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Connecting tube for Graphophone BS

Posted: Mon Sep 14, 2020 12:24 pm
by fmblizz
What was the material that was used for the connecting tube for the Columbia BS? I purchased a piece of flexible metal fabric covered tubing from a forum member years ago that stated this was the correct connector and to be honest, it looked great but the sound was very, very soft and muffled but I put up with it.

Recently during these days of Covid I decided to experiment and I bought a small piece of ⅝ O/D surgical tubing and replaced the fabric covered tubing. The difference was day and night.. Not only was the sound at least twice as loud but it was also a much better/sharper quality.

I held my finger on one end of the metal tube and blew into it and it leaked like a sieve with no back pressure or resistance. This would definitely explain the sound volume difference plus all the metal flexible ridges must really play hell with the sound quality. I would think that the single most important thing for any type of connecting tube would be keeping it as airtight as possible so what I originally purchased is no way suited for this application..

Has anyone had a similar experience??
pic provided

blizz

Re: Connecting tube for Graphophone BS

Posted: Mon Sep 14, 2020 1:19 pm
by TinfoilPhono
The original was lined with rubber and a metal coil for strength and flexibility, covered in fabric. Over time the rubber breaks down, causing massive air leaks -- as you discovered.

A couple of years ago I posted about this issue: viewtopic.php?f=2&t=36010

As you can see, at the suggestion of another forum member I poured rubber cement through the tube, creating several thin layers. This sealed the leaks and created essentially a new rubber tube inside the original connector, restoring the sound volume.

Re: Connecting tube for Graphophone BS

Posted: Mon Sep 14, 2020 2:47 pm
by fmblizz
Thank you so much Rene.... this might be a job for FLEX-SEAL unless someone on this forum has a supplier for the proper material..

Blizz

Re: Connecting tube for Graphophone BS

Posted: Mon Sep 14, 2020 3:00 pm
by soundgen
fmblizz wrote:Thank you so much Rene.... this might be a job for FLEX-SEAL unless someone on this forum has a supplier for the proper material..

Blizz
Just put the surgical tubing inside , shouldn't be too difficult , Job Done !

Re: Connecting tube for Graphophone BS

Posted: Mon Sep 14, 2020 3:16 pm
by fmblizz
yep, thought of that but need to find a smaller Outside diameter tubing.. something very thing wall so it does not reduce the inside diameter too much..

thank
Blizz

Re: Connecting tube for Graphophone BS

Posted: Mon Sep 14, 2020 3:58 pm
by TinfoilPhono
My experience using a small diameter surgical tube was only moderately effective. It would need larger diameter and thin walls, as fmblizz says. The rubber cement option is easy and more effective.