Is it possible to save this gramophone? (looking for advice)

[tipex]

Hello!

I'm new to this forum and to the gramophone world (although I've always been a vinyl enthusiast and a collector).
Some weeks ago I saw a gramophone in a thrift shop in very bad shape. As the turntable still spun, I thought to give it a chance and took it home with me.
The gramophone had clearly been stored in a garage or shed for several years... The wood needs a complete restoration, the front door is missing, all metal parts were faded and dust was everywhere...

I read a little bit and I found that it is a Sonora Prelude, from the 1920s.
Prior to a future restoration (if worth it), I cleaned the wood and polished the metal parts. I also added some sewing oil and grease to the motor (which was made in Switzerland by 'QR' ??)

I tried the needle that came with it -I have some 78s- and it sounded horrible, full of distortion.
I bought some new steel needles and the sound was much better. Night and day. However, there's still some distortion on some records, mostly on loud parts. It's like the soundbox resonates on some frequencies and distorts the sound. It sounds however a little bit better with the top wooden lid closed.
This also tends to happen more at the end of the record (as the needle approach the center of the disc).

The problem is that the soundbox (Sonora Reproducer Num 5) is in very bad shape. It's full of cracks and some parts are missing (you can see the photos below). Also, the diaphragm doesn't look good (a little bit bulky). A paper seal broke off when dismantling the soundbox (honestly I thought that the whole soundbox would break apart).
I thought about repairing the soundbox with a metal epoxy putty and building a new diaphragm from an aluminum can (but that looks a little bit more complicated).

Have you faced any issues like this?
What would you recommend me to do?

Thanks in advance!

[Django]

The impossible just takes a little longer. Some machines are a labor of love. It often depends more on how much effort you want to put into it.

Not many of those late Sonora reproducers survived. I would start with the reproducer. If you can fix or replace it, then you are off to a good start. Without a reproducer, it’s not a phonograph.

You could put a want add in the Yankee Trader on the forum and search eBay for a replacement.

[broso252]

The swollen potmetal of the reproducer may be allowing the diaphragm to vibrate somewhere around the edges. If it uses a gasket to seal the diaphragm you may be able to use a thicker rubber gasket to get it to press down everywhere around the edge.
The other potential problem may be in the pivot for the needle bar. It may use rubber parts that have probably hardened over time.
Hopefully they used some reversible method of attachment between the diaphragm and the needle bar as this would make checking the needle bar pivots much easier.
You may be able to get a few of the dents out of the diaphragm. I use a mechanical pencil for this purpose as it has a fine tip and the pencil lead doesn't seem to scratch. I probably don't need to tell you to be careful when doing this as its very easy to add more dents.
Make sure you always change the needle after every side of a record to avoid extreme record wear.
You may be able to make a wanted ad for one of these reproducers in better shape on on the one of the trader sections of the forum or from someone who sells phonograph parts.
Depending on your location, you may be able to get an older Victrola or other model with no bad potmetal for around $100 and it would likely only need some rubber gaskets replaced and some cleaning.

[gramophoneshane]

I also added some sewing oil and grease to the motor (which was made in Switzerland by 'QR' ??)

Just so you know, Sonora got all their parts (motor, tonearm, soundbox, brake, speed indicator) from Paillard's in Switzerland, and the "QR" is actually the model designation for that style of motor.
Sonora continued to use Paillard gramophone parts even in their early radiogram combos, which were put into American made cabinets.

[OrthoFan]

The Sonora Prelude -- https://www.collectorsweekly.com/storie ... gramophone -- is a nice little model, and would be worth restoring. In addition to the sound box, the biggest issue is the missing door. Depending on your cabinet making skills, a reproduction would probably work.

As for the sound box, the dented diaphragm might contribute to the distortion you hear, but if you work carefully, it's possible to restore the original shape, as noted. Another culprit would be the needle-bar pivot. Considering the condition of the sound box's shell, even a slight adjustment to the screws might cause it to crumble apart. I think hunting down down a good condition replacement would probably be the best bet--not necessarily a Sonora sound box, but one with matching specs (aluminum diaphragm, etc.) designed for playing electrically recorded records, such as the type used on 1930s/1940s portable phonographs.

OrthoFan

[Inigo]

I bet for the needlebar pivot too. That diaphragm is dented, but looks good, it should sound well despite these small dents. It's a Maestrophone Paillard diaphragm, similar to all later Paillard soundboxes. Try to disassemble it from the needlebar, carefully, as there is a very tiny screw there. Be careful not to spoil the central hole for the screw in the diaphragm dome. You must remove the sealing wax first, and the screw is below. You can use, carefully, a toothpick for this.
Once removed, try to disassemble the needlebar pivot. If Paillard, this could be a simple flexible copper plate squeezed between steel plates and screws at both sides. Maybe the screws are loose, and this is the only problem.
Next, try to improve the seating of the diaphragm edge between the front ring and backplate. The paper gaskets should be at both sides. You can easily reproduce new gaskets from suitable thick paper. If the soundbox is somewhat out of shape as it seems, use felt gaskets instead of paper. Anyway, this shouldn't neither be a big problem for good sound, provided the space between diaphragm and backplate is airtight. There is where air pressure is generated, and must not go out except by the central outlet to the tonearm. If the ring is deformed and the backplate is straight, you'll need thicker gaskets to fill in properly for this purpose. The problem here could be that the screws are too short .. I'll study your photos deeper and tell you more....
You've already separated the diaphragm and needlebar from the front ring!

[BillH_NJ]

Good luck with the reproducer. I have the Sonora Concert from the same year and it’s a nice machine. Its reproducer is in slightly better shape but still showing some deterioration of the potmetal. I also have a Philharmonic from 1927 with basically the same reproducer but marked as 5B and with a slightly different diameter mount that matches the size of the Victor Orthophonic mount (so the reproducers are not interchangeable between the Concert and the Philharmonic).

I knew that Sonora sourced from Paillard, but does that mean that Paillard reproducers would fit on the Sonora Reproducing phonographs? It looks like they changed the size for the Tonalic machines the next year. I am trying to see what options there might be for these models if the Sonora reproducers are hard to find.

As you found, the reproducers seem to be the weak point after 100 years. The rest seems to be in good condition and well worth keeping.

Bill