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Orthophonic diaphragm question
Posted: Wed Aug 31, 2016 9:57 am
by wjw
I have a question for those of you that go where most fear to tread, into the Orthophonic reproducer.
Several years ago someone had new diaphragms made for these and I still see them available. I would like to know if the new ones perform just as well as the originals or should I pursue servicable oldies that are trapped in junk, crumbling reproducers? Thanks- Bill
Re: Orthophonic diaphragm question
Posted: Wed Aug 31, 2016 2:12 pm
by A Ford 1
A friend,George Epple, once indicated that he did not like the new replacement diaphragms compared to the an old one in very good condition. George rebuilds both the electric pickups and the accustical ones and has a device to re-store the magnetic properties of the horse shoe magnets of early RCA electrical pickups. Apparently, due to age most magnets do not have the flux density they had when manufactured. I also recall his saying all the vibration damping annulus inserts made to day for the Orthphonic reproducer are not created equal. These annulii are lamina of metal and rubber and I think he indicated that the rubber in some is of too high a durometer. Therefore, one wants to have an insert with the rubber durometer similar to what existed when the item was new vs the durometer of old hardened rubber.
I tried to call George earlier today but he was not at home. I will try to quize him or ask that he respond to the post.
Allen
Re: Orthophonic diaphragm question
Posted: Wed Aug 31, 2016 3:23 pm
by wjw
A Ford 1 wrote:A friend,George Epple, once indicated that he did not like the new replacement diaphragms compared to the an old one in very good condition. George rebuilds both the electric pickups and the accustical ones and has a device to re-store the magnetic properties of the horse shoe magnets of early RCA electrical pickups. Apparently, due to age most magnets do not have the flux density they had when manufactured. I also recall his saying all the vibration damping annulus inserts made to day for the Orthphonic reproducer are not created equal. These annulii are lamina of metal and rubber and I think he indicated that the rubber in some is of too high a durometer. Therefore, one wants to have an insert with the rubber durometer similar to what existed when the item was new vs the durometer of old hardened rubber.
I tried to call George earlier today but he was not at home. I will try to quize him or ask that he respond to the post.
Allen
Aha, then I have one negative vote on the new diaphragms. Thanks, Allen.
-Bill
Re: Orthophonic diaphragm question
Posted: Thu Sep 01, 2016 7:19 am
by Steve
I have rebuilt an HMV 5a soundbox (equivalent to Victor Orthophonic type) with one of the new diaphragms and it sounds perfectly fine to my fairly critical ears. I doubt anyone would be able to identify the difference but if you have a damaged diaphragm you don't have much choice anyway?
The main difference if I recall, is that the connection of the 'spider' to diaphragm is different. Whereas the originals are mechanically fixed the new diaphragms require the spider to be spot glued. Once in situ you can't see it anyway and with a resin based glue that sets quite hard, it all works absolutely perfectly.
Re: Orthophonic diaphragm question
Posted: Thu Sep 01, 2016 11:47 pm
by wjw
Thanks for your input, Steve. If there's no terrible reviews here, I guess I should try one. - bill