movement horizontally on its axis, The pin that affixes it to the two "ears" should be carefully driven out and cleaned, as well as the interior shaft of the stylus bar that it goes through.

Bill

[neophone]

Bill,

Thanks, I think this reproducer has a cork diaphragm (Does it Matt?) I can see cork on the underside. The stylus bar itself seems fine, not the least bit of resistance.

Regards,
J.

[Matt Brown]

Original diaphragm (laminated rice paper w/ cork).

Matt

[steve]

Hi J,

Rebuilding reproducers is an art, when I first rebuild reproducers there was not any difference because I did not know what I was doing. Each reproducer has its problem areas and I put together an article for DD reproducer rebuilding, any comments, questions, suggestions or corrections are most welcome.

Steve

The stylus bar should almost move under its own weight on the pin, but not quite, and easily with your finger. This is one of the critical areas, too tight you loose sound volume, too loose you lose sound quality. The pins should be tight in the shoulders. The shoulder assembly that is screwed to the weight is the second style of weight, the integral ones are the third and final for the standard DD reproducer and they do not work differently. After you install the stylus bar you have to make sure it still moves freely, I do this by using a straight pin and installing the stylus bar to make sure the shoulders are not causing it to bind, then I install the pin.

There is no sound difference in a good Edison diamond and the Expert one. Today Expert uses synthetic diamonds, and a more precise cut. The big difference is the Expert pin is smaller and almost press fitted into the Expert reproduction bar and the Edison pin is larger and should fit loosely on the stylus bar. I always open up the Expert and use the original Edison pin. Expert is not perfect; I know of two of their styli that had more surface noise than theirs normally does.

Installing the new reproduction Expert stylus bar is a challenge because the original Edison stylus bar pin is 0.0272 and the new Expert pin is 0.0254 and it is practically press fitted. The new bar pin will fit loosely in the shoulders, while Edison the pin is meant to fit tight in the shoulders and loose on the bar. You want the pin fit to be so that the stylus bar almost, but not quite moves on its own weight. You will need a #70 (0.0272) and #71 (0.0254 ) drill bit and you will use the 70 by hand more as a file to make sure you don't make the hole too big. The pin that comes from Expert stylus is 0.0252 and is the size of a #71 drill bit and I believe the Edison ones are 0.0272, the size of a #70 drill bit. Expert fits tight in the bar and loose in the shoulders, that is why I drill the Expert bar out and use the original pin. I got these sizes from a micrometer at work, the actual size a 70 and 71 is supposed to be is 0.0280 for a 70 and 0.0260 for a 71.

To properly fit a new Expert bar I use a #71 drill bit on a Dremel and a #70 by hand and keep on checking. If you have a freely moving hinge block, a good stylus, a good diaphragm or a Bogantz diaphragm, the proper size gaskets (only Wyatt's sells the ones that are the same size as the ones Edison used, that I have found, others are too wide and the OD is too small) and you perfectly adjust the pin you can have a reproducer that sounds halfway between a regular and an Edisonic. Dave had pin that was too tight for his bar and he used 600 grit sandpaper to size it. I was amazed at the difference it made, when I replaced the pin with a normal one the sound was the same as a normal one.

On a DD the critical areas are hinge block movement, diaphragm condition, stylus pin fit and stylus bar movement, and compression ring tension. The next time you play a record look at how much the limit loop pin moves, if it does not move freely sound quality and volume will suffer. With the Bogantz you get better sound with the compression ring tighter. With the hinge block I remove the hinge block and then I polish the rod that goes through the body and clean and polish the area where the rod contacts inside the body, Edison must have used oil which gums up. If I use oil I use a special kind that will not gum up, oil for sleeve bearings on model electric trains. A warped diaphragm will also decrease sound quality and the Bogantz sounds best on the Edisonic. On the Edisonic reproducer the small spring that hooks up to the Edisonic stylus bar does make a difference in the sound.

I have also found you can remove the diaphragm link from the stylus bar without spreading it by taking the part that looks like a U that is attached to a bucket which holds the silk link and put the stylus bar so it touches the’ bucket’, and move it around and it comes out, some more easily than others, but you do not have to spread and then close the bar end.