闲得慌，再发一贴，侃侃luxma M_4000A搭配雨后焕发出的甜美迷人音色！！！★★★★...

叶荣玉

      {:soso_e104:}闲得慌，{:soso_e113:}再发一贴，{:soso_e113:}侃侃luxman M-4000a搭配雨后初晴MKIII被焕发出的甜美迷人音色！！！
   平时偶尔翻阅国外网站，得悉日本力士功放搭配英国雨后初晴音箱，效果奇好。尤其是古董级的力士放大器最优。手头正好有一对雨后初晴MKIII音箱。搜索淘到有好几个商家在出售luxman M-4000，于是，做足功课后，就立刻下单。后缀有a标的M-4000a。喇叭输出端子为平衡链接，且言明连机器一起奉送，毫不忧虑就拿下了。



Luxman M-4000/M-4000A  

The M-4000 is the smaller version of the M-6000 masterpiece, somewhat more affordable, but circuit-wise fully identical so it also is a Tim de Paravinci design.

Pioneer at the same time, 1974, also called on a non-japanese designer for its upcoming HPMseries while, in 1973, Marantz was doing the very opposite with the Model 1060, a fully Marantz-Japan (aka SRC) designed amplifier with no US roots.

The M-4000 was launched a few months after the original M-6000, also celebrating the 50th anniversary of the brand's foundation as radio amateur shop in a supermarket in 1925.
The circuit of the M-4000 is a 2-stage constant current differential amp ending in triple push-pull pure complementary OCL output with an emitter-follower in between the differential driver stage in Class A and the output stage in Class B.
The dual power-supply, the very big power-supply, feeds the circuits with two 400VAtransformers and four 15,000μF / 100V caps and separate windings used for the driver and output stages.
Protection schemes were particularily cared for - there are four !
DC-drift sensing when ± 3V are detected at the speaker terminals, power transistor failure sensing shuts everything down, high temp sensing shuts everything down again when heatsink temp rises above 100°C and over-current sensing when DC current appears with the signal and is detected by the comparator.
Meters are doubled-up with the average levels handled by the VU and the peak spots by the six added red LEDs. If you see the +3dB light up, you'll know you've just hit 1,2kW but you won't hear anything anymore.
These peaky LEDs can be switched to x10 scale or be turned off completely and this flashy addition was, visually, done very intelligently.
Input level "setters" allow to balance respective levels in optimal ranges for both preamplifier and amplifier between -20dB and 0dB in 1dBsteps. This is done with stepped metalized film precision pots.
The M-4000, visually, is simply stunning and its design is on par with the circuit, perhaps even better - that says a lot.
Before vanishing in favor of the M-300, the M-4000 briefly saw an updated M-4000A version made for the C-5000A master preamplifier.
The M-4000A sported MOS-FETs, Lux's Duo-Beta scheme, a pair of XLR plugs (as speaker terminals), a better s/n ratio by 2dB and 2 more kilos on the balance. Also changed : the LEDmeters' diffusion plate (smaller and much less diffused) and the addition of the Duo-ß logo south-west of the L meter.
If the original M-4000 is already excellent and sold in sizeable quantities, the M-4000A is a true gem that is unfortunately very rare due to a very limited availabilty.
A real M-4000 at hifi-do's and an M-4000A there too.

==

骑马观花

交易区新帖推荐

很好
鸡精，味精，古月粉
全糊一块儿
说不准成了一道名菜

深圳仔

不要老旧垃圾！

叶荣玉

深圳仔 发表于 2015-9-26 15:52
不要老旧垃圾！

有的玩，就不错啦   

叶荣玉

{:soso_e112:}

LUXMAN M-4000A 398,000yen(January, 1980 release) Description Stereo power amplifier which used as the base the large-sized power amplifier M-4000 put on the market in 1975, made the newest technology the injection, and raised completeness further. The Duo beta circuitry original with LUX is carried for the improvement in a tone quality. In this circuitry, NFB of a suitable quantity for all the bands was applied, and DC servo circuitry is combined with super-low-pass one. By this, the character of the tone quality of all the bands was decided, the revise was added to the super-low-pass one besides an audio frequency band, and the settlement as an overall has been obtained. Moreover, in order to cancel the vicious circle of applying NFB in large quantities in order that gain may become high and may stop this so that the nakedness property of amplifier is improved, and carrying out a tone-quality failure, a nakedness property is excellent, and amplifier with little gain is made, and NFB is reduced sharply. As a result, the TIM distortion by the difference of how to require NFB in low-pass and a high region is removed. Furthermore, DC servo circuitry has realized the low-pass play which cut the super-low-pass noise and became tight, and also enlarges a super-low-pass dumping factor, and is raising the resolution of a low-pass play. Moreover, the problem of DC drift was solved and the effect has been acquired also to the speaker protection. While adopting four power MOS FET as an output stage and sending 300mA or more of bias currents, the notchless class A operation which does not carry out a switching operation is made combining the high-speed driver circuitry. In order that gain suitable for a Duo beta circuitry may realize the low good amplifier of a nakedness property, a thorough review of circuitry and a material is performed and the nakedness property is pursued. The first rank constitutes the cascode differential amplifier by FET strong against a transition of ambient temperature or a voltage dual monolithic type, and the combination of a high resisting pressure low-noise transistor, and has acquired the outstanding high region property. Moreover, the predrive stage adds a current mirror load intensity to a cascode differential-amplifier circuitry, and is aiming at the modification of a linearity. And the drive stage and an output stage constituted the pure complimentary SEPP circuit, and have taken out the Oide power by the low distortion. In these results, the naked distortion serves as outstanding amplifier with which the naked frequency characteristic was extended on a single figure to one fifth of amplifier conventionally. In order to carry out thorough exclusion of the interference between the right-and-left channels of an input signal, the power transformer of right-and-left full independence is begun, all the circuitries are formed into a twin monophonic recording, and it is considered as the structure which unified monophonic amplifier x2. Moreover, the simplification of the product line is attained, the substrate was blocked and secular change have adopted little reliable glass epoxy as a material. Furthermore, careful selection adoption of the connector of hi-reliability often used for communication equipment etc. is carried out, it plates with gold also in the termination side by the side of a substrate, and the robustness of the contact is improved to the terminal area of the substrate. Two good large-sized toroidal transformers of a regulation were adopted as the power-source part, and it has combined with the high-speed constant-voltage regulated power supply of the twin monophonic stream composition. An output stage constant-voltage-ized even the pre-driver stage, and has made the powerful power-source part to it while it carries out the careful selection using of the tone-quality measure type mass capacitor of 15,000 micro Fx2. Three-fold protection network is carried in M-4000A. One is a speaker protection network, excessive DC input enters, and if DC component is detected by the output-terminal, it will work. Moreover, when the Dainyuu power is added short-circuited +- of a speaker termination, amplifier is protected doubly in the protection network by the overcurrent detection for preventing a destructive of a transistor, and the protection network by the fuse fusing detection for power transistors. With the metals coat type, the Detent volume of the same type as a high-class Attenuator is adopted. The chimney type heat sink made from aluminum die-casting is adopted. The Subsonic Filter is carried, and while giving the functionality which cuts the super-low-pass noise leading to cross modulation distortion, it is considered as the measure against DC input. The canon connector is adopted as an output-terminal, while plating with gold at an input terminal and improving a robustness. The grounding terminal is carried. Rating of a mode For Duo beta circuit stereo power amplifier cscession effective output (20Hz - 20kHz) Both channel concurrent / one-side-channel operation 270W+270W (4ohms) 180W+180W (8ohms) THD (8 ohms, 20Hz - 20kHz) 0.008% or less (180W) Cross modulation distortion (8 ohms, 60Hz:7kHz=4:1) 0.008% or less (180W) Frequency characteristic 100kHz [ 3Hz - ]-less than 1dB Output bandwidth 10Hz - -100kHz three dB (0.1%) ]Input sensitivity/impedance 600mV/50kohm SN ratio (IHF-A correction) 116dB or more Remains noise 0.2mV or less Crosstalk (Volume maxima) -100dB or less (1kHz) - 80dB or less (20Hz - 20kHz) Dumping factor 100 (at the time of an 8-ohm load intensity) Protection network The speaker protection network by a speaker termination DC drift The amplifier protection network by overcurrent detection The amplifier protection network by the fuse fusing detection for power transistors Attachment Power meter Peek indicator (it is with the switchpoint of on/off of a peek indicator) Meter sensitivity changeover switch (0dB-20dB) The input level set of 22 points of 1dB space-characters Detent volume adoption Supply voltage AC100V, 50Hz/60Hz Power consumption (Electrical Appliance and Material Control Law) 520W Dimensions Width 491x height 181x depth of 390mm Weight 30kg

叶荣玉

交易区新帖推荐

我敢断言：luxman  M-4000后级再过20年也不会坏的！！！！何以见得？


请跟我仔细看图！看到了吗？从裸露的机器图片中，我告诉你们一个信息，那就该机器内部的主要线路板采取直接可插式安装，亦是说，想看看线路板有无问题时，就可以随时随地轻易的将线路板从插槽中拆卸下来检查维修。也就是说，你想怎么整就怎么整它的。拔下的线路板，焊工极其的考究，至今尚无一处有脱焊、虚焊等不良现象发现，这和我检修过的同样是可插式线路板的金嗓子P-300S后级功放，居然luxman'有着先天的优势让人意想不到。该机器底部的走线整齐划一，接头处全部手工螺丝拧接。拧接点光滑铮亮。走线极其工整，有条不紊，仅此手工技术，就在当下，也属难得。M-4000电源水塘滤波电容耐压值是80V，M-4000a则是100v耐压，线路也做了改进。100V耐压的大水塘，不仅在当年哪怕是现在，价格也是很高昂的。线路板上所有电解都是密封胶密封后焊接的，这也就是说电解自安装之日起就一直处于密闭的不透气状。这样做最大的好处是电解电容不易干涸。还有就是所有功率管都被锁死在裸露在外的散热器上，这样更利于降低机器内部的温度。由此可见，该机再过20年，它也不会死！！！{:soso_e135:}

死磕

问题是，用不了20年你就没了。这种设计最讨厌的是，电路板在机器上的时候不好测量，从机器上拿下来有没法测工作状态。
这种机器的维修检测需要专用的工装。另外，电解电容的失效不全是因为干枯才会造成的。
这么些年了一点进步都没有，还是弄一堆洋垃圾自吹自擂。

花钱买乐乎

死磕 发表于 2015-9-27 10:49
问题是，用不了20年你就没了。这种设计最讨厌的是，电路板在机器上的时候不好测量，从机器上拿下来有没法测 ...

现在的机机不论做工和质量都达不到以前的严谨！

叶荣玉

深圳仔

不被忽悠，不玩洋垃圾，特别是日本的垃圾，核辐射....身体健康最重要

jason8

叶大侠好，能赐教些三脚猫的功夫也是好

zhjzhjzhj

死磕 发表于 2015-9-27 10:49
问题是，用不了20年你就没了。这种设计最讨厌的是，电路板在机器上的时候不好测量，从机器上拿下来有没法测 ...

电子原件都是有寿命的

zhjzhjzhj

深圳仔 发表于 2015-9-27 16:46
不被忽悠，不玩洋垃圾，特别是日本的垃圾，核辐射....身体健康最重要

kobehu

楼主胆机看起来不错？哪位大师的？