The Talking Machine Forum — For All Antique Phonographs & Recordings

Inigo wrote:

Vlad71 wrote: So much to write, and not to provide not a single photo?

Sorry... A defect i must correct... I didn't take a single photo of the process... When i do these works, I'm so excited and concentrated that i forgot to take photos step by step... I promise next time i will do...

Super, your gramophone is made for the Ministry of supply of the armed forces, in other words made for the front WW2.
With respect Vlad

This poor soundbox, so tatty as you see it, is the one performing in the YouTube video. The photos show clearly the holes and tears, even the holes from the previous location of the spider nails. They seem to be opened, but they're sealed with the white plastic glue, which when dried leaves a transparent plastic film. I did it on both sides for safety. The diaphragm is completely airtight!

Sounds great in the Youtube clip, nice bass response. -I've a couple of 5A & 5B sound boxes I also want to fully strip down but am having issues finding a suitable small spanner for the lock nuts, what did you use for this?

Cheers Steve

I'm using a small wrench with numbers 4 and 5. Number 4 is the one which fits the lock nuts of HMV sound boxes numbers 4 and 5A/B.
I always start by removing the external screws. Then, a smaller screwdriver allows accessing the internal cylindric bush. I use to retain the lock nut with the wrench, or with my nail inserted between the needlebar and support, and then unscrew the bush.
Of course, first you must disengage the needlebar from the diaphragm if you are going to remove the bushes that hold the needlebar in place. For only an adjustment of the side play, you don't need to do so, given that the needlebar is going to be all the time within the two bushes.

Thanks Inigo, my diaphragms are mostly in good condition so not looking to remove the needle bar unless it’s too stiff. I did replace my 5A back (after the original one broke) with one of John Sleeps newly made replacement backs last summer, got to say this now sounds better than my two 5b’s.

I'll move to a new interesting topic raised herein...
HMV 5A & 5B soundbox differences

I did also something I've noticed improves greatly the sound, which is to relax the pressure on the diaphragm border, loosening the back screws until just the point where the soundbox is airtight, but no more.

-I had the back off my 5B last night, needle bar moves freely enough and no side play so probably no further tinkering there for now. Good call on not over tightening the back plate on re-assembly this has made a noticeable difference and gives a more fuller bass than before.

I started doing that on the HMV no.4, as I noticed I had to press quite a bit when screwing the back. So the famous 'standard' rubber joints were not always the same thickness. I discovered a good improvement in bass and sound definition when relaxing the pressure. The trick is to press just as much as needed to make the diaphragm airtight. With the stronger records it must not chatter. I test it by soft blowing by the neck; you notice if there's air leak or not. Then you fix the screws at the back with that white plastic glue, to avoid unscrewing. And for better airtightness, then you seal the joint between soundbox back and the front ring all around, using the same glue. It seals effectively, and leaves only a transparent film when dried. You can easily remove it with a toothpick. You use the toothpick to rise the film at any point, then simply pull it out...