HMV number 21 soundbox

[poodling around]

Two things puzzle me though. Firstly, the one I have has a different inscription on the reverse side - it only has the patent number and not the HMV model number. (I can't find the patent on-line either). Maybe this is an early one ?

I have two HMV 97s, a green and a black. The green ones' 21 soundbox has simply "Made in England" on the back, and the black ones' has nothing at all, completely plain. As the 21s were also used on the Columbia 204 (numbered 15A) could it have been more logical to remove all markings on the backs so that they could be used for both machines? It would seem logical, as some of the 204s I have also have also have plain backs to the soundboxes. If so, then that would indicate that the one pictured by emigramophone (above) is an early version, and yours and mine are later.

Barry

Thinking a bit more, being interchangeable may mean nothing as most gramophones were HMV 101 or 102 tone-arm size irrespective of make ? Maybe ?

[Phono48]

[

Maybe. But the HMV one has the dog and the columbia one the musical note. So, inter-changing would not have bothered them ?

The only difference is the front mask, the rest of the soundboxes are identical. So as far as the manufacturing process was concerned, if the backs had been marked with anything pertaining to either HMV or Columbia, then two separate backs would have to be made. Therefore it would have been more economical to have a plain back that could be used for either soundbox. No?

Barry

[poodling around]

[

Maybe. But the HMV one has the dog and the columbia one the musical note. So, inter-changing would not have bothered them ?

The only difference is the front mask, the rest of the soundboxes are identical. So as far as the manufacturing process was concerned, if the backs had been marked with anything pertaining to either HMV or Columbia, then two separate backs would have to be made. Therefore it would have been more economical to have a plain back that could be used for either soundbox. No?

Barry

Aha ! Yes, I see it now.

As the only difference was the front piece they could manufacture a quantity of the main body (with just the patent number) and supply the front part according to demand.

Thanks Barry - very good indeed.

[Phono48]

As the only difference was the front piece they could manufacture a quantity of the main body (with just the patent number)

Or, as in the case of the one on my black 97, not even a patent number!

Barry

[poodling around]

As the only difference was the front piece they could manufacture a quantity of the main body (with just the patent number)

Or, as in the case of the one on my black 97, not even a patent number!

Barry

Ha ha - that made me laugh ! I had forgotten about that.

So you actually have an early one and I have a late one - that can't be right lol !

[anchorman]

I imagine they did that with the backs for the reason barry postulates here. I've not seen one of this style soundbox that had any pot metal on it all brass. There is a different, cheaper one that came with the G-50 and some other columbia japan portables, along with a number of european machines. I think it was originally a Pathé perhaps a design from germany or switzerland? or maybe one of those others took it up after columbia/hmv designed it. chromed (steel?) front, pot metal back, similar pivots, but needle bar not interchangeable as far as I can remember. The one on my japanese G50 was rotted away, and I 3D printed a new back for it, which worked ok. I could dig it out and post a picture later tonight.

Not sure if the diaphragms changed or not. The american viva-tonal was smooth at the edge past the center of the cone, the 15 has radial curved embossing around the edge similar to the number 9. The center of the diaphragm was spun on all of the brass versions I've seen of the 15/viva tonal variants, and connected to an outer, more flexible, stamped ring using 3 small tabs, and possibly some sort of glue at the joint. the tabs on mine were sealed with beeswax.

I'm very curious to know what specific differences there are between the american "viva-tonal", and the 15, 15a, and 15b. I've been told that there are two different screw patterns on the various 15 models, with one having the mirrored position of the internal screws vs the outer facing screws on the rubber tone arm isolator. The american viva-tonal uses thin screws, vs. the fat screws used on the 15's that I have seen.

[anchorman]

I think they were a cheap soundbox for cheap machines.
They used pot metal in their construction, and one of mine has swollen enough to crack the chrome plated mask/front where it forms the narrow edge of the body.
Mine both sound fairly good in my opinion, but not as good as a 5a/b.
If I remember correctly they fit the same size tonearm as a No.4.

I think this one you describe is the same as the cheesy pot metal one that was on my G-50. Not at all in the same league as the HMV-21 or the original columbia 15 variants.

The american viva-tonal uses bigger screws on the needle bar, and the needle bar looks to have been made on a dirt floor in a cave somewhere. the triangle cut for fibre needles is rotated the wrong way, and the hole in general is off center. The needle bar saddle to hold the pivot screws is permanently attached on the viva-tonals, vs held on by screws on the 15. The needle bar and the saddle (what is this actually called) are identical with the columbia number 8, and look to be 100% interchangeable. The needle bar on the American viva tonal that I have is missing the bend at the diaphragm screw attachment, and doesn't fit inside the case properly. I'm astounded that they bothered to sell such a terribly made piece. I know of two other viva-tonals that upon inspection probably suffer the same defects as the one I have.