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 Post subject: Re: Orthophonic reproducer on HMV193 tone arm
PostPosted: Tue Sep 17, 2019 3:00 pm 
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Victor II
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I've never had not listened to an ortho (5) soundbox in person. I have one golden 5A with new 5B diaphragm on my 194, one nickeled 5B on my 102, and a third spare 5A, which was assembled from surplus parts from renovation of the others. This last one I assembled last year, using an old tatty 5A surplus diaphragm (it was the original from the golden 5A st the 194) with creases, some tiny holes and all. I took it for learning, and did the whole restoration process as per experts instructions, disengaging the spider, softening and cleaning the diaphragm, sealing the holes, reattaching the spider, polishing the internals of the backplate and all. Finally I got a good 5A, tatty, but with an incredible sound, except for the treble which is a bit weak. I blame for this either the tired diaphragm or the vinyl glue I used to reattach the spider. This glue must be more stiff than common white vinyl glue... But I was obsessed with reversibility of operations.

The golden 5B sound very good on the 194, crisp and clear, and full of bass. It has been modified somehow, for I also overhauled it, and relaxed the pressure on the gaskets just to the airtight position and no more. I sealed the gap and secured the four screws with vinyl glue, so it works with slightly more compliance at the diaphragm edge, thus gaining an excellent bass. The original 5B diaphragm I've found to be less flexible than the 5A, because of stiffer edge configuration. This edge relaxing also helps increasing a bit the piston action. I also substituted the original rubber collar for a new one made for Meltrope soundboxes, just like those sold by chunnybh. This collar fits well on the soundbox, and can be directly pressed on the tonearm with the aid of a little water. It stays tight, but can be adjusted somehow (the length and angle) moving it out rotating.
It sounds marvelous with any record, even the most powerful ones (HMV orchestral and voice recordings of 1950, in the DB-21000s, André Kostelanetz US Columbias from late forties, etc).
In my channel I have several videos of this machine comparing a Meltrope III with the 5B. I never got that Meltrope to work properly on this machine, incurable lack of treble.

The nickeled (or chromed ?) 5B on the 102 sounds great, and when installed on the 194 sounds also good. It was also thoroughly overhauled and modified, but the diaphragm is like new.

How would sound a no.5 on this machine? Still better...? I'm intrigued, but the price is prohibited of the soundbox is well preserved. Years ago they were eBayed much cheaper, but now they range above the $100 mark in good shape!
Inigo


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 Post subject: Re: Orthophonic reproducer on HMV193 tone arm
PostPosted: Tue Sep 17, 2019 6:00 pm 
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Victor Jr
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Inigo,

You underscore an important point; my remarks are simply coincidental. The best test would be to compare two reproducers gone over by a technician. The two that I used in my comparison were the best (and in the case of the orthophonic, the only) one I had on hand. I will say, of the three 5b's I have, one, with the perfectly pliable and original rubber fitting was clearly the best of all the lot of 5a and 5b's that I have. Frankly, for 40's Big Band, I prefer it to the orthophonic.

I have never seen an HMV 5. Were they made entirely of brass like the early orthophonics, or were they the pot metal, nickle plated steel? And are they the same dimensions? I find it curious that HMV would shift to a larger diameter reproducer with the 5a and b. Perhaps they were looking different frequency response.

Robert


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 Post subject: Re: Orthophonic reproducer on HMV193 tone arm
PostPosted: Tue Sep 17, 2019 7:30 pm 
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Victor IV
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HMVDevotee wrote:
I have never seen an HMV 5. Were they made entirely of brass like the early orthophonics, or were they the pot metal.
Robert


As I noted in my post on the previous page, I used to have an HMV 5, and can verify that it was absolutely identical to the pot-metal Victor Orthophonic sound box produced at the time. I believe that all of the HMV 5 sound boxes were pot metal considering their late introduction date in the UK market--1927(?). The brass Orthophonic sound boxes were only produced for a few months, early in the initial line of Orthophonic Victrolas, starting in 1925.

One of the explanations for the HMV 5 sound box's quick demise was that the pot metal used in the casting was of inferior quality, and they began cracking/crumbling almost immediately. Nonetheless, the one I had, as I noted, was in excellent condition with no signs of deterioration. Wish I still had it!

OrthoFan


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 Post subject: Re: Orthophonic reproducer on HMV193 tone arm
PostPosted: Wed Sep 18, 2019 3:08 am 
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Victor II
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What is a surprise is to know that the 5 was smaller than the 5a/b. The orthophonic diaphragm seems equal to the 5A's, with the diagonal edge creases. Is it actually of smaller diameter?
Then the design of the soundbox is specifically different, although based on the same principles. We have a smaller diameter diaphragm and a slightly different mass (1/22 greater). The needlebars are exactly the same dimension? There were could have another small variation. All in all, it could be the same basic soundbox, but tuned to a slightly different specification. This solely, although the differences are small, justifies a different sound.
Colleagues notice the difference in sound.
In my little experience with my 'tuned' 5As and 5Bs, my variations are but very small, but one can hear the difference in sound, most noticeable in the slight but good increase in the bass region, and in a different quality of sound. My 5A when restored to the original specs and tested in the 194, have these impressions:
1) With the original 5A diaphragm the sound was good, but there bass resulted a bit exaggerated due to a certain lack of high treble; I blamed this to a more flexible diaphragm, maybe somewhat 'tired'.
2) If the 5B diaphragm was installed instead, it gave a good sound, more crispy and with better treble, seeming to loss a certain amount of bass, although this could be a sensation provoked by the noticeable presence of treble; but the overall sound resulted somewhat 'compressed', with a clear sensation that loud passages were exaggeratedly 'pumped out' by the soundbox.
After the treatment and slight modifications of last year, explained above, the 5A with the 5B diaphragm gives a much better sound, with bass and treble, and no 'compression' at all, sounding very well both soft passages and in the loudest ones. The sound is full, clear and 'opened', in all records I've played, both good acoustics and electrics. I feel I've had the luck to find the right adjustment point for that particular soundbox in that particular horn. To listen to a Bluebird by Fats Waller is a treat, as it is to play a late extended range HMV orchestral/operatic one, like late version of Nessun dorma by Gigli, or any song by Kirsten Flagstad, for instance. US Decca blue label records, even with the inferior shellac, sound great, crispy and full-range.
So small differences in the adjusting point on these soundboxes can make a great difference. I fully believe your observations about the better sound of the no.5/orthophonic sound...
The best sound in my case is obtained when using a good thick bamboo needle, or a soft tone steel needle, although this gives more treble. I prefer good bamboos.
Inigo


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 Post subject: Re: Orthophonic reproducer on HMV193 tone arm
PostPosted: Wed Sep 18, 2019 8:29 am 
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Victor IV
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I have several No. 5's along with 5A's and B's of varying conditions. I have to say the 5 is superior to all of them based on my own subjective experience. The bass is far better.


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 Post subject: Re: Orthophonic reproducer on HMV193 tone arm
PostPosted: Wed Sep 18, 2019 12:07 pm 
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Victor Jr
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My apologies to Inigo (in particular)....

My remarks about the 5A and 5B being a larger diameter than that the orthophonic (and I assume the HMV5) were only partially true... the difference that was apparent, and probably of no consequence, is in the construction. The back plate of the 5A and 5B, is simply larger in diameter (65mm) than the brass housing of the orthophonic (62mm) into which its brass back plate is fitted with a threaded retaining ring. Eyeballing with a caliper yields 36mm from the center of the unit to the end of the chuck, and 46mm from the center to the end of an inserted needle. Clearly, the internal measurements are the critical ones and those I've not taken having not broken-down either reproducer.

And this clarifies my confusion about different tracking angles... the difference in total length of the tone arm, as measured from it's pivot point at the horn to the end of the needle when measuring both units, was due to the steeper pitch of the needle as originally set up on my orthophonic. Thinking that I needed to replicate the tracking position of the 5A, I had relaxed the pitch on the orthophonic about 2 degrees when I reassembled the rubber/brass fitting.


Other than producing less surface noise with the reduced pitch of the needle, I don't hear any difference in sound characteristics. There must be some, but to my old ears, but I can't say that it is noticeable.

Sorry for my sloppy initial observation.

R.


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 Post subject: Re: Orthophonic reproducer on HMV193 tone arm
PostPosted: Wed Sep 18, 2019 3:59 pm 
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Victor III
Joined: Sun Mar 15, 2009 6:18 am
Posts: 971
Inigo wrote:
Then the design of the soundbox is specifically different, although based on the same principles. We have a smaller diameter diaphragm and a slightly different mass (1/22 greater). The needlebars are exactly the same dimension? There were could have another small variation. All in all, it could be the same basic soundbox, but tuned to a slightly different specification. This solely, although the differences are small, justifies a different sound.


Inigo, the nr 5/orthophonic design is significantly different from the 5A/5B. The diaphragm, the connection to the needle bar, the needle bar itself, the bearing system and key dimensions differ in both. In other words, there is little in common in both designs. The number 5/orthophonic is a new design from scratch, while the 5A/B is an adaptation of the HMV 4, which is designed with a mica diaphragm, to a aluminum one, inheriting the same needle bar bearing, and changed to a non compliant gasket and a new body.

I have a number of 5A/B soundboxes, and find their sound very variable in terms of quality. As they do not have rubber or wearable parts other than the gasket that connects to the arm, I believe that such variability in quality may be due to pot metal action changing dimensions over time. The most common evidence I have found on some of them is the crack of the front plate on its side, caused by swelling of the back plate.


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 Post subject: Re: Orthophonic reproducer on HMV193 tone arm
PostPosted: Thu Sep 19, 2019 9:55 pm 
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Victor IV
Joined: Sat Jul 09, 2016 7:12 pm
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CarlosV wrote:
Inigo, the nr 5/orthophonic design is significantly different from the 5A/5B. The diaphragm, the connection to the needle bar, the needle bar itself, the bearing system and key dimensions differ in both. In other words, there is little in common in both designs. The number 5/orthophonic is a new design from scratch, while the 5A/B is an adaptation of the HMV 4, which is designed with a mica diaphragm, to a aluminum one, inheriting the same needle bar bearing, and changed to a non compliant gasket and a new body.

I have a number of 5A/B soundboxes, and find their sound very variable in terms of quality. As they do not have rubber or wearable parts other than the gasket that connects to the arm, I believe that such variability in quality may be due to pot metal action changing dimensions over time. The most common evidence I have found on some of them is the crack of the front plate on its side, caused by swelling of the back plate.



Carlos:

Many thanks for comprehensively citing the differences between the Orthophonic/HMV 5 and HMV 5a&b sound boxes. There's one other difference I've been wondering about.

Decades ago, I was in regular correspondence with a collector-historian whose main interest was in Orthophonic Victrolas. In fact, he wrote a number of articles about various models for the long-defunct "New Amberola Graphic," some of which may be available online on the Internet Archive site -- https://archive.org/search.php?query=%2 ... Graphic%22

The collector told me that the main reason for the sonic difference was that the Gramophone Co. modified the impedance of the HMV 5a/b sound box by positioning the diaphragm closer to the back plate. (I don't pretend to understand "The Theory of Matched Impedance" though I did read through it several times.) This, he said, gave the the sound box (if I remember correctly) more of a neutral or flat frequency type response to all notes, which matched the acoustic properties of the Re-Entrant model's all metal tone chamber. I do remember that he specifically stated, "the Orthophonic Victrola was not designed to have a metal horn."

As I noted in my post on the first page of this thread, when I tried an Orthophonic sound box on my HMV 102 portable, the overall volume, range, etc., was greatly enhanced. The only issue I detected was that the auto brake lever buzzed on certain notes, as if the horn were being over-driven. I'm wondering if there were similar issues when the sound box was used on the early Re-Entrant models, especially in light of what David Cooper writes about the development of the HMV 102 portable:

"By February 1928, tests proved that an adjustment problem in the No. 5 sound box was causing a 'buzz' that was not easy to eliminate..." Page 55; "The Perfect Portable".

OrthoFan


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 Post subject: Re: Orthophonic reproducer on HMV193 tone arm
PostPosted: Fri Sep 20, 2019 7:34 am 
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Victor III
Joined: Sun Mar 15, 2009 6:18 am
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OrthoFan wrote:
CarlosV wrote:
I do remember that he specifically stated, "the Orthophonic Victrola was not designed to have a metal horn."

OrthoFan


OrthoFan, the Victor VV-8-35, the one that looks like a small bookshelf, has a metal horn AND the soundbox is the orthophonic. I have one and it sounds very well, actually with a better reproduction than the Credenza. The material of the horn is only of secondary importance in its acoustic performance, provided that its not highly absorbant and that it remains stable. Its shape and dimensions are the key factors to determine its frequency response.

Concerning the portables, it is possible that there was some incompatibility between soundbox and arm when the 102 was being designed, although I believe the number 5 was already discontinued when the 102 was placed in the market, and the first ones were sold with a cheap soundbox, with the same design originally sold with Victor portables like the VV2-35, that looks like a sardine can and cannot be opened for servicing. I have some samples of this soundbox, both US and English-made, and could never get a decent sound out of them - maybe this is the orthophonic the book refers, as it was replaced by the 5A after the initial batch of 102s was sold.


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 Post subject: Re: Orthophonic reproducer on HMV193 tone arm
PostPosted: Fri Sep 20, 2019 9:57 am 
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Victor II
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HMV dev, dont apologize at all! This is a tech discussion, and I'm only expressing my humble opinions.. don't forget I've never listened live to a no5/ortho soundbox, not have seen it actually in my hands! My POOR experience of only from 3 5a/b i own and no more! You are the experts! Sorry if my long posts and technical enquiries give the false impression I'm a Doctor on this matter...
I'm only too enthusiastic explaining my intuitions and my experiments with the 5a, which it's true is that in my particular example I've arrived to a most satisfactory sound. But if I ever own ano.5/ortho, maybe I'd have to retract publicly! :D
Inigo


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