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1#
发表于 2014-9-29 21:52:10 | 只看该作者
sme309唱臂+anna唱头,实测11hz-9hz抖动的厉害。其他很好。

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2#
发表于 2014-5-27 10:49:21 | 只看该作者
不劳而获,素质也好不到哪里啊

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唱臂和唱头组合后的谐振频率,两者如何互相配合

3#
发表于 2014-5-25 02:55:53 | 只看该作者 | 倒序看帖 | 打印 | 使用道具
我们经常会听某些烧友说,在别处听得效果很好的器材,搬回家后一出声却不是那么回事,甚至完全克隆声音也不一样。那是因为环境、器材的搭配、市电等等的差异造成的。而唱头也同样有这种现象,很多人说声音多好的头,或者这个唱头在朋友处听到很好听,自己买回一个一装上声音却变了样。除了前面提到的种种因素之外,还有一个很重要的问题,就是唱臂和唱头之间搭配的问题。唱针柔顺度、质量、谐振频率等因素无不直接影响着声音的好坏。而系统介绍这方面知识的文章却比较少。有看到一篇此类文章,却苦于E文不懂,一直不得其门而入。

请各位多分享这方面的经验。如有时间的话也请J版等懂英文的大侠帮忙翻译翻译,造福坛友,在此谢过!文章如下:

Tonearm/Cartridge Capability

For best performance, the tonearm and cartridge must be matched. All cartridges will not work with all tonearms, and vice versa. To insure a proper match, one must be aware of the mechanical specifications of both the arm and phono cartridge. To see how these characteristics interact and determine compatibility, we must first understand the dynamics of the relationship.

Any cartridge/tonearm combination will exhibit resonance at a specific frequency (or frequencies). This resonance is due to the interaction of the cartridge (acting as a spring), and the weight of the arm (acting as a mass). The "springiness" of the phono cartridge is described as compliance, the weight of the arm is specified in mass. As an example, a heavy weight on a light spring would obviously over-flex the spring, conversely, a light weight on a strong spring would not allow sufficient flexion.

At resonance, the arm/cartridge combination produces a dramatic rise in output. An increase of 3 to 6dB or more is common. This tremendous boost can cause severe problems if it occurs in the region of recorded music (above 2OHz), or in the area where record warps and rumble are problematic (below 5Hz). A cartridge/arm whose resonance occurs in the region above 2OHz can be influenced by music on the record. At this frequency a significant jump in output (resulting in a "bloated" or "tubby" sound) will be experienced. In extreme cases, the stylus may actually jump out of the groove. Similarly, a cartridge/arm combination that exhibits a resonance below the desired range will exaggerate the effects of record warps, or rumble produced by the turntable.

The goal in matching a specific cartridge and arm is to achieve a resonance in the 10 to 14Hz range. Some feel that limiting this range even further, to 9 to 11hZ, is best.

I've seen the following formula for calculating the resonant frequency of an arm/cartridge:
Resonant Frequency = 1000/[6.28*square root (M*C)]. Where M is the mass of the arm and cartridge and C is the compliance of the cartridge. As an example, if we had an arm/cartridge with a combined mass of 14g, and a cartridge with a compliance of 20, the resonant frequency would be 9.535.

This simple equation doesn't take into account all factors, including tonearm damping and, internal cartridge damping, but it will give you general idea of compatibility.

A decade ago, high-compliance cartridges were the rage and these needed to mate with very low mass tonearms. However, today’s heavier, lower-compliance phono cartridges (especially moving coils) have required tonearm designers/manufacturers to reorient themselves in the direction of medium to high-mass arms. Further, some of the currently available MC cartridges put back a tremendous amount of energy into the arm. This reflected energy takes the form of standing waves, which travel up and down the length of the tonearm, potentially creating mis-tracking problems and/or frequency dependent cancellation. A well designed tonearm will dissipate this energy, rather than reflecting it back to the cartridge. The ability of the arm to accomplish this will be dependent upon bearing design, internal damping and rigidity.

In a situation where a higher compliance cartridge is employed in a medium to high mass tonearm, the ill-effects of the match can be mitigated to some degree if the tonearm offers fluid damping. Here, a small paddle connected to the arm rests in a reservoir filled with viscous silicone fluid. This design feature restricts small, rapid motions of the arm (like the small undulations that would occur in a high-compliance cartridge), while providing unrestricted progress to the arm as it slowly traces across the record. This system also may improve the sound of some phono cartridges that offer little internal damping of their own.

The only way to accurately measure system resonance is with a calibrated low frequency test record and a chart recorder, or other sophisticated test equipment. Since most of us do not possess this capability, it is wise to do some preliminary homework in assessing the compatibility of any potential arm/cartridge combination. There are a few general "rules of thumb" that we need to consider:

* A tonearm whose effective mass is rated at 10 grams or below is considered low mass (e.g. early SME’s, Grace 747 etc.). A tonearm whose effective mass is rated between 11 and 25 grams is considered moderate mass (e.g. SME 309, IV, IV-Vi, V, Triplanar, Graham). Arms above 25 grams of mass are high mass in nature (Eminent Technology, Dynavector).

* A phono cartridge whose compliance is rated at 12 x l0ˉ6 or below, is considered low compliance. A cartridge whose compliance is rated between 13 x l0ˉ6 and 25 x l0ˉ6 is considered high to very high. Note: Another way of expressing compliance is um/mN. Here a rating of 5 to 10 is considered very low, 10 to 20 is moderate and above 35 is very high.

* Low mass arms mate well with both moderately high and very high compliance phono cartridges.

* Moderate mass tonearms are good companions for moderate to low compliance cartridges.

* If a low compliance cartridge is used with a low mass tonearm, undesirable resonances can occur in the audible range. Mistracking may also be a problem.

* When a high compliance cartridge is mated with a moderate mass tonearm, resonances in the infrasonic range may occur in addition to some unwanted high frequency damping.

It may not be possible in every case to accurately determine whether a particular cartridge is suited to a given tonearm by a simple glance at the specifications. This is especially true in border-line situations. However, poor combinations can be easily identified and avoided.

Several variables can influence our ability to accurately predict a match using the manufacturers supplied specifications. Some of these are: 1) The manufacturers specifications themselves can vary in accuracy due to differences in measurement techniques. 2) Sample to sample variation of the cartridge. 3) Differing amounts of internal damping of the cartridge or tonearm and 4) the age of the cartridge. The situation is further complicated by the fact that we should calculate both vertical and horizontal resonance points.

Happily, most of the popular, modem-day moving coil (and many moving magnet) cartridges and the current crop of medium mass tonearms represent a fairly good match. Exceptions do exist however, and we should be aware of the sonic pitfalls. An improperly matched cartridge and tonearm will not only sound poorly, it may even cause irreparable damage to records and stylus. So, it is well worth the effort in preliminary comparisons to determine the compatibility of the proposed cartridge and tonearm.

For further help in determining whether a particular cartridge is a good match for a given arm, consult the graph below (courtesy Ortofon).

Total (tonearm system) mass can be calculated by using the formula M = 10⁶ : (f2 x (2π)2 x C  where:

f - Cartridge resonance frequency in Hz
π - 3.14159265359...
C - Cartridge compliance in μm/mN

NB: Total (tonearm system) mass M is a sum of Mass of cartridge, Mass of headshell and screws and Effective mass of tone arm (all values in gram)


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4#
发表于 2014-5-25 22:20:46 | 只看该作者
可以,最好把原始连接给了。这里有点乱码。

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5#
发表于 2014-5-26 09:18:35 | 只看该作者
可以,最好把原始连接给了。这里有点乱码。
Jwang 发表于 2014-5-25 22:20

对,怎么没想到呢,还复制的这么麻烦。链接如下:
http://www.gcaudio.com/resources/howtos/tonearmcartridge.html

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6#
发表于 2014-5-26 09:31:16 | 只看该作者
这是玩黑胶需要认真了解的,期待J版翻译,谢谢。

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7#
发表于 2014-5-26 10:58:59 | 只看该作者
相信这里没多少人能懂
这一点是衡量是否真正高手的标准。
看了一下鸡肠,都是些纸面上的东西,也没说些真正有意义的
还是先把声音搞清楚是否“金字塔”再来谈吧!!

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8#
发表于 2014-5-26 21:31:24 | 只看该作者
有人可以帮忙算下:SME309唱臂和高度风的candenza blue唱头组合后的谐振频率?谢。

点评

在10HZ左右,非常理想了  发表于 2014-5-26 22:38

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9#
发表于 2014-5-27 06:37:22 | 只看该作者
回复 linyong336369 的帖子
谢合肥蒋鹏兄,如果要升级唱头,比如高度风的ANNA头,这支SME309还可以用吗?


   

点评

搭配anna在11HZ左右,没有问题的  发表于 2014-5-27 11:29

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10#
发表于 2014-5-27 10:21:38 | 只看该作者
人的素质好坏,一目了然啊

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11#
发表于 2014-6-7 12:57:57 | 只看该作者
这说明二手头臂不敢取

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12#
发表于 2014-6-7 10:05:22 | 只看该作者
抱歉,前段时间出去了。现上点部分的翻译。



任何臂和唱头的匹配都会在某个特定的频率或多个频率上产生谐振。这种谐振的产生是由于唱头(有如弹簧)和臂(有如质量)的相互作用而产生的。一个唱头的“弹跳性”就是唱头的顺从性(Compliance),臂的重量就是质量。比如,当一个较重的质重加在一个较低弹力的弹簧上,这就会过分地压迫这个弹簧。相反地,较轻的质量加在一个较强的弹簧上,这个弹簧就没有得到充分的弹跳。

在一个谐振点上,臂和唱头的匹配会导致输出急剧增加。36dB的增加是很普通的。这个在输出上的急剧增加如发生在音乐的频率范围内,20Hz以上,或发生在唱片变形和低频噪声的频率范围内(5Hz以下)会导致严重的问题。在这些音乐频率范围中,一个急剧增加的输出(导致庸肿或滞慢的音色)将会存在。在一些极端的状况下,就会产生跳针现象。同样,在唱片变形和低频噪声的频率范围中,这个急剧的输出也会加大唱片变形和低频噪声所带来的负面作用。



正确匹配臂和唱头的目标就是要使得其谐振频率在1014Hz内。有的人认为这个范围要更狭窄,最好的是911Hz内。

有人以下面的公式来计算谐振频率:

谐振频率=1000/[6.28·平方根(M·C)]。这里M是臂和唱头的质量。C是唱头的顺从性。例如,如臂和唱头的总质量为14 ,唱头的顺从性为20,谐振频率就等于9.535


这个简单化了的计算公式并没有考虑臂和唱头的阻尼因素,但仍可给你一个大致匹配性的估计。


十年前,高顺从性的唱头流行,这些唱头需要与低质量的臂匹配。然而现今的重质量和低顺从性的唱头(特别是MC唱头)需要唱臂设计者和厂家重新调整他们重臂和中等重量臂的设计方向。进一步地,当今某些MC唱头给臂传递很大的能量。这些反输回臂的能量形成臂中的驻波,这些驻波可能造成不能正确地循轨,或造成相关频率抵消。在一个设计良好的臂中必须扩散这种能量,而不是让这种能量反输回唱头。臂的这种能力取决臂的轴,内在的阻尼和刚度。


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