Cracked Orthophonic Reproducer
- travisgreyfox
- Victor IV
- Posts: 1157
- Joined: Sat Aug 12, 2017 9:25 pm
Cracked Orthophonic Reproducer
So has anyone repaired a cracked up pot metal reproducer and made it sound good? If so what was used to fill in the cracks?
-
- Victor Monarch Special
- Posts: 5346
- Joined: Mon Aug 24, 2009 3:08 pm
- Location: Southeast MI
Re: Cracked Orthophonic Reproducer
Travis,
Depends on how badly they're cracked. I have rebuilt ones with a fair amount of "crackle" and have let the "wicking" variety of Loc-Tite, http://www.criticaltool.com/loctite-290 ... readlocker soak into the crackled surface, thinking that it would harden and stabilize the structure. In all reality however, that's probably wishful thinking. For gaping cracks, I guess you could carefully fill them with JB Weld, or some other epoxy based filler with metallic particles mixed in.
The reproducers that seem to have stable caps, but swollen backs and split retaining rings seem to hold a bit more promise, assuming you can reuse the back plate and have a good retaining ring. The problem is, while the caps may appear nice yet, the swollen back plate has stretched the cap open such that a good retaining ring will be rattling loose in the cap. It's even worse when the cap has split too. Some have placed thin strips of aluminum foil in the cap, to take up enough space so that the ring will thread in and stay put. I've done that too, but used paper, and had fairly good results. The other issue with swollen caps is that the increased diameter of the cap essentially causes the needle arm to become too short to properly reach the center of the diaphragm. You'll see badly swollen reproducers with the diaphragms distorted by the needle arm pulling on them as the swelling draws the bearing block ever farther away from the diaphragm center.
Aren't brass reproducers nice...
Depends on how badly they're cracked. I have rebuilt ones with a fair amount of "crackle" and have let the "wicking" variety of Loc-Tite, http://www.criticaltool.com/loctite-290 ... readlocker soak into the crackled surface, thinking that it would harden and stabilize the structure. In all reality however, that's probably wishful thinking. For gaping cracks, I guess you could carefully fill them with JB Weld, or some other epoxy based filler with metallic particles mixed in.
The reproducers that seem to have stable caps, but swollen backs and split retaining rings seem to hold a bit more promise, assuming you can reuse the back plate and have a good retaining ring. The problem is, while the caps may appear nice yet, the swollen back plate has stretched the cap open such that a good retaining ring will be rattling loose in the cap. It's even worse when the cap has split too. Some have placed thin strips of aluminum foil in the cap, to take up enough space so that the ring will thread in and stay put. I've done that too, but used paper, and had fairly good results. The other issue with swollen caps is that the increased diameter of the cap essentially causes the needle arm to become too short to properly reach the center of the diaphragm. You'll see badly swollen reproducers with the diaphragms distorted by the needle arm pulling on them as the swelling draws the bearing block ever farther away from the diaphragm center.
Aren't brass reproducers nice...
- travisgreyfox
- Victor IV
- Posts: 1157
- Joined: Sat Aug 12, 2017 9:25 pm
Re: Cracked Orthophonic Reproducer
wow, what a pain. You would think with the demand and the high prices that someone would make a reproduction orthophonic reproducer. Maybe as 3D printing technology gets better we will see one.
- alang
- VTLA
- Posts: 3115
- Joined: Thu Aug 19, 2010 9:36 am
- Personal Text: TMF Moderator
- Location: Delaware
Re: Cracked Orthophonic Reproducer
You can buy reproduction orthophonic reproducer fronts and backs from Ron Sitko and others. The only thing I think is not being reproduced is the needlebar.travisgreyfox wrote:wow, what a pain. You would think with the demand and the high prices that someone would make a reproduction orthophonic reproducer. Maybe as 3D printing technology gets better we will see one.
Andreas
- travisgreyfox
- Victor IV
- Posts: 1157
- Joined: Sat Aug 12, 2017 9:25 pm
Re: Cracked Orthophonic Reproducer
Yeah. It would be great to just be able to buy one already put together and ready to play then deal with the delicate process yourself though.alang wrote:You can buy reproduction orthophonic reproducer fronts and backs from Ron Sitko and others. The only thing I think is not being reproduced is the needlebar.travisgreyfox wrote:wow, what a pain. You would think with the demand and the high prices that someone would make a reproduction orthophonic reproducer. Maybe as 3D printing technology gets better we will see one.
Andreas
Maybe one day we will see nice new soundboxs being sold.
- De Soto Frank
- Victor V
- Posts: 2687
- Joined: Wed Dec 01, 2010 1:27 pm
- Location: Northeast Pennsylvania
Re: Cracked Orthophonic Reproducer
Apparently, one of the difficulties of replacing parts on original pot-metal Orthophonics is that VTM used several different thread pitches for the spanner-ring, according to Ron Sitko. ( And I have no reason to doubt him. )
So, buying a matched front & back would be the way to go...
I have a couple of "garbage" Orthos ( pot metal is beyond salvation ) that I am keeping for their diaphragms and needle-bars; someday I hope to get a couple repro bodies and do some transplants.
So, buying a matched front & back would be the way to go...
I have a couple of "garbage" Orthos ( pot metal is beyond salvation ) that I am keeping for their diaphragms and needle-bars; someday I hope to get a couple repro bodies and do some transplants.
De Soto Frank
-
- Victor Monarch Special
- Posts: 5346
- Joined: Mon Aug 24, 2009 3:08 pm
- Location: Southeast MI
Re: Cracked Orthophonic Reproducer
The brass one that I have been working with has a 40 pitch thread. The pot metal variety has a more course pitch. I can check it if anyone is interested. I'm wondering if there was more than 2 different pitches used, or was it simply one for brass and another for pot metal.De Soto Frank wrote:Apparently, one of the difficulties of replacing parts on original pot-metal Orthophonics is that VTM used several different thread pitches for the spanner-ring, according to Ron Sitko. ( And I have no reason to doubt him. )
So, buying a matched front & back would be the way to go...
I have a couple of "garbage" Orthos ( pot metal is beyond salvation ) that I am keeping for their diaphragms and needle-bars; someday I hope to get a couple repro bodies and do some transplants.