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Thoughts on mica diaphragm peaking out to harshly.

Posted: Mon Feb 20, 2017 11:17 pm
by larryh
I am having a real time with my upright Ultona Brunswick which I have been putting up on you tube along with my Edisons and portables. It seems that first of all it plays very loudly unless I can get the smallest needle and then sometimes I have to not put it in all the way. The worst part is that on loud piano, bell and band or orchestra selections I get a very unpleasant harsh tone to the loud notes. Even if I try to dampen it down in the recording it still persist. I have noticed that using my portable Brunswick Panatrope the sound is much smoother and not so hard. But for Acoustic records its lacking a bit as well.

I rebuilt the diaphragm using new tubing and bees wax on the rear screw and some over the front foot that rest on the mica. I have tired endless adjustments to the two screws that hold the stylus bar in place. If there is something to be considering as to why its so harsh on those loud notes I would be interested to hear about any remedy. I may not have enough wax on the stylus bar where it screws to the diaphragm is one thought I had. It seems that unless the two pointed pivot screws are nearly fully tighten against the stylus bar you will get a rattle of the mica you can easily hear over the music in loud portions. I recall the Victor Repair Manual says something like tightening the pressure on the springs, which this doesnt' have, to adjust for a heavy sound or rattling. Not sure if this Brunswick Reproducer has that kind of adjustment issue.

Any ideas or advice for how I might figure this out?

Re: Thoughts on mica diaphragm peaking out to harshly.

Posted: Mon Feb 20, 2017 11:45 pm
by edisonphonoworks
It might be the weight on the arm rattling, or some other pot metal part of the tone arm. I notice this on a few of them I rebuilt too, they have very good bass response though.

Re: Thoughts on mica diaphragm peaking out to harshly.

Posted: Tue Feb 21, 2017 10:17 am
by Henry
On my Exhibition, the front gaskets were the culprits that caused the harsh sounds. When rebuilt with fresh, pliable ones, the transformation was astonishing---and with the same diaphragm!

Re: Thoughts on mica diaphragm peaking out to harshly.

Posted: Tue Feb 21, 2017 12:09 pm
by larryh
Yes Henry I did change out the gaskets and tired to use a new diaphragm, but I have to say it was terrible compared to the originals. Very low response levels to the sound. I wish the cure were that easy, I had hoped that in replacing the gaskets and renewing the bees wax and adjusting the stylus bar pivot points it would be back to normal. That used to be playing without so much of this harsh sound. Either that or after three years of daily recording I have become overly sensitive to the tones its putting out. This morning however the last record which I had posted that caused the same issues I took and played on the Columbia 800 I have next door. On that the peaks were not nearly so objectionable, so its not the record, its something to do with that Ultona Head. But what? I have gotten a few good thoughts so far, maybe something will come along that fixes it?

Re: Thoughts on mica diaphragm peaking out to harshly.

Posted: Tue Feb 21, 2017 12:18 pm
by BiliBug
While reassembling during the rebuild, did you ensure that the diaphragm was floating free on the gaskets and not touching the metal housing of the reproducer at all? It can move as you adjust the screws at the pivot point. I had that issue when I rebuilt my Ultona. I wasn't impressed with the sound quality at all, then I reassembled it again more carefully, and am now quite pleased with the difference.

Re: Thoughts on mica diaphragm peaking out to harshly.

Posted: Tue Feb 21, 2017 1:48 pm
by larryh
Yes I tired to be sure that the diaphragm was free of the side walls, although no telling if perhaps it may have moved again. That is something I can check out. I was surprised that the original diaphragms had a fair clearance space, some are much less forgiving.