RARE PAIRE LUXMAN C300 ET M300:AMPLIFICATEUR ET À PÉROUSE

Rare paire Luxman C300 et M300:Amplificateur et préamplificateur (avec phono). État : "Occasion" En excellent état de fonctionnement, notez qu' il faudra remplacer une ampoule du voyant Led  "classe A". Voltage 220V. Les deux appareils sont visibles chez Jefferson Hifi à Pérouse où je les ai déposés. Livraison possible en France, en Europe,etc nous consulter pour les frais d'envoi internationaux. Le M300 a été produit en même temps que la série C300. Je crois qu’il n’en a été produit que 2000 dans le monde. C’est non seulement une paire de collection, mais le haut de gamme des luxman des années 1980. Ils sont les dernières combinaisons pré/ampli, à avoir été fabriquées sans implication de Alpine(qui a ensuite  modifié sérieusement la qualité Luxman  hélas.). ils ont été primés "produit de l'année" au début des années 80.  Le M300 se laisse utiliser soit en classe A, où il développe 2x42 w sous 8 ohms en classe A, ou alors 172w en classe AB sous 8 ohms. Comme toujours chez Luxman, on peut espérer une dizainede watts supplémentaires dans chaque modes, vu qu'ils utilisent unsystème de mesure très strict sur leurs fiches techniques. Il faut surtout savoir qu’il ne faut basculer de classe AB en classe A que à l’arrêt, en redémarrage à froid.  Voici  les caractéristiques techniques (https://audio-database.com/LUXMANALPINE-LUXMAN/amp/m-300-e.html) et https://audio-database.com/LUXMANALPINE-LUXMAN/amp/c-300-e.html 1)Préampli C300: Frequency response: 0.5Hz to 140kHz   Total harmonic distortion: 0.005% Input sensitivity: 0.09mV (MC), 2mV (MM), 140mV (line)      Signal to noise ratio: 80dB (MM), 100dB (line) Output: 140mV (line), 1V (Pre out), 20V (Pre out Max)  Dimensions: 478 x 163 x 384mm     Weight: 9kg 2)amplificateur M300 Form Duo beta plusX poweramplifier Succession effectiveoutput (20Hz - 20kHz, both channel simultaneous operation) Class-A: 40W+40W (8ohms) AB class: 270W+270W (4ohms) 170W+170W (8ohms) THD (8 ohms) 20Hz- 20kHz-3dB Class-A: 0.005% or less AB class: 0.005% or less Cross modulationdistortion (8 ohms) 60Hz: 7kHz=4:1, -3dB Class-A: 0.005% or less AB class: 0.005% or less Output bandwidth Class-A: 10Hz-100kH-3dB(0.015% of distortion) AB class: 10Hz - -100kHz three dB(0.04% of distortion) Frequency characteristic 10hz-100kHz-1dB (aClass-A and AB class) Input sensitivity Class-A: 0.45V ABclass: 1V Input impedance 50kohm (a Class-A and ABclass) SN ratio (IHF-Acorrection) Class-A: 115dB ABclass: 120dB Remains noise (IHF-Acorrection) 30 microvolts (a Class-Aand AB class) Dumping factor 120 (1kHz, 8 ohms, aClass-A, and AB class) Protection network DC drift detectionspeaker protection network Overcurrent detection amplifierprotection network Attachment Circuit operationswitchpoint (indicator) Peek indicator Inputattenuator Headset jack Speaker-off switchpoint(indicator) Line phase sensor Supply voltage AC100V, 50Hz/60Hz Power consumption (Electrical Appliance and Material Control Law) Class-A: 420W ABclass: 430W Dimensions Width 478x height 214xdepth of 484mm Weight 30kg Stereo power amplifier which adopted the Duo beta plusX circuitry. In order to control NFB of an amplifier circuitry appropriately, the Duo beta circuitry was developed and it is adopted as M-300. After this makes amplifier to the extent that it is used also from a nakedness property as it was, it adds proper-quantity NFB and DC servo as finish of a tone quality, and is suppressing the transitional distortion of a supression of play sound, TIM, etc. by superfluous NFB etc. Furthermore, in M-300, the thought of a suitable control is introduced also into a power circuit, and it is considered as the power-source Duo beta plusX. At plusX, the stability of a comfortable tone quality and an operation is reconciled because the bottom gives controlling force calmly on the assumption that a generous power-source part. M-300 can change and use a Class-A and AB class. The Class-A operation has a structure which amplifies a signal wave form as it is. Therefore, it becomes unrelated to switching distortion or crossover distortion, and does not have the cause that it is distorted in addition to an element's own linearity. In M-300, the Class-A operation excellent in adopting a Duo beta as LAPT which excelled [element] in the high region property, and an amplifier circuitry, and adopting plusX as a power circuit is realized. In AB class, Oide power which drives transitional distortion below into a limit of measurement in pursuit of a nakedness property also in an operation, and is not made in a Class-A operation on it is realized. At the time of a switching of a Class-A / AB class, in a performance, sound does not break off and a noise is not generated, either. Circuitry constituted all the amplification stages from a push-pull circuit from the input stage to the output stage, and the amplifier which was excellent in the nakedness property which will be the requisite for a Duo beta circuitry is realized. The pre-driver stage is making the input stage the transistor which was excellent in the high region property with the cascode interconnection with the stream composition of the cascode bootstrap and the differential push pull by complimentary FET of a Pch type and a Nch type. And the driver stage and the power stage are considered as the push pull stream composition by a three-step Darlington connection. A linearity makes an output element high speed power transistor linear arithmetic processor-T which was well excellent in the high region property with a triple push pull stream composition, and the electric current is sent. In this way, the static characteristics and the dynamic behavior improved. And proper-quantity NFB and DC servo are added. The power-source part had the twin monophonic stream composition of right-and-left full independence, and has acquired the merit of a linearity covering all the bands, and the outstanding crosstalk property. The power transformer is performing and using the coil mandatory adopted and put into practice among the object for Rch, and two Lch. First, the power stage and the drive stage were made into another coil, and also the primary side and secondary side has unified the orientation of a coil. This is because it is checking having influence on play sound with the potential (polarity) which a transformer begins to roll, rolls and the last each has between opposite groundings. Moreover, four right and left adopt the type only with a capacity of 12,000 micro F for an audio as a filter capacitor, and low-impedance-ization of the power-source part is attained to it. In order to cope with the rush current which becomes large as the capacity of a power-source part becomes large, the rushes current preventing circuitry is adopted. The speaker protection network and the amplifier protection network are carried. The internal organs of the speaker protection network which detects DC output in an output-terminal and separates an output are carried out. Furthermore, when the speaker code etc. short-circuits, even if there is a big input, an amplifier circuitry is protected or the electric-current preventing circuitry is carried. After the elements currently used examine, it is using it, carrying out a tone-quality mandatory strictly uniquely. The film capacitor generally called non-polar is also arranging a polarity etc., and the capacitor is carrying out the tone-quality mandatory strictly. Moreover, the precision succession good transformation Detent volume excellent in the tone quality and a feeling of an operation is adopted as input attenuator. Furthermore, in terminals, the small gilding pin jack of contact resistance was adopted as the input terminal, and the large-sized screw type is adopted as a speaker termination. The product line was packed into the shortest distance, and also it has chosen high materials of the tone-quality effect, such as a shielded cable of oxygen free high conductivity copper and 500 core. Moreover, in order to suppress an elevation of the source impedance of the pattern side of a substrate, the power bus by a copper plate was adopted and the performance of a power source is employed efficiently. The line phase sensor is carried, by the functionality which detects this polarity, the polarity of the equipment was unified and the tone quality is improved. The indicator turned on at the clipping point of an output is carried, and a peek can be supervised.