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Trouble adjusting HMV 5b soundbox
Posted: Thu Jan 29, 2015 4:47 pm
by bart1927
Hi all,
When playing records I hear a lot of resonance, so I decided to try to readjust my 5B soundbox using the following instructions:
The problem is I can't seem to loosen the lock nuts (step 1). They are so close to the front of the reproducer my wrench doesn't fit. I used the smallest one I had from a "precision screwdriver set", but it's still too big. I already removed the protective grille from the soundbox to have a little more wiggle room, but it's still not enough. Are there any specialist tools I could buy? Perhaps someone can provide me with a picture (or a link) of what I need. Thanks in advance!
Re: Trouble adjusting HMV 5b soundbox
Posted: Thu Jan 29, 2015 8:41 pm
by JerryVan
You may need to grind away some of your wrench until it will fit.
Re: Trouble adjusting HMV 5b soundbox
Posted: Thu Jan 29, 2015 8:44 pm
by JerryVan
Are you sure the resonance, (buzz? or rattle?), is really generated there? If you try to wiggle the needle bar around can you feel a looseness there? The problem may be the diaphragm gaskets. Still, what you propose to try is the quickest and easiest approach and may also be remedy to your trouble.
Re: Trouble adjusting HMV 5b soundbox
Posted: Fri Jan 30, 2015 12:28 am
by Player-Tone
I had this same exact problem with my HMV 5b, what I did was create my own custom wrench by grinding out a correct size notch in a cheap little wrench with a Dremel tool. Here is a picture, you can see the notch at the other end in the handle. This worked perfectly to loosen the nuts.
PS- It's also possible that the resonance is being caused by a loose phase plug vibrating around in the soundbox throat. I would suggest making sure all the phase plug screws are tight if you haven't done so already, that might be all it is.
Re: Trouble adjusting HMV 5b soundbox
Posted: Fri Jan 30, 2015 3:34 am
by bart1927
Thanks for the advice. It seems I will have to make my own tools. A 5B has felt gaskets, so as far as I know, they can't dry out like rubber gaskets.
The reason I think some adjustment is the remedy is because I loosened the end caps a little bit, and this already caused a big improvement.
I don't know what phase plugs are, but when I remove the soundbox from the arm and shake it, I can't hear any rattling.
Re: Trouble adjusting HMV 5b soundbox
Posted: Fri Jan 30, 2015 4:08 am
by Orchorsol
Step 3 doesn't look right to me. I may be mistaken (somebody please correct) but I believe the end caps should be removed, then adjust the screws inside the threaded tube (to hold the needle bar points without play but with no force/binding), then tighten the locknuts whilst holding that adjustment in position, then replace the end caps.
Re: Trouble adjusting HMV 5b soundbox
Posted: Fri Jan 30, 2015 7:10 am
by epigramophone
Orchorsol wrote:Step 3 doesn't look right to me. I may be mistaken (somebody please correct) but I believe the end caps should be removed, then adjust the screws inside the threaded tube (to hold the needle bar points without play but with no force/binding), then tighten the locknuts whilst holding that adjustment in position, then replace the end caps.
Orchorsol is right. This is also my understanding of the correct procedure.
Re: Trouble adjusting HMV 5b soundbox
Posted: Fri Jan 30, 2015 10:36 am
by Henry
Player-Tone wrote:I had this same exact problem with my HMV 5b, what I did was create my own custom wrench by grinding out a correct size notch in a cheap little wrench with a Dermal tool.
I've used a Dermal tool, but it's a bit rough on the skin. I think a Dremel works better.

Re: Trouble adjusting HMV 5b soundbox
Posted: Fri Jan 30, 2015 10:46 am
by Player-Tone
*Lol, thanks Henry!

I will blame that on spellcheck!
Orchorsol wrote:Step 3 doesn't look right to me. I may be mistaken (somebody please correct) but I believe the end caps should be removed, then adjust the screws inside the threaded tube (to hold the needle bar points without play but with no force/binding), then tighten the locknuts whilst holding that adjustment in position, then replace the end caps.
#3 should work as is. The tube itself is not threaded, the pin is smooth and will slide in the tube after the end cap and lock nut has been loosened. the pin is only threaded on the inside where the end cap screw is inserted. By loosening the end caps only a little the pin will be free to slide inward however far the gap is until being seated in the needlebar pivot.
Re: Trouble adjusting HMV 5b soundbox
Posted: Fri Jan 30, 2015 11:03 am
by Player-Tone
Here is an illustration of a needlebar pin in the HMV No.5B: