1923 Rexoport soundbox

[Sir_Lunchalot]

…and one more picture, because the other one made it look a bit dirtier than it is.

[Inigo]

The diaphragm screw is usually sealed with wax. You can definitely and carefully scrap it out to remove the screw. There will be also a wax seal at the opposite side, where the needlebar sits on the diaphragm.
These seals can be removed, helping with a bit of soft heat.
It's not recommendable to move around the diaphragm while attached to the needlebar, as this can act as a lever and any small kick is amplified and the centre of the diaphragm spoiled. It's a delicate point where the mica can easily disintegrate or delaminate, and the stiffness integrity of the diaphragm being spoiled. Three diaphragm stiffness must be uniform and clean all across the surface to provide a good sound. Any bubbles, breaks or signs of delamination spoils its performance.

[Sir_Lunchalot]

Ok, thanks for letting me know. My diaphragm does have small ‘bubbles’ in one or two places around the edge. They’re barely noticeable though. I would rather keep the diaphragm original, that’s all.

[JerryVan]

Ok, thanks for letting me know. My diaphragm does have small ‘bubbles’ in one or two places around the edge. They’re barely noticeable though. I would rather keep the diaphragm original, that’s all.

The slight delamination at the edges is no problem at all and better than a lot of examples.

To size the gaskets, just place a length of gasket material in the reproducer and mark a spot maybe 3/32" past the overlap at the end of the gasket hose. Cut it there to make the hose a little extra long, as I mentioned in my previous post.

[Sir_Lunchalot]

Ok, thanks for letting me know. My diaphragm does have small ‘bubbles’ in one or two places around the edge. They’re barely noticeable though. I would rather keep the diaphragm original, that’s all.

The slight delamination at the edges is no problem at all and better than a lot of examples.

To size the gaskets, just place a length of gasket material in the reproducer and mark a spot maybe 3/32" past the overlap at the end of the gasket hose. Cut it there to make the hose a little extra long, as I mentioned in my previous post.

Thanks for that. I actually just went ahead with re-doing the gaskets after I asked, and I’m pleased to say that I used that exact method. I’m glad that you replied though, as you’ve confirmed that I did it right.

I gave the gramophone a test run on my few acoustic recordings, and I’m happy to report that it plays very well now! I think it may be slightly quieter now, but the tone is that much softer (less harsh I mean) and ‘fuller’ than it was previously. Overall, despite the comparatively tiny horn, it does sound very nice!

Thanks for the help and advice Jerry, and also from everyone else that has chimed in here. I really appreciate it!

Thanks again,
William

[JerryVan]

Thanks for the help and advice Jerry, and also from everyone else that has chimed in here. I really appreciate it!

Thanks again,
William

Happy to help, and happy for the outcome.

[Inigo]

Enjoy that marvel!

[Sir_Lunchalot]

I hate to revive forum threads like this, but I have just one more question for you.

I have tested the soundbox on about 5 or 6 acoustic recordings at this point, and it handles them well. It even got through the most demanding parts of Gershwin’s 1924 recording of ‘Rhapsody in Blue’ without faltering.

The problem comes when I try to play a particular record. It is a 1920s repress of a 1911 recording, and is nothing out of the ordinary (just baritone with orchestral accompaniment). In two places (you can see them on the record, the grooves are pretty intense there) during the song, the gramophone really struggles, and slows down quite noticeably for a moment.

I have cleaned the record thoroughly with a damp cloth, but I haven’t done anything like using detergent. The record looks immaculate, the needle is not dirty after playing, and I don’t believe that the record is particularly worn (my HMV 102 plays it perfectly).

The only thing that I can think of that has the remotest possibility of being the problem is this: I have discovered that the soundbox is not perfectly tight where it meets the tonearm. It has a very small, but still noticeable amount of ‘play’ from side to side. I have no idea if that would affect its compliance at all, but I would like to fix it. I read of someone using plumber’s thread tape to make the connection a bit better, and when I get a chance (away currently) I think I’ll give that a try.

If any of you have any ideas about the problem, I’d be glad to hear them.

Thanks,
William

[JerryVan]

William,

This has nothing to do with the reproducer itself.

Passages with more intense volume require a bit more power to play through. Even with a record, needle, & reproducer in good condition, these "energetic" grooves can slow down the turntable. It's sometimes a function of a motor not wound fully enough to power through, or mainsprings that are weak, or even the record slipping a bit on the turntable. It may also be exacerbated by the rubber isolator having become hardened. (The isolator is the rubber flange that your reproducer mounts to with the 3 screws.) And yes, record wear or using a worn needle can add to the load as well. As to groove wear, these intense grooves typically are the first to wear due to the higher energy they need to impart upon the needle.

[Inigo]

Ok with all things said. The problem is a weak motor. The motor is the only energy source for playing the record. The record is only like a very complex cam wheel which transforms the motor rotation movement into sound vibrations...