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Best Counterweight Position?

Some might say "At the opposite end from the head shell" :-)

But how can you be sure if the position that gives you the correct stylus pressure is the best position for your cartridge?

What I recently discovered on my setup is the further back I placed the weight the more lateral resistance was applied to the cartridge, changing the sound for the better.

To accomplish this required me to change the effective mass of the tone arm - several times.

One very simple way to accomplish this was to remove a piece of the outer cable insulation from a thick mains cable. Making a cut down the length of the sleeve allowed me to place it on the arm near the cartridge and the sleeve gripped the arm without allowing any movement.

I then proceeded to recalibrate the tracking force by repositioning the weight more towards the rear of the arm - away from the pivot point

The first attempt made the sound bloated and displayed some nasty effects, so I simply cut off a piece of the Insulation and recalibrated the tracking force.

Once the best sound is achieved you can then make the adjustment permanent by adding a headshell weight that results in the counterweight being placed in the same distance from the pivot point of the arm.

The head shell weight I started with matched the weight of the insulation and then did some fine tuning to get the weight into the correct position.

Now, there are some that will point out that this will change the effective mass of the arm and may upset the delicate balance of tone arm/cartridge compliance matching.

Well, that is true if the cartridge is matched "exactly" to the tone arm, fact is there is most always a fair bit of latitude in this area, allowing for some room for improvement.

If you are of the belief that the effective mass of the arm should not be changed, then, using a lighter counter balance weight will allow you to place it further back.

In my case I have a Rega RB250 and a Denon DL103, which is not "the best" match, but by adding some mass to the tone arm this cartridge really performs extremely well and brought the compliance/tone arm match closer to the recommended settings.

Yes, the compliance match is one reason for the better sound, but getting the counter weight further from the pivot point also made the DL103 perform much better IMHO :-)

What improvements did I notice - much smoother reproduction in the high frequencies, more texture in the bass frequencies, improved imaging and bigger sound.

Cost - just some of my time and the headshell weight, about $10.

Something to try on those cold winter nights :-)
williewonka
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rauliruegas
13,064 posts
 
Dear Williewonka: +++++ " Also, your "doubt" appears to be based on the assertion that the best position for all counterweights is close to the pivot point. However, you are not able to experience the improvements I have actually heard. " +++++

things are that we already ( after 5+ years. ) finished our self tonearm design, a unique one.

Well, I respect A:J Conti as a person and audio item designer. First than all IMHO there is no perfect audio items designs that performs perfect during playback, always exist trade-offs and tonearms are no exception.

What MR. Conti stated is not only not something new but " things " that other tonearm designers already took in count. There are several tonearm designs that already made it that as: Moerch ( an unipivot design as the Vector. ), Audiocraft, Sony, Triplanar, Da Vinci, Talea MS, etc, etc.

now, what could be the trade-offs on what your linked information has?

IMHO a tonearm " exist " to fulfil the cartridge asked needs during playback and not only for hold and set up the cartridge parameters as: VTA/SRA/VTF/overhang/AS;etc but to help that the cartridge can ride/track in better way the precious information recorded in the LP grooves.

This " full " recovery of the recorded information is a TITANIC task for say the least where that tiny cartridge stylus must not only to move " freely " at random according to each one LP groove and stay always in touch with the grooves but that ( Here each one cartridge designer is the first responsable to makes its " job " for that could happen. )at " random " direction movements be/happen with the faster response by the cartridge stylus.

as longer effective lenght tonearm and as more rearwards the tonearm counterweight as worst will be the posibility to give ( the right and precise ) the cartridge stylus what it's asking, what say I? not asking but " screaming " for: the fastest tonearm response.
This is a main target, IMHO, for any tonearm design.

Try to tame the cartridge signal sound trhough adding some kind of colorations/distortions through the counterweight manipulation ( other that be near that 10hz resonance frequency that posted T.wins. ) is only that: a manipulation that IMHO does not helps to fufil the cartridge needs but to " fulfil " our imperfect " ears " with more distortionss and less accurate musical information.

My goal is to recovery the " 100% " of the recorded musical information adding and loosing the less. If what I'm recovering likes me or not it is not important what IMHO isimportant is to have the full informatiuon down there and if you don't like it instead to tame it adding more distortions/colorations analize where in my audio system chain I can improve to achieve a real better quality performance level adding no single distortions/colorations but trying to go lower in that regards.

Of course that is my main target that it is obvious you don't have. Each one of us have our each one targets and I respect yours as the MR. Conti or any one person here.

regards and enjoy the music,
R.
williewonka OP
3,075 posts
 
Raul - a lofty goal indeed - I wish you every success in your endeavours and hope you achieve them. You seem to be well on the way based on your profile.

My goal - get the best sound possible from my very modest system - gauged by my own ears.

One last question - why 10 Hz - I've read various target value like 8-12 hz and several that mention 8_10 Hz

One reference stated 10 Hz was the frequency at which the arm starts to wobble. Any truth to that?

Many thanks
tonywinsc
583 posts
 
The goal of the tonearm is to provide a stable platform for the phono cartridge to track in the groove at the correct geometry. So the first order of business is to set up the tonearm overhang and alignment so that the stylus remains at the tangent point in the groove and aligned square to the groove from start to finish. Next, the tonearm is suspended over the record with near zero friction and coupled to the stylus through a spring suspension. In addition, forces are acting on the stylus in all three dimensions. The stylus is being pushed to the left and right, pulled on and pushed up and down (warps in the record). The tonearm and cartridge system is a classic spring/mass system which responds to this harmonic input. This spring mass system has a resonance point which is where small energy inputs cause large energy outputs. If the tonearm system resonance is too low, ie. less than 8 Hz, it will become sensitive to footfalls and the rotating record. The record is rotating at 0.5555Hz. 10 times that is 5.5555Hz which is a safe range away from resonance. 45 rpm puts the record rotation at 0.75 Hz so 7.5Hz minimum for the tonearm would be a safe range. Much higher than 10 Hz can cause the tonearm to become very lively with warps in the record and is also getting close to the 20Hz signals in the grooves. It may or may not skip but the lows can get muddy because the arm is responding to those low frequency signals in the record grooves. Record runout creates a 0.55Hz at 33 1/3 rpm and 0.75Hz at 45 rpm lateral sway in the tonearm. This is another reason to keep your tonearm/cartridge system response around 10Hz.
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rauliruegas
13,064 posts
 
in my post we can read: ++++ " at " random " direction movements be/happen with the faster response by the cartridge stylus ++++++

a mistake, it has to say:

++++ that at " random " direction movements be/happen with the faster response by the cartridge stylus/tonearm assembled. ++

Btw, of course I tested several counterweight tonearm positions and between other things that's one reason I posted what I posted.

R.
williewonka OP
3,075 posts
 
Thanks guys for all your input.

My turntable has never sounded so good :-)
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