HMV 163 gramophone. - UK Vintage Radio Repair and Restoration Discussion Forum

B.Taylor · 27th Nov 2021, 3:46 pm

Hello,

I have an HMV 163 which I have been restoring over the past few months.
I definitely do not have any air leaks and know the soundbox is in good order but It is not producing the same volume or bass as my friend's 163.

I have removed the connecting tube between the tone arm and horn and can see that the inside of the horn is coated in an oxide. My question is could this slightly rough surface be damping the sound?

Thanks, Bill

Phonosandradios · 27th Nov 2021, 6:48 pm

Hi
I also have a 163. Congrats as although they are the smallest of the re-enterant models they give a great sound. My only complaint with mine is that it is too loud! I have to use either soft tone steel needles or I used to find that thorn needles work really well and give a very pleasant tone without the harshness of steel. Things to check though are have you tried a different HMV soundbox to make sure your problem isn't that? These have a pot metal back which can crack and distort - although I have yet to find one that is so bad that it produces poor sound. Have you checked that there is no other damage to the soundbox. It would be useful to rule out an issue with the soundbox first.

If the soundbox is ok then another possibility is an air leak somewhere. Check between the tone arm and where it joins into the horn. A good seal of thick grease at this point can really help. Whilst these have metal horns the weak point can be the seams on the horn particularly if there has been any corrosion leading to a small failure somewhere - can be very difficult to spot though. A guy I knew once took their horn out and filled it with water to find all the leaks! I am not suggesting you do that but it just shows the extremes that some will go to find find a leak.

Any leaks on the horn can easily be sealed with silicone.

If there is loose oxide on the inside of the connecting pipe I would wipe it off to see if that helps. After all the sound is best transmitted along a smooth conduit. The other thing I would check is that nothing has been stuffed up (or down) the horn to muffle it. As I said these machines have great volume particularly when used with steel needles. A sock or something similar my be hiding down there somewhere. Let us know how you get on.

Audio1950 · 27th Nov 2021, 8:50 pm

As said above, the problem may be that someons has taken the front grille off and pushed something in to muffle the sound. I read recently that the same problem was caused by someone having lined the horn with carpet! A problem can also arise when the needle bar pivots have become stiff, sometimes caused by hardened oil or grease, or often when the pot metal back of the soundbox has distorted and thrown the front of the soundbox and the pivots out of line. The needle bar must be free to move in and out very freely, but with no side-to-side play. Stiffness in the needle bar will also damage your records!

Barry

B.Taylor · 28th Nov 2021, 4:00 pm

Thanks both for your replies,

The sound box is definitely ok. I have tried my friend's soundbox from his 163 and there was no difference. The tone arm joint is well sealed with grease.
It is interesting to learn that the seams on the horn can leak. As there is a lot of corrosion on mine this could be the problem. I will remove the horn and thoroughly check it over and also be sure nothing has been pushed right inside.
I will report back. It will be a while though as really busy with work at the moment.

27th Nov 2021, 3:46 pm	#1
B.Taylor Tetrode Join Date: Feb 2020 Location: Cheltenham, Gloucestershire, UK. Posts: 82	HMV 163 gramophone. Hello, I have an HMV 163 which I have been restoring over the past few months. I definitely do not have any air leaks and know the soundbox is in good order but It is not producing the same volume or bass as my friend's 163. I have removed the connecting tube between the tone arm and horn and can see that the inside of the horn is coated in an oxide. My question is could this slightly rough surface be damping the sound? Thanks, Bill

27th Nov 2021, 6:48 pm	#2
Phonosandradios Tetrode Join Date: Dec 2020 Location: Trowbridge, Wiltshire. Posts: 69	Re: Hmv 163 Hi I also have a 163. Congrats as although they are the smallest of the re-enterant models they give a great sound. My only complaint with mine is that it is too loud! I have to use either soft tone steel needles or I used to find that thorn needles work really well and give a very pleasant tone without the harshness of steel. Things to check though are have you tried a different HMV soundbox to make sure your problem isn't that? These have a pot metal back which can crack and distort - although I have yet to find one that is so bad that it produces poor sound. Have you checked that there is no other damage to the soundbox. It would be useful to rule out an issue with the soundbox first. If the soundbox is ok then another possibility is an air leak somewhere. Check between the tone arm and where it joins into the horn. A good seal of thick grease at this point can really help. Whilst these have metal horns the weak point can be the seams on the horn particularly if there has been any corrosion leading to a small failure somewhere - can be very difficult to spot though. A guy I knew once took their horn out and filled it with water to find all the leaks! I am not suggesting you do that but it just shows the extremes that some will go to find find a leak. Any leaks on the horn can easily be sealed with silicone. If there is loose oxide on the inside of the connecting pipe I would wipe it off to see if that helps. After all the sound is best transmitted along a smooth conduit. The other thing I would check is that nothing has been stuffed up (or down) the horn to muffle it. As I said these machines have great volume particularly when used with steel needles. A sock or something similar my be hiding down there somewhere. Let us know how you get on. Last edited by Phonosandradios; 27th Nov 2021 at 6:58 pm. Reason: update advice

27th Nov 2021, 8:50 pm	#3
Audio1950 Dekatron Join Date: Nov 2008 Location: Whittlesey, near Peterborough, Cambridgeshire, UK. Posts: 3,761	Re: Hmv 163 As said above, the problem may be that someons has taken the front grille off and pushed something in to muffle the sound. I read recently that the same problem was caused by someone having lined the horn with carpet! A problem can also arise when the needle bar pivots have become stiff, sometimes caused by hardened oil or grease, or often when the pot metal back of the soundbox has distorted and thrown the front of the soundbox and the pivots out of line. The needle bar must be free to move in and out very freely, but with no side-to-side play. Stiffness in the needle bar will also damage your records! Barry

28th Nov 2021, 4:00 pm	#4
B.Taylor Tetrode Join Date: Feb 2020 Location: Cheltenham, Gloucestershire, UK. Posts: 82	Re: Hmv 163 Thanks both for your replies, The sound box is definitely ok. I have tried my friend's soundbox from his 163 and there was no difference. The tone arm joint is well sealed with grease. It is interesting to learn that the seams on the horn can leak. As there is a lot of corrosion on mine this could be the problem. I will remove the horn and thoroughly check it over and also be sure nothing has been pushed right inside. I will report back. It will be a while though as really busy with work at the moment.