Hi Greg,
I read with interest your two recent emails. While I agree that there
probably isn't much of a market for a better design orthophonic reproducer
when you consider the cost to make such a complicated item on a very small
scale. However I think that tungsten needles is a different story. I think
just about every phono collector would like a source for tungsten needles;
when you see what they go for on eBay. I'm sure quite a few of us have old
Victor tins for tungsten needles that we would like to refill. I would
think that someone with your mechanical talents could come up with the
tooling to automate the production process and turn them out in quantity
economically. Therefore I urge you to consider manufacturing them and
making them available to the phono enthusiast community.
RMV
----- Original Message -----
From: "Greg Bogantz" <gbogantz1 at charter.net>
To: "Antique Phonograph List" <phono-l at oldcrank.org>
Sent: Friday, February 08, 2008 10:10 PM
Subject: Re: [Phono-L] Victor versus Columbia big guns
> Hi Robert,
>
> To answer your general curiosity, yes, I
> have tried many of the things you suggest. I have designed and made a
> complete "New Orthophonic" (with apologies to RCA who couldn't care less
> at this point since they're owned by the Chinese) reproducer to fit Victor
> ortho tonearms out of lathe-turned aluminum - none of the parts are
> recycled
> from old designs. The aluminum model weighs about half of the potmetal
> design. I don't want to divulge too much more of the design in case I
> eventually want to make and market it. But it really isn't ready for that
> yet. Even so, I don't know how much market there would be for a toy like
> this. Most phono collectors don't obsess about the audio performance of
> their acoustic machines like you and I do. Their attitude is that
> anything
> that isn't an original 100 year old design constitutes a "frankenphone"
> and
> they don't want anything to do with it. So I'm not encouraged that there
> are more than a dozen of us with this interest.
>
> As an adjunct to this design, I also have been making for some time now
> my own tungsten needles. This started out because I needed durable
> needles
> to use in my oldest record changers that are designed for steel needles.
> Steel needles are no good for these changers because they wear out
> completely after two record sides are played. So, what's the point of
> having a record changer if you have to change the needle every two record
> sides? Victor recommended their Tungstones for this purpose, and indeed,
> they were the best choice for this application at the time. But I didn't
> want to use up expensive, original, antique Tungstones so I designed my
> own.
> What I found out was that the original tungsten wire used by Victor is
> .007
> inch (7 mils) in diameter. This is really too big for the typical groove
> which is around 5 to 5.5 mils in width. But they used it because anything
> smaller is too delicate and bends too easily. Also, the heavy tracking
> force of the early reproducers, both the acoustic and the early horseshoe
> magnet electric types was sufficient to mash the fat wire into the record
> groove and keep it working even though it was wearing "shoulders" on the
> sides of the too-big wire. So when I tried to use these 7 mil tungstens
> in
> my new reproducer which tracked at half the force of the Victor (about 80
> grams versus 135 grams), the wire didn't wear down properly on the
> shoulders
> and stay in contact with the groove walls. This caused audible
> mistracking.
> I have since gone to 6 mil wire which works pretty well. I would rather
> use
> 5 mil wire, but I've tried it and it's just too fragile and bends too
> easily. So this is yet another problem that requires some compromise.
>
> To address your suggestions about using large diaphragms: you are
> faced
> with a tradeoff between diaphragm compliance, resonance, and application
> requirements. If you want to try a "Lumiere" type of very large
> diaphragm,
> or direct radiator cone really, then you can't effectively horn load it,
> and
> you probably don't want to anyway. You can simply let such a large
> vibrating surface radiate directly into the surrounding acoustic space as
> is
> done with the Lumiere and Pathe Actuelle designs. Such a design can sound
> pretty good in the midrange of audio, but it is inherently limited in how
> much bass it can reproduce - there just isn't efficient coupling with the
> air mass at very long wavelengths of audio (bass frequencies) to get good
> bass response. To load a large diaphragm into a horn would require a
> large
> horn throat to accommodate it. Which would require a VERY large horn to
> work into to keep the compression horn acoustic principle working
> properly.
> Improper mismatches in sizes here result in vastly reduced efficiency.
>
> Long story short(er), the approximate sizes of the diaphragm,
> reproducer
> throat, and horn length and flare are just about optimum as realized in
> the
> Victor designs for the application of playing 78rpm records with 5 mil
> wide
> grooves. Bigger systems would require bigger records and bigger grooves
> to
> keep the mechanical couplings and impedance transformations working
> correctly. Loading a typical 78rpm groove with a correctly-designed large
> diaphragm compression horn system would simply cause too much mechanical
> loading on the needle. This would result in very low compliance at the
> needle tip which would result in severe mistracking. Furthermore, the
> extreme mass of the entire system would be difficult to track with a
> pivoted
> tonearm under groove power, as you suggest. But lateral-cut records do
> not
> lend themselves to feedscrew-type tonearm assist systems because most
> records are not cut at a constant groove pitch which cylinders are. Then
> there's the problem of record eccentricity that must also be accommodated.
> You could address these issues with a sophisticated servo-controlled
> tracking system. But it all adds up to swatting a fly with a sledge
> hammer.
> So it turns out that the approximate sizing of the playback elements as
> seen
> in the Victor (and others) designs is probably about optimal for real
> world
> use. But that doesn't mean that you can't put a considerably larger horn
> on
> a Victor-sized system. To do so would extend the bass reproduction
> frequencies down lower. Victor themselves did that in their theater-sized
> horn designs. But the efficiency tends to degrade with increasing horn
> size, so even the biggest theatrical Victors used electrical horn drivers
> and electronic amplifiers.
>
> You mention the excesses of the Archeophone design: True, this is
> pretty much overkill, too. But there really aren't any modern cylinder
> player designs that offer highly accurate record speed and vanishingly low
> flutter, so these are two design criteria that are purposefully addressed
> in
> the Archeophone. However, the basic business of turning a disc record and
> holding a reproducing means in the groove have been developed for years
> past
> the acoustic technology as embodied in all modern disc record players.
> All
> that really needs to be done if you want to extract the most from a disc
> record is to use a modern hifi pickup equipped with the proper size and
> shape stylus. Done deal. It doesn't need re-inventing.
>
> But I DO understand that you are trying to "squeeze the turnip" and see
> how much blood can be extracted from pure acoustic playback technology.
> But
> I CAN tell you that it is NOT possible to make the "perfect" acoustic
> reproducer - you can't get fully wideband frequency response AND
> low tracking force AND good efficiency (loudness) from an acoustic design.
> It's just not in the physics. Unlike the situation with modern hifi
> pickups, the physical requirements of an acoustic reproducer are vastly
> different. The modern record player does not require anything more of the
> record than to merely "instruct" the player on how to direct its
> electrical
> energy to the loudspeaker. This requires an infinitesimal amount of power
> from the groove. By contrast, an acoustic player extracts ALL its sound
> power from the record groove (assuming you aren't using a mechanical
> amplifier such as the Higham friction amplifier or compressed air schemes
> such as on the Auxetophone). This makes all the difference in the world.
> Acoustic playback requires that all the audio power must be extracted by
> making the record groove do the actual work. The more work the groove
> must
> do, the more wear is likely to be exhibited as the needle scrubs along the
> groove walls. You quickly get to the point where you can't get any more
> blood out of it. The Victor design is close to the optimum, in my
> estimation. I've been able to improve upon it, but I don't expect that
> too
> much more can be had from what I'm getting now. But I'd love to be proved
> wrong, if someone wants to have a go at it.
>
> Greg Bogantz
>
>
>
> ----- Original Message -----
> From: "Robert Wright" <esroberto at hotmail.com>
> To: "Antique Phonograph List" <phono-l at oldcrank.org>
> Sent: Tuesday, February 05, 2008 10:16 PM
> Subject: Re: [Phono-L] Victor versus Columbia big guns
>
>
>> Wow, thanks for all the great information, Greg, and thanks for taking
>> the time to type/copy&paste it all! I'm wondering additionally about
>> using space-age materials and creating something using a Victor horn
>> that's beyond comparison with any antique products of any kind. I'd like
>> to see, for starters, what a larger diaphragm suspended by a rubber
>> surround in a milled aluminum soundbox with a titanium stylus bar and
>> razor blade pivot point would do mounted to a Credenza tonearm. With a
>> larger diaphragm and soundbox, some counterbalancing (a la Ultona) might
>> be necessary, but with aluminum instead of brass, maybe not.
>>
>> That's just for starters. I'd also be interested in creating an even
>> larger soundbox, say 10" or so, with similar materials (think modern HMV
>> Lumiere), mounted rigidly (laterally speaking) to a large, non-folded
>> exponential horn (a la Nimbus Records'), with a modern direct drive
>> turntable mounted to a feedscrew stand so that the disc moves laterally
>> under the stylus (think Wizard or other moving-mandrel cylinder phonos).
>> Maybe a titanium diaphragm to keep moving mass to a minimum... Granted,
>> this would be truckloads of cash to build, but I figure if they can build
>> the Archeophone...
>>
>> continuing to dream,
>> Robert
>>
>>
>>
>> ----- Original Message -----
>> From: "Greg Bogantz" <gbogantz1 at charter.net>
>> To: "Antique Phonograph List" <phono-l at oldcrank.org>
>> Sent: Tuesday, February 05, 2008 8:34 PM
>> Subject: Re: [Phono-L] Victor versus Columbia big guns
>>
>>
>>> Well, Robert, I think I agree with you that the Credenza is the
>>> standard of excellence in American acoustic reproduction. I have an
>>> early 2-door Credenza as well as a Victor 10-50, 9-40, and 10-35 as well
>>> as a Columbia 810 which has the biggest horn that Columbia put in their
>>> Viva-Tonals. I don't hear too much difference among the big Victors,
>>> but each has subtle differences from one to another. All are GREAT
>>> machines, and any owner should be proud and pleased to listen to them.
>>> The reason that I put that caveat about American acoustic reproduction
>>> is that I haven't had the pleasure of hearing any of the really good
>>> English machines such as the biggest re-entrant HMVs or the biggest
>>> EMGs. Maybe one of them can claim the prize as best acoustic machine,
>>> but I just can't say. I must opine, however, that I can't imagine the
>>> EMGs having as good bass as the biggest exponential horn machines simply
>>> because EMG didn't use as big a horn!
>>>
>>> Now, with all due respect to Anthony Sinclair, and I truly do mean
>>> that I respect and applaud his efforts to document the performance of
>>> orthophonic and other machines in his writings in ITG, I must beg to
>>> disagree with some of his opinions. By the way, we've recently had some
>>> of these very same discussions on the Old Time Victrola Music Message
>>> Board (OTVMMB), but I'll repeat here what I've written there for those
>>> of you who aren't also members there. I encourage you folks to go there
>>> and see what else has been said recently about this topic. I don't
>>> presently have the proper instrumentation to back up my claims, but I've
>>> listened extensively to the big horn Victors and compared them to the
>>> Columbia. I have made an adapter that allows me to listen to the
>>> Columbia #15 Viva-Tonal reproducer played thru the Victors, and also
>>> allows me to use the Victor orthophonic reproducer on the Columbia. I
>>> was particularly interested in whether the horns or the reproducers were
>>> the limiting factor in acoustic reproduction on these machines.
>>>
>>> In my opinion, the Columbia horn is not as good as the Victor. The
>>> Columbia horn is not as accurately tapered because it is constructed in
>>> a piecewise-linear-curved sectional fashion rather than having a
>>> smoother, more uniform and proper exponentially increasing cross section
>>> which is required of the exponential design. There should be NO
>>> cross-sections in a proper exponential horn which are linear taper.
>>> This, in particular, causes the treble to be noticeably weaker than the
>>> Victor. But the bass is also less extended as well. And, overall, the
>>> efficiency isn't as good as the Victor (it doesn't play as loudly) - all
>>> these attributes are symptomatic of an incorrect horn taper. At first
>>> blush, the Columbia strikes the casual listener as having more bass, but
>>> this is due to it's having substantially less treble than the Victor.
>>>
>>> Another finding indicates that the big Victor horns are better than
>>> people realize because the Victor reproducer isn't as good as the big
>>> horns. More on this later. The Victor ortho reproducer has several
>>> compromises included in its design to make it more robust and more
>>> user-friendly that, unfortunately, detract from the best acoustical
>>> performance that could have been had. The bass could be a little better
>>> if the compliance was higher, and the treble could be a little better if
>>> the moving mass was lower. That said, the Columbia #15 is no match for
>>> the Victor ortho. It has a more massive diaphragm which further
>>> degrades the treble, and the compliance is even lower (stiffer) which
>>> further degrades the bass, compared with the Victor. The Columbia has
>>> the very big advantage that it is all made of brass and is easily
>>> rebuilt, but it still can't match the performance of a Victor ortho in
>>> good condition.
>>>
>>> The reason that I know the Victor horn is capable of more than most
>>> people realize is that I have designed a better reproducer than the
>>> Victor. My design has a MUCH lower moving mass and quite a lot higher
>>> compliance than any other reproducer that was sold to the public.
>>> Incidentally, I was particularly interested to see if this could have
>>> been done "back in the day" by trying to use only materials that would
>>> have been readily available in 1927 or so - no modern space-age
>>> materials. And I discovered that it could have been done - the
>>> materials are aluminum, leather, and paper with a few screws and glue
>>> thrown in to hold it together. I guess the reason why a design like
>>> this wasn't marketed is related to the delicacy of a proper design. The
>>> low moving mass and high compliance both make the reproducer delicate
>>> and difficult to perform needle changes. I'm sure my design would never
>>> have been suitable for mass consumption, but I like to use it because it
>>> makes the Victor horn really shine! Reproduction on this system sounds
>>> like that of a large table radio or small radio console - I estimate
>>> that it has about an extra octave of useful output, some above and some
>>> below the range of the Victor ortho. The bass is not window-rattling,
>>> but it's uncommonly good and the sound is well-balanced and wide-range
>>> without peakiness, and most listeners can't believe that they're hearing
>>> acoustic reproduction. So, yes, the big Victor horns are the best
>>> acoustic horns that I know of and are damn fine at that.
>>>
>>> Greg Bogantz
>>
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