Fellow acoustic phonograph enthusiasts! Here I
essentially give away my invention to you which has too small of a market to
patent. I care that our recorded 78RPM musical heritage can be better preserved
while still enjoyed and played back on acoustic phonographs. Seriously, don't play your rare Blind Lemon Jefferson , Robert
This auction is for (1) a special spring and (2)
one replacement screw, washer, and nut for your reproducer back plate. After
you retrofit these items to your phonograph's tonearm and reproducer they will
offer you the opportunity to substantially reduce groove wear and improve
fidelity when playing 78RPM shellac disks. Once you achieve approximately
90-120 gm effective tracking force, those over-tracked, distorted records that
you may have been ready to throw in the trash can magically come back to their
former life AND you will detect much, much LESS record debris on the tip of
your needle after playback. You will feel much better about playing your
records. How is this possible?
We have seen counterweights on some EMGinn Expert
and EMG phonograph tonearms but makeshifting these onto other gramophone
tonearms designed for acoustic era reproducers (or especially those tonearms
made from cast aluminum) can place too much stress on them.
The solution: attach a counterspring to the pin or
screw of your main tonearm pivot at one end and then attach it to the
reproducer at the other end. The spring must be of just the right spring
constant (K) and length and near critically-damped under load. The attachment
string lengths can be adjusted for different reproducers to reduce the effective
tracking force by approximately 30-50%. The counterspring also assists the
needle in rising and retards it whilst falling as 'hill and dale' features (aka
warps) are encountered on lateral cut 78rpm records. As a result, it will
reduce needle wear and record carveout dramatically as seen in the Before and
After photographs in image nine. They show identical new premium nickel-plated
steel soft tone needles after a single play with and without the Counterspring
Kit retrofit.
How can fidelity also improve? As it turns out many
78 RPM shellac records we find at antique fairs, etc. may have been played with
steel needles used more than once or damaged. This chisels out a 'mesa
plateau' feature into the V shaped groove sidewall because the fattened tip of
the overly used needle never reaches the bottom of the groove. It also removes
some the recording from the sidewall above the level of damage. The evidence of
this damage from decades ago is often seen by observing the peculiar 'step
pyramid' pattern of wear on tips of new needles (used a single time) under a
20x magnifier. Then there are the all too common 78s that have been tracked
with an electric tonearm and a sapphire or diamond stylus at just a few grams
tracking force without any anti-skating correction. The very hard point
attached to the considerably lighter and more flexible arm (best for tracking
shallower, fine-pitched vinyl electronically at lower RPMs) skates up the outer
wall of the 78 groove V and all havoc breaks loose. In extreme cases of groove
damage the cross section of your new, single-use steel needle can end up
resembling a half or full profile of carpenter's paddle bit! A needle mounted
in a maladjusted needle bar causing the needle to tilt (camber) towards the
center of the record and forcing it to make the equivalent of a “reverse-banked
left turn” as it tracks the groove can also aggravate this. Finally, incorrect
storage of 78 RPM records (allowing them to abrade against each other without a
dividing sleeve) erodes the tops of groove walls and lessens groove depth
leading to similar symptoms. But by using a counterspring the point of the
needle remains very small throughout the entire record play so it can almost
completely access the undamaged groove modulations (ESPECIALLY during the last
2/3rds of the record!) below the carved out 'mesa plateau' in the groove V. Due
to the reduced drag, it requires your phonograph motor to produce slightly less
torque to maintain the 78RPM speed and it wears the record far less as you will
see from observing played needles with a 20X magnifier. Until now, using a much
harder material (Tungsten wire) in a filament needle was the only way to access
the bottom of the groove notch during the entire record play. However, these
types of needles are best used on shellac records in excellent condition and
are not recommended for worn records because of the potential for breakage of
the tip in tracking surface faults.
When using a counterspring the system compliance of
both mica and metal diaphragm reproducers is improved because there is less
force required from the spinning 78 RPM record grooves to move the needle, but
not so much less that the needle moves up the groove and mistracks. Because the
needle point remains much smaller over the duration of playback, damage to
larger diameter 12" 78 RPM records due to "tangent tracking
error" is also reduced. This is caused when the bi-facial wear pattern on
the needle tip (formed at the outset of playback) is no longer parallel to
grooves at the end of the 12'' record since acoustic phonograph tonearms use
radial pivots rather than linear translation. The reduction in record wear with
the Counterspring Kit will be the most dramatic with those electric era 78 RPM
records comprised of softer shellac formulations from the late 1930's and early
1940's. Soft or flexible vinyl 78 RPM records should never be tracked with an
acoustic phonograph.
Playback volume with my invention is not adversely
affected using my optimized spring values. They have been determined with my personally
rebuilt reproducers wherein I have used extraordinary care in replacing and
adjusting ball bearings, optimizing lubricant viscosity, aligning and centering
needle bars, adjusting needle-to-record attack angle so camber is between
neutral 0° to 3° towards the record edge and caster is ~30°, balancing springs
(in the case of mica diaphragms), re-fabricating tonearm flange sleeves from
Durometer 30-40 rubber, and using latex tubing or high density foam for
replacement diaphragm gaskets rather than the stiffer (higher Durometer) and
commonly-used silicon rubber tubing. A good ear is required for final tuning. I
am confident in my results.
I have empirically determined optimum tracking
force with this special spring for the Victrola #2, Meltrope III, Columbia #9,
Columbia #24, and HMV 5a and 5b, Alba (Paillard), and Brunswick Panatrope
reproducers. This Counterspring Kit will also work on Victor Exhibition and
Orthophonic reproducers (At $7 extra charge I will send you an ultra-thin clip
you will either insert between the Exhibition reproducer back plate and the
original screw as you would a washer or clip into the Orthophonic or Brunswick
Panatrope grille face). The screw provided fits most all the other listed
reproducers above. Specify if you own a Silvertone reproducer with a
removable back plate (a different screw is required). I have not yet had a
chance to optimize the Victor Orthophonic or Thorens Primaphonic. A Columbia
#15 can be used with a counterspring with excellent results but (depending on
whether US or UK made) a different, stiffer spring may be required. You can
purchase a scale and determine the optimum tracking force empirically yourself
for the reproducers I have not had a chance to characterize yet. NOTE: After
you win the auction I will share the exact spring extension length needed for
your reproducer. You will need to:
1. Purchase some hemp twine and cut two sections.
One section is attached to the far end of the spring and then to a washer which
will be added to the main tonearm pivot (see #2 below). The other section is
attached to the near end of the spring and the reproducer anchor point. This
second section of twine will require you make two clips (described in #3)
below. Using thick hemp twine ensures acoustic isolation of the tonearm from
the reproducer.
2. Fabricate a low friction washer for attaching
the section of twine tied to the far side of the spring to the main tonearm
pivot by cutting out a plastic laminated aluminum security cover for a beverage
container or vitamin bottle (now included) into a small, narrow rectangle and use a small hole
punch to make hole on each end. I show a Silvertone XVI console tonearm but any
Victor machine can be fitted simply by inserting the tonearm pin through one
hole of the makeshift washer. Most other acoustic phonographs can be
retrofitted using similar anchoring techniques.
3. Cut and bend paperclips to make a clip for each
side of the twine section on the reproducer side of the spring shown in the
photos. I used yellow paper clips + twine for the Meltrope III and red paper
clips + twine for the Victrola #2. The two clips allow the counterspring
to remain in rest position when not in use and to switch reproducers easily.
This is shown clearly in the last photo (twelve) with a Columbia #9 reproducer.
4. Remove the upper right reproducer back flange
screw after carefully cleaning the flat head groove first and using a
well-fitting screwdriver. You may wish to use penetrating oil in advance. Apply
very firm steady pressure while unthreading the original screw. Replace with my
screw, nut, and washer to create the counterspring anchor point.
The photos show: (1) Counterspring Kit including
one special spring, screw, nut, and washer (2) mass of Victrola #2 reproducer
160 gm (3) mass of Silvertone XVI tone arm after pivot 50 gm (4) combined
tracking force of Victrola #2 without Counterspring Kit 180 gm (5) combined
tracking force of Victrola #2 with Counterspring Kit 95 gm (6) mass of Meltrope
III reproducer 145 gm (7) combined tracking force of Meltrope III without
Counterspring Kit 205 gm (8) combined tracking force of Meltrope III with
Counterspring Kit 110 gm (9) new premium nickel plated steel soft tone
needles after a single play with (left) and without (right) Counterspring Kit
(10) Tungs-tone filament needle added for comparison showing that nickel plated
steel soft tone needles with Counterspring Kit after a single play compare
well..a fairly significant achievement considering the tungsten wire filament
of a Tungs-tone semi-permanent needle has a Mohs hardness scale rating of 7.5
versus the steel needle's hardness of 5 and its nickel overcoat with a hardness
of 4!! (11) Detail rear view of Counterspring Kit with Victrola 2 reproducer
(12) Detail front view of Counterspring Kit with Meltrope III reproducer
Note 1: The tonearm + reproducer mass measurements
fluctuate a bit based on the distance of the anchor point screw from the
tonearm pivot and from the reproducer center of gravity (different for
different reproducers) and give general and not exact mass indications which
cannot be directly compared between reproducers.
Note 2: Using cactus or Tungs-tone needles with the
Counterspring Kit should provide a further improvement. My own preference is to
use a material no harder than nickel plated steel to track a shellac disc.
Consider that though it is true a tungsten filament can never wear down to a
diameter exceeding the average groove width of a shellac 78 RPM disc, it is a
considerably harder material than steel and was an innovation spawned out of a
pursuit for convenience in avoiding needle changes and out of the WWI shortage
of steel for civilian uses..and not in the interests of record preservation.
Note 3: Ensure your main tonearm pivot is as
friction free as possible when using then Counterspring Kit. Although Dow
Corning High-Vacuum Grease is a great product for sealing tonearm seams and
stationary gaskets in reproducers, use a lighter lubricant for the bearing or
sleeve that pivots the tonearm across the record. The massive sleeve bearing on
Silvertone phonographs has great strength and is inherently self sealing
whereas the five 1/8" bearings, races, and notched sleeve in Victor
tonearms often require attention before adding lubrication to get a good
airtight fit combined with low friction.
Note 4: Best results will be obtained with the
Counterspring Kit after your 78 record grooves are as clean as possible. For a
"1st time" clean from the antique fair, I like cleaning 78 RPM
records on a flat, hard surface covered with plastic sheet. I use felt
purchased at a fabric store with a 45° nap to the fabric, lightly dampened with
distilled water, and wrapped over a section of foam pipe insulation. You must
let the records dry for 24hrs in a dry area. Even with regular rinsing, the
felt from the "1st time" clean will become contaminated with dirt and
shellac dust quickly and a new piece can be cut from your felt fabric supply to
replace it. Just before playing a 78 RPM record use a 2nd and separate DRY felt
fabric cleaner used only for 78s already "1st time" cleaned. You can
also find a Discwasher D3/D4 but use it only for 78 RPMs since it probably best
to keep the pulverized rock particles in the shellac 78s away from your vinyl
33s and 45s. With a deep kitchen sink, a commercial dishwashing spray rinse assembly or a Waterpik Water Flosser can also serve well for the 1st 'rough clean'. A full-disc white glue exfoliation can also work wonders. You must
not apply it too thickly, spreading it with an expired credit or muni card, and
catch it soon after drying to get a clean separation. Playback of badly worn 78
RPMs can be improved with the application of aqueous suspension wax products
such as Nikwax boot waterproofing since the 1-2 micron diameter wax droplets
are able to effectively coat & fill voids which interrupt the playing
surfaces.
Note 5: Never fabricate an adapter to track a left
mounting sound box such as a Brunswick Panatrope on the more common right side
of a tonearm since the needle tracking camber will be incorrect (reversed) and
this will cause excessive record wear and may increase distortion. Fabricate an
adapter to maintain the left-side-of-tonearm orientation of a left mount sound
box.
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GOOD LUCK BIDDING AND PRESERVING YOUR HERITAGE
78RPM RECORDINGS DURING PLAYBACK!!!!!!!!!!!!!!!!!!!!!!!!!!!!