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ה - GRASSHOPPER III היא סידרת ראשי פטיפון Moving Coil ברמות הגבוהות ביותר. סידרה זו נחשבת לאחת מהטובות בעולם האודיו והמוערכות ביותר על ידי כמעט כל המגזינים בעולם. הסדרה כוללת 4 דגמים יחודיים אשר ניבדלים בהגברות OUTPUT שונות וב חיווט שונה. עם זאת , המאסטר בתחום והאדם שבונה אותם בעבודת יד A . J . Van Den Hul מתאים אישית ללקוחות את ההגברה לאחר שהוא לומד את הפטיפון וה קדם פטיפון { Phono Stage }שלהם במידה ויש הצורך.
להלן דגמי סדרת ה GRASSHOPPER III:
1.The GRASSHOPPER III SLA עם Output של 0.6 mV/channel וחיוט Silver coils .
2.The GRASSHOPPER III GLA עם Output של0.6 mV/channel וחיוט Gold coils .
3.The GRASSHOPPER III CHA עם Output של 2.25 mV/channel וחיוט Copper coils .
4.The GRASSHOPPER IV GLA עם Output של 0.65 mV/channel וחיוט Gold coils .
-שידרוג GRASSHOPPER ישן : מאז 1978 ועד היום הסידרה מיוצרת ומשודרגת וללקוחות שיש להם ראש ישן יש בחברה מלאי של חלקים של הדגמים הישנים לחידושם ובמקרים של בקשת הלקוח יש אפשרות לשידרטגם כמעט עד לרמה הנוכחית ובמקרה כזה יחסוך הלקוח לא מעט כסף בשידרוג במקום לקנות ראש חדש.
להלן כתבות ומאמרים על סידרה זו ממיטב מגזיני העולם :
1. המגזין היוקרתי The Absolute Sound
http://www.vandenhul.com/artpap/grh-iv3.htm
2. פרס ה GOLDEN EAR AWARD
http://www.vandenhul.com/artpap/grh-iv-awd.htm
3.המגזין הגרמני German magazine Image HiFi
http://www.vandenhul.com/artpap/gh4image.htm
4. המגזין Stereophile
http://www.vandenhul.com/artpap/grh-iv.htm
5.המגזין Hi-Fi World
http://www.vandenhul.com/artpap/grh-iv2.htm
-הפילוסופיה שמאחורי הסידרה עיי A.J.Van Den Hul
The design philosophy of The
GRASSHOPPER IV GLA.
By: A.J. van den Hul, Cartridge Designer.
Is it still possible to make big improvements in the construction of phono-cartridges?
The GRASSHOPPER IV, being a typical example of the application of innovative technology, proves that this indeed is still possible...
The technical aspects:
1: The special van den Hul stylus:
All GRASSHOPPERS do use a special selected version of the VDH type 1 stylus, called the VDH 1S.
This stylus has the best tip-shape with the finest polish. So replay noise is as low as technically can be achieved. The regular stand-time of the 1S stylus averages at around 3000 hours of playing.
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2: A reduced cantilever length:
The standard cantilever is made of 300 micron boron.
Using new technology, the total length is reduced by 25%, working very well for improved dynamics and a strong reduction in harshness at high frequencies.
Also the units become more robust due to the shorter cantilever; Resistance against accidental mechanical overstress is increased.
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3: The golden coil wire:
For the two coils we apply a 24 carat enamel-insulated matched crystal goldwire.
Using this very pure gold, many electrons are available for conduction and few for binding the atoms together.
Gold is chemically very inert, so there is no degradation.
Since the total - extremely low-level - audio current runs through the 20 micron goldwire, its dynamic conductive properties are very important.
A stable conductor therefore speaks for itself.
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4: Crosstalk:
The crosstalk levels are reduced by winding the left channel coil also in the right channel and vice versa.
Especially this constructional aspect accounts dramatically to its open soundstaging.
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5: Special quality connecting leads:
The four colour-coded connecting leads, attaching the coils to the connecting pins, are each made of seven separate Nylon-insulated pure matched crystal silver strands. (This wire is a special product of ours, available as the MCS - 150 M).
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6: Reduced magnetic modulation noise:
The armature is made of practically Weisz-domain free iron. Ferro-magnetic materials don’t change their magnetic polarisation per atom, but rather groupwise (domains).
When the size of these domains is decreased, each magnetic field change is responded to by the material’s polarisation in a higher number of smaller steps; This expresses itself in a reduced modulation noise level. The modulator’s square armature shape is also very helpful here.
The result is a signal waveform practically free of steps. The much reduced noise floor results into an enhanced sense of resolution and spaciousness.
This total noise floor is the sum of modulation noise and surface noise. With the strongly reduced modulation noise, only the record surface noise is left.
The extremely low level groove information from now on is no longer masked, and this means that the senses of spaciousness and resolution improve a lot.
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7: Special resonance-controlled body material:
The GRASSHOPPER IV body is made of transparent polycarbonate: a light material.
The total cartridge weight is reduced to 8.2 gram.
The polycarbonate body is threaded for easy installation: two stainless steel Allen-head bolts are packed together with each cartridge.
The polycarbonate combined with the special shape of the body, dramatically reduces the transmission of the partial vibrations of the motor into the tone arm.
As a result, the coloration by tuned and sensitive tone-arms is dramatically reduced.
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8: Open construction and resonances:
The GRASSHOPPER cartridge has a very open construction.
The big advantage is that there are no resonating body panels anymore. Each panel has its own set of resonance frequencies with their own Q-factors. Al this unwanted energy couples to the arm which again has its own resonance modes. Since energy couples both ways, this again builds up extra coloration energy for the cartridge.
Therefore, to prevent any extra mechanical energy going around, The GRASSHOPPER IV is kept very open. The disadvantage is that the cartridge must be handled with some extra care.
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9: Special armature shape:
The shape of the armature is square. This improves the output level with 25% compared to e.g. a cross-shaped armature. Automatically the gain of the pre-pre-amplifier can be reduced by 25%. This means that the signal to noise ratio will be improved by 25% (about 2dB) whilst maintaining the same preamp output level.
The more iron involved, the higher the output per turn; The resolution of very low signal levels is improved because the higher output level allows less masking of the groove information by the preamp noise.
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10: Improved crosstalk-level stability:
The total contact area between the square armature and the dampers is enlarged due to its shape. This results into a better grip from the rubber on the modulator. Channel unbalance by the armature’s rotation over time now is strongly reduced. The crosstalk levels therefore will stay closer to their adjusted position.
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11: Much attention is paid to the suspension rubbers:
The suspension rubbers (two are applied) are especially selected for the best performance in soundstaging, tracking and durability. The outer damper is particularly responsible for the very high sonic resolution.
The lower sensitivity to variations in tone-arm mass is accomplished by the special inner damper with its enlarged compensation volume.
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12: Special quality inner support wire:
The inner support wire (positioning the armature in the gap), is selected on very low metal-fatigue properties. The mechanical stability and durability therefore are strongly improved;
You will never find a loose coil “hanging” around. Even after a heavy accident this very rarely occurs.
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13: Special pole construction reduces crosstalk further:
The rear and front-pole are 2mm. thick. This size is an exception in the cartridge world. The increased thickness of the pole material reduces the magnetic crosstalk between the two channels; the magnetic interaction between the two signals is further reduced.
On special request, even a 3mm. thick front-pole can be mounted. (This involving some extra cost).
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14: Dynamic crosstalk aspects:
The application of two special silver eddy-current dampers around the magnet and its rear pole, further reduces the dynamic signal crosstalk.
Explanation: The common-mode component in the two channels is always the harsh signal that audibly seems to emanate from an area centred between the two loudspeakers. Due to the innovations mentioned at 4, 6, 7, 12, 13 and here, this unpleasant signal component is dramatically reduced. This common-mode component is mainly composed of higher harmonics originating from non-linearities in the magnetic modulation and unstable movements of tip, cantilever, armature, suspension-rubbers and support-wire.
In The GRASSHOPPER IV, the many special measures taken to suppress dynamic signal crosstalk lead to a strongly improved resolution in the depth of the acoustical ambience reproduced and a lack of colorations due to non-musical harmonics.
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15: The special magnet:
After having done extensive research into the sonic properties of a vast set of magnet materials, for The GRASSHOPPER IV a special Aluminium Nickel Cobalt alloy was selected.
The applied AlNiCo magnet produces sonically superior results and, incorporated in The GRASSHOPPER IV version GLA, leads to a healthy 0.65 mV/channel output at 5.7 cm/sec eff. cutting-speed.
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16: Frequency response individually measured and included:
Included with each GRASSHOPPER IV is its own computer measured frequency response;
Due to circumstances frequency plots are temporarily unavailable.
Despite this, all new van den Hul cartridges and repairs of all brands undergo rigorous testing.
This response is measured using smallband pink noise; The result plotted is a 256-fold averaged response over each of 32 consecutive frequency bands.
This approach more realistically shows the real sound quality compared to the more “artificial methods” employing a sweeped bandpass filter; A sweeped filter removes all signals the cartridge produces as by-products of the tracking; Only the sinewave at the frequency under observation is measured, whereas our approach even shows the summation of all audible harmonic distortion. In our opinion this provides a more realistic record of the real cartridge quality.
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17: The sound:
The GRASSHOPPER IV’s sound quality is characterised by an extreme open and spacious reproduction; “very detailed with a lot of air between the instruments”. There is no trace of high-frequency harshness.
The stereo imaging is extremely accurate; Very often it is possible to detect the microphone technology applied during the recording.
Its exemplary low noise floor is “ear-opening”
Its ability to reproduce depth in soundstaging is enhanced in a way not experienced before.
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The GRASSHOPPER IV in your equipment:
18: Tone-arms and wiring:
The GRASSHOPPER IV is not at all critical with well constructed tone-arms. Exceptions are the very heavy arms made in the 50-s and 60-s.
Please pay attention to good tone-arm wires; Any signal quality loss in the arm leads is permanent; The tone-arm conductors and the cable connected to the tone arm (including its connectors) dramatically influence the perceived harshness.
Our MCS - 150 M (150 micron matched crystal silver) tone-arm wire is a good choice to upgrade your existing arm wiring.
Our product range includes many more components and cables/wires specially intended for your record player.
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19: GRASSHOPPER’s optimum tracking force setting differs amongst tone-arms:
It is NOT amazing that with different arms a different tracking-force needs to be set; This is the result of so called “standing” waves in the tone-arm; Also the friction in the bearings differs amongst tone-arms. The better the arm, the lower this tracking-force effect.
I have seen arms which behaved very well with settings of around 1.0 gram, whereas in other situations 1.7 gram was necessary, so don’t always blame the cartridge for this effect.
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20: Tracking-force and anti-skating setting with regards to extreme amplitudes:
The tracking-force should NOT be adjusted to track 80 - 90 microns anyhow because these are exceptional modulation amplitudes. Doing this will cause a too heavy mechanical load on the groove and will force the armature from its optimum position; (The armature’s best position is parallel to both the front-pole and the round rear-pole).
To account for the tracking-force induced armature/modulator misalignment, a small mechanical offset is built in during manufacturing.
Besides all this, the anti-skating setting needed to track 80 - 90 microns with normal cut records loads the outer groove (right channel) too heavy; Groove damage on the long run then is unavoidable.
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21: GRASSHOPPER phono preamp input impedance setting:
The input impedance setting of your equipment influences the sonic results to a large account;
When you prefer jazz with a high dynamic performance, the advised impedance setting is about 200 Ohms (or even somewhat higher). This especially when playing smaller groups of musicians like trios and quartets.
In case you prefer classical music and/or big orchestral recordings, set the input impedance to around 2000 Ohms or higher; Experimentally you can even go up to 47 Kohms.
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22: Running-in The GRASSHOPPER:
Each new unit needs a run-in time of about 200 hours playing. All units are set too tight because during the run-in time, the suspension needs to settle itself.
Inherently the cartridges are NOT built for best performance in their first hours; But your
3000 (minus 200 run-in-) hours left, will do much better than any other cartridge can offer!
During the run-in time, you will find that the tracking-force setting can be reduced somewhat. Please be prepared to do some experimentation with the tracking-force setting because any reduction will save your records more; But don’t overdo please.
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Setting-up The GRASSHOPPER IV:
23: First things first:
The set-up of The GRASSHOPPER IV is very easy; adjust overhang, position, tracking-force and the anti-skating (latter both typical values are printed on the included frequency response plot).
Due to circumstances frequency plots are temporarily unavailable.
Despite this, all new van den Hul cartridges and repairs of all brands undergo rigorous testing.
Typical values for the tracking-force and anti-skating are now written inside the cartridge’s storage box.
Also mind your phono preamp’s load impedance setting (see point 21 above).
It is recommended to lift the arm-support to achieve an angle of 2 - 4 degrees between the horizontal surface of the record and the arm with cartridge.
Use the included small spirit level to balance (in front-view of the cartridge) the horizontal tilt of the arm during actual playing. Also mind the platter’s exact levelling; I have seen many record players where the platter was not horizontal at all. This does not help to balance the static tracking-force equally between both groove walls.
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24: Fastening The GRASSHOPPER; be careful:
The non-magnetic Allen-head bolts don’t need to be tightened with brute force. Just fix them and that is enough. Overpowering the torque results in reduced mechanical damping from the polycarbonate body. Also the threads in the body will be damaged later.
There is no warranty on such an accident!
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A word for the customer:
25: The GRASSHOPPER, a reference standard:
Thanks to years of research and development, The GRASSHOPPER IV has become a standard and reference for both the amateur and professional. Thanks to the many technical innovations involved its sonic qualities are superior to any other phono system.
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26: Special customer demands/specifications:
Thanks to the many variations in materials available, it is always possible to build a unit to match the personal demands of the customer.
With these personalized cartridges both the wooden container and the included frequency response sheet mention the name of the customer it has been specially built for.
This option is exclusively available for The GRASSHOPPER III series, The GRASSHOPPER IV and The GRASSHOPPER “BEAUTY” versions.
The customer demands/specifications that can be taken into account when building a personalized GRASSHOPPER III, IV or GRASSHOPPER “BEAUTY” for instance are:
The tone-arm used, the preamp and load impedance used, a particular brand of records to be played, the type of music generally played (jazz being more dynamic and classical more spacious and detailed) and other personal/sound preferences.
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The after sales service:
27: Upgrade modifications from earlier version GRASSHOPPERS:
It is always possible to upgrade an early version of The GRASSHOPPER to a later version. This on special request of the customer and depending on the situation.
No other cartridge manufacturer offers this unique service!
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28: Cartridge repair service:
Damaged units are repaired with the same hands, eyes and experience used during the original build-up; The quality of repair is therefore very constant.
Furthermore, when having undergone a serious repair, you are free to return The GRASSHOPPER (or The GRASSHOPPER “BEAUTY” or The CONDOR or The COLIBRI) again for adjustments and fine-tuning, which might be desired after an anewed run-in time of 200 hours.
The repaircosts (f.i.: in case of an accident) are very low compared to the general charges by other companies (might there be any other repair service available in the world anyhow).
You will always get your own original unit returned with its same original sound quality. With a replacement unit you can doubt this for sure...
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29: Retune service after run-in:
Each owner can return his cartridge after the first 200 hours playing time. Besides adjustment and fine-tuning, any further complaints are dealt with as well (this provided the cartridge has not undergone any accidents or maltreatment).
Returning The GRASSHOPPER (or The GRASSHOPPER “BEAUTY” or The CONDOR or The COLIBRI) after its run-in is not a must, but merely an option.
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30: Old GRASSHOPPERS / Spare parts:
Even for the first GRASSHOPPERS (produced in 1978), our company keeps spare parts in stock.
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It is our experience that all the technical innovations, we have equipped The GRASSHOPPER IV with, will greatly help you emotionally and technically in enjoying your whole record collection.
We wish you many happy listening hours and a lot of extra pleasure with all your LPs (again and again).
Oene, August 1st. 1995
Signed: A.J. van den Hul.
Cartridge designer (CD).
© Copyright 1995 A.J. van den Hul B.V. All rights reserved.
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