HMV No:4 Soundbox question.

[poodling around]

That is indeed pot metal. Clearly the "guide" I read about is not infallible.

Aha ! Thanks very much indeed for confirming.

That is the good thing about gramophone collecting - there is always something new to learn.

I don't feel so bad about destroying a pot metal No. 4 soundbox now

[Phono48]

It's very easy to swap the inserts from one soundbox to another, I've done it myself when the rubber on a pot-metal back had gone rock hard. I've also seen a couple of instances where a No.4 with the flat rubber insert has been advertised as "brass backed" but the milling round the edge of the back clearly showed that it was pot metal. Naughty!

Barry

[leels1]

Also be careful with the screws holding the back plates on, I’ve found they can sometimes be really tight and almost welded in. When you try and unscrew them they snap as they’re very thin brass. It’s really annoying to drill them out the brass front bezel.
Some penetrating oil does help to free them up!

[OrthoFan]

When making the adjustments to the needle bar pivot, this is a good guide: https://www.nipperhead.com/old/vic4sb.htm It's identical to the HMV #4 sound box.

Here are the basic/easy steps explained to me several years ago.

Keep in mind the collar is not threaded and moves in and out. If it seems frozen, apply some penetrating oil to the area. To test for side play, try moving the needle bar in the direction of the pivot screws. If you feel a sideways movement, repeat the above steps, since side play can cause buzzing or blasting. The needle bar should only move in the direction required to track the record's groove.

HTH,
OrthoFan

[Inigo]

The rubber collar can confuse, for I've seen rubber collars of the protruding type being snap cut so they lose the overlapping part and the rest remains inside, resembling the flush type.

[poodling around]

It's very easy to swap the inserts from one soundbox to another, I've done it myself when the rubber on a pot-metal back had gone rock hard. I've also seen a couple of instances where a No.4 with the flat rubber insert has been advertised as "brass backed" but the milling round the edge of the back clearly showed that it was pot metal. Naughty!

Barry

You are almost making me lose faith in humanity there !

Are the brass backed ones entirely solid brass I wonder ?

[poodling around]

Also be careful with the screws holding the back plates on, I’ve found they can sometimes be really tight and almost welded in. When you try and unscrew them they snap as they’re very thin brass. It’s really annoying to drill them out the brass front bezel.
Some penetrating oil does help to free them up!

Interesting. Now you mention it, I did notice that the screws were made of brass and therefore a little 'soft'.

Penetrating oil !!! I wish I had thought of that ! I bet that would have been very good to loosen the back.

Great advice, thanks leels1

[poodling around]

When making the adjustments to the needle bar pivot, this is a good guide: https://www.nipperhead.com/old/vic4sb.htm It's identical to the HMV #4 sound box.

Here are the basic/easy steps explained to me several years ago.

No 4 Sound Box Pivot.jpg

Keep in mind the collar is not threaded and moves in and out. If it seems frozen, apply some penetrating oil to the area. To test for side play, try moving the needle bar in the direction of the pivot screws. If you feel a sideways movement, repeat the above steps, since side play can cause buzzing or blasting. The needle bar should only move in the direction required to track the record's groove.

HTH,
OrthoFan

Very interesting and helpful.

Thank you OrthoFan.

[poodling around]

The rubber collar can confuse, for I've seen rubber collars of the protruding type being snap cut so they lose the overlapping part and the rest remains inside, resembling the flush type.

Interesting. Maybe that is what happened to mine many years ago.

I suppose using a needle to scratch the back of the soundbox may be a good test ?

[Inigo]

Generally the brass backplates are easily detected at the edges where the black painting gets worn and shows the metal below.