WANTED: Replacement HMV 5A / 5B backs

[Jwb88]

Does anyone still make/supply replacement backs for HMV 5A or 5B soundboxes? The fact that so many are swollen or showing signs of aging is worrisome. I knew there were aluminum replacements out there at some point, are they still available?

Thanks,
-John

[epigramophone]

https://www.windupgram.co.uk/replacemen ... und-boxes/

[CarlosV]

https://www.windupgram.co.uk/replacemen ... und-boxes/

The shortcoming with these replacement backs is the absence of the place to fit the rubber ring. When connected directly to the arm, the compliance provided by the rubber ring is lost, creating a high load on the record groove (and increased wear), as well as eliminating the acoustic damping provided by the rubber ring. I have experienced the beneficial effects of the rubber ring everytime I replaced a hardened one with a new ring. The acoustic effect is clearly noticeable, as well as the reduction in record wear.

[gramophone-georg]

https://www.windupgram.co.uk/replacemen ... und-boxes/

The shortcoming with these replacement backs is the absence of the place to fit the rubber ring. When connected directly to the arm, the compliance provided by the rubber ring is lost, creating a high load on the record groove (and increased wear), as well as eliminating the acoustic damping provided by the rubber ring. I have experienced the beneficial effects of the rubber ring everytime I replaced a hardened one with a new ring. The acoustic effect is clearly noticeable, as well as the reduction in record wear.

This.

It's quite unfortunate that this replacement is made like this. Totally ruins the whole exercise.

[Jwb88]

Thanks for the info. Interesting.

Have no idea why it’s made all in one piece. Although, considering the back flange I have is completely rock hard, I’m still considering one, LOL.

[phonosandradios]

I have one of these new backs and must admit that I didn't realize when I bought it that it didn't have the rubber isolator or a space for one. I have yet to fit it for the reasons highlighted above about sound and record wear. If you are going to the trouble of replicating the back it seems a huge oversight not to of incorporated it in the design in my opinion.

[CarlosV]

Thanks for the info. Interesting.

Have no idea why it’s made all in one piece. Although, considering the back flange I have is completely rock hard, I’m still considering one, LOL.

If the problem wih your soundbox is only the hardened rubber back, there are good replacements for sale. Removing the old one is tricky and requires patience, but can be done.

[Inigo]

See my post in
viewtopic.php?f=11&t=46940&p=278563#p278563
The backplate fail can be ammended with a lathe...

[JerryVan]

As Inigo suggests, anyone with access to a metal lathe can bore the hub to allow the rubber isolator to fit. I realize however, that might not be just anyone. Still, a solvable issue. Best to buy them while they're available and look into the other issue later.

[soundgen]

I've dug around and found four original No 5B backs in usable condition all flat with no cracks . they are the same price as the new aluminium backs £30 + post

I've listed one on eBay

viewtopic.php?f=14&t=47200

the first bid secures if I am around to sell when it happens !

the other 3 are pictured here , the brass back has no model number on and has had the venturi removed but this can be replaced by one from a broken part , the brass backs are bizarrely very rare and I don't know why they were made

There are two insets which will go with the first ones sold

email rather than PM as the PM doesn't get sent on