Orthophonic reproducer on HMV193 tone arm

[HMVDevotee]

Time for some expert advice. I recently put a fine-condition early (all brass) orthophonic reproducer on my HMV 193 to test for myself the claims that the Victor device sounded better than the HMV 5A or 5B.

To achieve a proper fit, the tone-arm end took one wrap of Teflon plumber's tape to close the tolerance between the OD of the arm and the ID of the brass fitting inside the reproducer. That accomplished, I used both thorn and bamboo needles for my thoroughly un-scientific test.

While playing with both needles, I noticed that the tracking path of the Orthophonic differs ever so slightly from the HMV devices, and the angle of incidence of the needle is steeper due to a different position of the pin-stop within the fitting.

Regarding record wear, certainly, the best alignment of a needle should include its pivoting axis to be parallel the record's groove. I suspect the pitch of the needle should make some difference as well. And I suspect it makes some difference with the frequency response of each reproducer (as does having pivots properly adjusted and lubricated.)

My questions are:

1. is the geometry of the Victor tone arm different from the HMV?
2. does this difference cause significant (noticeable) differences in the quality of sound reproduction?
3. considering wear to records, given the pliability of natural fibre needles, are these concerns only relevant to the use of steel needles?

(Happy to discuss my choice of three test records and my subjective findings on sound reproduction per reproducer should someone ask; My focus here is the mechanics of the instruments.)

Thanks in advance for your observations

Robert

[AZ*]

My questions are:

1. is the geometry of the Victor tone arm different from the HMV?
2. does this difference cause significant (noticeable) differences in the quality of sound reproduction?
3. considering wear to records, given the pliability of natural fibre needles, are these concerns only relevant to the use of steel needles?

Answers:

1. The Victor Orthophonic tonearms seem to have sharper curves than the HMV. While I have several Orthophonics, I only have an HMV 163 to compare. With respect to angle of incidence of needle to record, the Orthophonic instruction manuals state an angle of 68 degrees which is steeper than the 60 degrees stated in the manuals supplied with older conventional Victrolas with gooseneck tonearms and #2 soundboxes.

If you google Orthophonic tonearm, you can see what they look like.

2. I don't think so. Choice of needle, condition of soundbox, airtightness of horn and tonearm play a bigger role. The HMV re-entrants with metal horns generally outperform the Orthophonics with wood horns. The metal horn Orthophonics are a different matter. Despite the smaller size of the cabinet, the HMV 163 is louder and more brilliant than a typical Credenza.

3. This is very subjective. While some people believe that record wear is reduced by using fibre needles, others are convinced that using quality steel needles and changing them with every play will result in no record wear.

[Inigo]

HMV Devotee, I would suggest another possible variable you can use to adjust the tracking and performance. Maybe purists will cringe at my suggestion...
If the ortho soundbox neck fixing pin is like on the HMV soundboxes, it is a screw indeed. You can unscrew it and leave it apart. Then you are no more constrained by the pin engaging position, so you can adjust the angle of the soundbox, and you can vary it, say, from 55 to 70 degrees. This can help improving tracking, for you can make the needlepoint sit at different overall distance from the tonearm base. The vertical angle I believe (pardon) is not so important between these limits, and the variability allows you for a most important factor, which is to achieve the best possible tracking. You can also play with the projection of the needle, inserting it more or less into the chuck. Both plays surely allow for a better adjustment.
Using this trick on the HMV 194, I've achieved to play several sides with a bamboo needle (homemade) without repointing. That speaks for itself... little groove and needle wear, better sound, etc.
And using soft steel needles gives parallel results: no black record dust after playing, etc.

[OrthoFan]

I don't know how relevant this is, but initially, HMV supplied the "HMV No.5 sound box" with their Re-Entrant models -- http://forum.talkingmachine.info/viewto ... f=2&t=8585 -- which was supplanted very shortly by the 5a. 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, with the exception that the HMV 5 I owned was in perfect condition with no signs of swelling or cracks. Whether the Gramophone Co. changed the tonearm when the 5a took over, I don't know. A comparison of very early models and later ones would probably give a clue.

It will be interesting to find out what differences you detect between the Orthophonic sound box and the 5a/5b. I know that when I tried my circa 1927 pot metal Orthophonic sound box out on an HMV 102 portable I used to own, I heard a vast improvement in range and volume. The lower mid-range notes really came through. This, in spite of the fact that the gramophone's 5a sound box I compared it to had been expertly rebuilt, and the Orthophonic sound box was more or less as-found. The only objection I had was that certain components, such as the automatic brake mechanism, tended to vibrate in sympathy on some passages when the Orthophonic sound box was used, and I could hear them buzzing along with the music. This did not happen when the 5a sound box was used.

OrthoFan

[CarlosV]

I have a HMV 5 installed on my HMV202. Its sound is noticeably better than the 5a or 5b. I also tried a brass Victor orthophonic which is identical to the HMV5, and both have the same sound quality.

The angle to the needle of the orthophonic and the HMV 5 is indeed larger than that of the 5a/5b. I utilize only thorn needles, and I get good reproduction through the end of the side for most records in good condition.

[Inigo]

It could be the front of the soundbox, with its massive alloy body? The 5a/b have what seems a much lighter front ring and a light shell on top. But the body of the orthophonic always seems to me more massive.
The backplate is the same, or is it also thicker in the orthophonic?
A comparison of weights would be interesting.
On the other hand, the pivot arrangement and the back rubber isolator seen to work equally. Perhaps the ortho pivot arrangement is also heavier, adding mass to the difference.
One thing is clear from the physics side of it (easier when analysing the electrical analogy): increasing the mass of the soundbox conveys more sound power to the diaphragm. A light soundbox steals part of the power in body vibrations, which are cleared at the rubber connector, and at the tonearm base bearing. If the soundbox is more massive, the compliance of the rubber connector is not so important, for the soundbox mass is the first reaction point. Ideally, a fixed soundbox and tonearm would convey all the power directly to the diaphragm...
The second side of the mechanical problem: more mass on the soundbox is heavier on the record groove, but a judiciously balanced counterweight would solve this problem, leaving only the third side of the problem: the groove must carry the soundbox and tonearm in its slow trip towards the spindle. But this is so slow that produces only little wear on the grooves. A well balanced machine and a soft tonearm bearing solve this third question.

[Steve]

The 5 is far superior to either 5A or 5B. Sometimes it is true what you read!

[HMVDevotee]

Thanks for everyone's comments... helpful and informative.

AZ*: I measured my needle's pitch and found it to be approximately 68 degrees, consistent with your manuals statement. I'm fairly sure it was set at the factory since the rubber grommet that holds the brass collar in the back-plate had turned to stone! (more on that below.)

Inigo: Your suggestion regarding eliminating the locating pin from the back-plate got me thinking... So, with some old dental hygenist's picks in hand, I spent an hour carefully excavating the petrified rubber from the back-plate. On my orthophonic, the pin-stop was pressed and brazed into the brass collar; the (two) screws in the neck of the back-plate are set screws that clamp the outer rubber grommet, holding the brass collar and pin-stop in the proper position. With the new rubber grommet in place, I relaxed the position the assembly about two degrees and, as you suggested, effectively increased the distance from the tone arm base to the needle point, improving the overall tracking angle.... A great suggestion! Regarding geometry, the diameter of the 5B is larger than the orthophonic which leads me to believe that the tonearm length (without the reproducer) of the Victor machine must be longer to accommodate the smaller diameter orthophonic reproducer and achieve the best tracking. According to my wife's kitchen scale, the 5A weights 5.5 oz and the smaller, all-brass orthophonic weighs 5.75 oz. I agree with your observations about relative mass; a wiggling frame simply wastes energy.

OrthoFan & Steve: To the point of all of this... I concur that my orthophonic sounds better than my 5A's (tested two) and 5B's (tested three). It would be very interesting to plot a scope's recording of frequency response at different volumes (using a fibre needle to start, then and a loud-tone steel.) I found the HMV's to be a little "peaky," being pushed to the limit of distortion at certain loud passages with lots of simultaneous frequencies trying to be reproduced at once... passages of an organ music by Bach... the rich resonance of Nat King Cole's voice (again during loud passages). I use singers as test records because in the end, my standard for quality of sound is whether it is life-like and balanced. My final test is a 1944 recording of the tenor Jussi Bjorling singing Puccini's "Nessum Dorma" with full orchestration. The 5b (as mine is adjusted, I must add) simply cannot handle the overlay of frequencies at that volume. The orthophonic delivers an incredibly life-like sound (and scares the crap out of the cat. Our Lab sleeps through it.)

CarlosV: I was first hooked on the HMV re-entrant when I heard a 163 in person... the recording included a drummer playing brushes on a snare and a cymbal. The sound was so life-like, clear and detailed, as though the instrument was just behind the grill-cloth, and I began suffering from HMV Re-Entrant envy. A 202 with the HMV5 (or my brass orthophonic) would be the best! I've never heard a 202 in person, but I hope to one day. Finding one on this side of the Pond is highly unlikely. I was delighted to acquire a 163 and a 193. Might not live long enough to find a 202!


Again, thanks to all.

Robert

[CarlosV]

T Regarding geometry, the diameter of the 5B is larger than the orthophonic which leads me to believe that the tonearm length (without the reproducer) of the Victor machine must be longer to accommodate the smaller diameter orthophonic reproducer and achieve the best tracking.

Robert, I don't believe that the length of the arm was a factor when Victor designed the soundbox. The same orthophonic is used in portables with very short arms like the model 55 as well as in the Credenza, which has the longest arm among the orthophonic Victor models. The same lack of concern was adopted by HMV. the same 5A/5B soundbox being utilized in tneir portable 102 and in the large re-entrants (which also used originally the number 5). These companies were too big to be concerned with optimizing sound reproduction, their priority was set at maximizing profits, and that included standardization of hardware like soundboxes. That said, the HMV 202 has a superb sound, second only to the Expert and the EMG, with their large horns and a well-matched soundbox and plumbing.

[HMVDevotee]

Carlos,

Good points. I think many of us, myself included, interested in this antique technology are prone to seek some form of optimization, and some to the point of fanaticism! It's hard to imagine the manufacturers not being so dedicated, although I agree with you about their motives. Business is about cost/benefit. For collectors, it's the search for aesthetic perfection, a form of benign madness I suppose.

I've not heard an Expert or EMG in person, only on YouTube. Given the highly directional nature of acoustic horns, I wonder if the perceived quality of those instruments is due in part to the location of the center of the horn to the listener's ears. In my case, my 193 sits in a furnished room of good size with wood floors and a two-story cathedral ceiling. The reflective quality of the room, and the sheer volume of the 193, makes listening, anywhere, a pleasant experience. But, standing in front of it, or even ten feet away, the horn is pointed at my knees.

Determined to test my theory, I sat on the floor at about fifteen feet away with my head far closer to the center of the horn, and the difference was clearly noticeable. Higher frequencies are far more directional than lower, and that was the greatest audible difference. It certainly makes sense that folded horns suffer from impedance errors that are an inherent part of the design, "scientifically matched" or not. But it also makes sense that the Experts and EMG's owe part of their reputation to the simple physics of listening.

I guess it's a trade-off; I played a youtube video of a big EMG for my wife, suggesting that it might be my next acquisition. She said she'd rather have "...a stag's head in the dining room than that monstrosity, anywhere!" Ah, well...

R.