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Brunswick 3-way reproducer issues with Pathé stylus

Posted: Sun Sep 12, 2021 1:38 am
by MTPhono
I recently purchased a Brunswick (CF) phono with a 3-way reproducer. Wyatt rebuilt as necessary and the Edison DD and 78 sections of the reproducer work well. When I attempt to play Pathé center start records with a new stylus the tone arm may play for a few seconds but soon slam to the inside of the record. Looking for any advice on tone arm setup, stylus options etc. The turntable is level so that is not the issue.

Thanks for your answers!
Scott

Re: Brunswick 3-way reproducer issues with Pathé stylus

Posted: Sun Sep 12, 2021 6:10 am
by Inigo
Maybe this is obvious for you, but in case you didn't know it... As explained by epigramophone in other thread, for playin Pathé records the counterweight must be in the position to give more weight to the needle. Also, I suppose you are trying to play Pathé records correctly... ?
The Pathé device of the Ultona is for playing vertically recorded Pathés, with a sapphire ball needle (a sapphire ended in a small spherical point, like for cyliinders, inserted in a brass shank). The more modern lateral Pathè recordings, labelled Pathé Actuelle, are indeed standard 78s for playing with standard steel or fibre needles. The vertical ones have a shallow groove, wider than the standard 78s, and if you watch the surface under a strong light, there is a shine different from standard 78s... These cannot be played with steel needles, they will ruin it, and it doesn't play well.
Could you post a short video showing your problem?

Re: Brunswick 3-way reproducer issues with Pathé stylus

Posted: Sun Sep 12, 2021 8:31 am
by CarlosV
In addition to Iñigo's comments, you should be aware that Pathé vertical records are prone to skidding, especially if there is wear on the grooves. You should also level the machine: if it slightly out of horizontal, it will play horizontal cuts normally, but Pathés will skid.

Re: Brunswick 3-way reproducer issues with Pathé stylus

Posted: Sun Sep 12, 2021 9:30 am
by Inigo
A 'modern' gramophone (post-1925) has certain geometric features in the tonearm to improve tangent tracking of the grooves. The result of that is a permanent lateral friction force on the needle towards the centre of the record. The inner wall of the grooves counteracts this force, unless you give a little slope to the machine towards the edge of the record, so it counteracts that force and the inner wall of the grooves is not pressed by the needle. This effect is not constant along the record, though, and depends on the linear speed of the surface under the needle, and the position of it on the record. How many records have needle runs near the label always towards the center.... Modern record players share the same characteristics, and are provided with a special counterweight named 'anti-skating' precisely for counteracting that lateral force. So when you install in a modern tonearm a Pathé soundbox with the sapphire ball, those shallow grooves of the Pathé records cannot counteract the latetal force and the needle skates towards the centre. The original Pathé machines had no problem, as the tonearm is a straight line from the base to the needle, which falls directly on the spindle when in the centre. These don't suffer that lateral friction forces and usually don't skate.
So if this happens with your brunswick, and everything else is ok, you should put something under the left of the machine to give it a small slope falling to the right side, trial and error, and eventually you'll get them to play properly. Any of the modern gramophones with an S tonearm should also be sloped a bit, so the inner walls of the groove don't suffer that pressure. The ideal slope would be that which causes the needle to remain in place when playing a plain (mirror-like) surface of a 12" 78 with the needle midway between the edge and the label. The record must be running at 78rpm for this adjustment...
One of those 12" one sided victrola records that has a mirror-like surface at the unrecorded side would be ideal for adjusting this anti-skating slope.
The old Victor and victrola models with the gooseneck tube don't have this problem either. They have a very bad tracking angle for 78s, though, specially at the edge of a 12" record. Their tonearms are also a straight line from the base to the needle. With that straight geometry, there is no lateral component of the friction force on the needle. S and L shaped tonearms with tracking improved are the ones with that friction component perpendicular to the diaphragm, pointing towards the left side.

Re: Brunswick 3-way reproducer issues with Pathé stylus

Posted: Sun Sep 12, 2021 1:32 pm
by MTPhono
Thanks for the advice so far! I am aware that this requires a sapphire stylus cut for the Pathé records (which I am using) and that needles will destroy these records. I'll try to provide a video. Maybe I'll just stick with a dedicated Pathé machine if these are prone to issues. It plays DDs and 78s so well I guess 2 out 3 ain't bad!

Re: Brunswick 3-way reproducer issues with Pathé stylus

Posted: Sun Sep 12, 2021 3:11 pm
by Inigo
Try the sloping to the right... , although maybe then the horn doors will fall also to the righ. .. Or tie the tonearm with a nylon thread hanging to the right side of the machine, and hang a small weight (a nut or some washers would do the trick).... You need some grams only to counteract the lateral force. In modern tonearms the antiskating is set to half the weight on the needle. For the Ultona this could be 80 grams or maybe more, but I would start with much smaller weights, incteasing it just until the point where the needle remains in the groove.

Re: Brunswick 3-way reproducer issues with Pathé stylus

Posted: Sun Sep 12, 2021 6:45 pm
by phonojim
Look on the internet for instructions for setting up the Ultona reproducer. I can't give you a link but I have seen it somewhere. I do know from personal experience that Pathé vertical cut records should play with few problems on an Ultona system.

Re: Brunswick 3-way reproducer issues with Pathé stylus

Posted: Wed Sep 15, 2021 1:22 am
by JimN
As some others have said, I had to put a couple pieces of folded up cardboard under the two left legs of my Brunswick to tilt the machine to the right to stop the reproducer from skidding across Pathé records.

Jim Nichol

Re: Brunswick 3-way reproducer issues with Pathé stylus

Posted: Wed Sep 15, 2021 5:21 pm
by alang
Here is a link to the instructions of a Brunswick Ultona: http://www.nipperhead.com/old/brult.htm

Good luck!
Andreas

Re: Brunswick 3-way reproducer issues with Pathé stylus

Posted: Thu Sep 16, 2021 1:38 am
by MTPhono
Thanks again for the assistance and now the link. I'll give it a try tomorrow.