Silver NAD S250 Five Channel Power Amplifier 125w x 5 - Versión para impresión +- Foros de Supervaca.com (http://foro.supervaca.com) +-- Foro: Discusión General de Home Theater (http://foro.supervaca.com/forumdisplay.php?fid=4) +--- Foro: Equipo de Home Theater (http://foro.supervaca.com/forumdisplay.php?fid=10) +--- Tema: Silver NAD S250 Five Channel Power Amplifier 125w x 5 (/showthread.php?tid=3417)

Silver NAD S250 Five Channel Power Amplifier 125w x 5 - carlosvp - 09-29-2004 Hola a todos, Como ven este amplificador multicanal de la linea Silver Nad ??? The NAD S250 is the perfect match for our S170 surround preamp/processor. It is a powerful, THX-certified 5-channel amplifier with transparent, wide-range sound that is clean and detailed from its solid, extended bass to its "airy," accurate high end. It will drive virtually any array of home theatre speakers to their full potential in almost any home listening environment. Its feature list includes: 125W x 5 Continuous Power (8 ohms); all channels driven simultaneously 200W x 2 Continuous Power (8 ohms); two channels driven simultaneously Low loss, massive Holmgren toroidal mains transformer 12 volt trigger for automated ON/OFF operation Input gain control for each individual channel THX certified Mono-block, Modular construction All inputs Gold Plated RCA Differential, Class A input circuit topology Soft Clipping A closer look The demanding job of complimenting the S170 preamp/processor with a five-channel power amp of sufficient power for large Home Theatre layouts — with enough reserves for even lower-sensitivity 5.1-channel speaker arrays — is a challenge met brilliantly by the S250 surround power amplifier. It maintains the Silver Series' uncompromising standards for sonic excellence with the S250, whose five fully independent 125-watt channels supply the performance, stability and reliability needed to earn the demanding THX Ultra certification with ease. The S250 employs monoblock construction for each of its five channels. Every element of each channel's circuitry except for the power transformer is fully independent, eliminating inter-channel influences as a concern. Like its stereo predecessor, the Silver Series S200, the five-channel S250 is stable and musical even into "unreasonable" loudspeaker loads. An immense edition of NAD's unique, extremely low-noise/low-hum "Holmgren" type toroidal power transformer—a significant advance over conventional toroid components — provides the five monoblock amplifier sections with over 60,000 uF of storage capacitance to ensure an ample reserve of power for even the most demanding music and film soundtracks. Each section features pure-differential, fully Class A input and driver stage circuits, and a high-current output-stage design, employing the same high speed output devices as used in the S200 to achieve superb dynamic quality. The result is musical detail, impact, and soundstage stability and depth unmatched by multi-channel amps of two and three times the S250's price. And our proprietary Soft Clipping (defeatable) maintains sonic quality under even severe overdrive conditions. Individual gain adjustment for each channel promotes easy, accurate system configuration, as does the S250's integral 12-volt-trigger turn-on response, which features a Sophisticated "zero crossing" triad rather than the more common mechanical relay to promote long component life and reduced turn-on surge. The multi-channel amplifier delivers its output via very heavy-duty "five-way" connectors. NAD was the first company to introduce a THX-certified power amplifier. It is therefore no surprise that the NAD S250 passes Lucas Films' stringent THX requirements with flying colours. The S250 will handle all dynamics with ease and yet retain every subtle detail in the most demanding THX Dolby Surround systems. The S250 incorporates NAD's unique, defeatable Soft-Clipping circuitry for all five channels. Any amplifier can be overdriven if asked to play too loud, exceeding its maximum rated output power). Under such circumstances, amplifiers will produce extremely high levels of distortion, which, besides sounding very unpleasant, can damage your loudspeakers. The Soft Clipping circuit will curtail such distortion and minimise the risk of damage to speakers. This is particularly important with AV software that often consists of very dynamic and sustained outbursts in which, unlike music, it is difficult to hear this potentially damaging distortion. Ruggedness and in-system reliability are critical to successful custom-installed systems. This amplifier utilises a combination of fuse and electronic non-intrusive protection: dependable, fail-safe, and sonically benign. Each channel is protected against excess temperature, DC fault and loudspeaker short-circuit. Most important of all, the S250's inherently conservative, high-voltage/high-current output-stage engineering has been designed for years of high-performance, trouble-free service. S250 multichannel power amplifier Specifications Power Amp Section Continuous Average Power Output at 8 ohms 1 5 x 125W (21.0dBW) Rated distortion (THD 20Hz-20kHz) <0.05% Clipping power 0.05% IHF power dynamic headroom at 8 ohms +1.4dB IHF power dynamic power 8 ohms 172W (22.4dBW) 4 ohms 273W (24.4dBW) Damping factor ref. 8 ohms, 50Hz >300 Input impedance (rated power into 8 ohms) 50k ohms Input sensitivity 1.1 V Voltage gain 29.0dB Frequency response 20Hz-20kHz +0, -0.2dB 2Hz to 100kHz -3dB Signal/noise ratio ref. 1W 95dB (ref. rated power) 125dB Physical Specifications Dimensions (W x H x D) 17 3/4 x 5 15/16 x 15 9/16" (450 x 150 x 395mm) Net weight 41.8 lbs (19.0kg) Shipping weight 46.30 lbs (21.0kg) S250 Amplifier List $2500 Now $999 Saludos Carlos Villegas - Jorge E. López H. - 09-29-2004 Carlos, Me alegra que hayas presentadoe ste amplificador, ya que es equivalente al Rotel RMB-1075 que tengo actualmente (120 watts x 5 canales). Me parece que las especificaciones crudas hablan de un buen amplificador en todos los terrenos, aunque lamentablemente no menciona cuál es la capacidad del transformador. Por el peso, supongo que debe ser mayor a 1.5 kVA, ya que mi Rotel pesa 3 kilos menos y ésta es la capacidad de su transformador. Por supuesto, el peso no siempre habla de la calidad de un equipo. Puntos fuertes de este NAD: a) Al parecer tiene capacitores independientes para cada canal, lo cual es excelente. b) El famoso "soft clipping", tecnología propietaria de NAD. c) Ganacia ajustable para cada canal, lo cual es muy bueno para aclibrar apropiadamente el equipo si tu pre/pro no te lo permitiera. d) Uso de TRIac en lugar de relevador (el triac es más robusto ya que los relevadores se desgastan rápido si tienen que abrir y cerra continuamente). En fin. Sería interesante conocer dos parámetros importantes: a) Cuál es el "fidelity firewall" del amplificador, es decir, cuál es la máxima potencia que entrega sin que haya distorsión audible. b) Cuál es su factor de amoriguamiento (damping factor) en toda la frecuencia audible. esto es imporante, ya que aunque el valor presentado es bueno, se muestra sólo para 50 Hz. Por ejemplo, mi Rotel 1075 tiene un amping factor de 180 pero en el intervalo entre 20 y 20,000 Hz, lo cual es excelente. En fin, este NAD se ve interesante. Me pregunto si lo están vendiendo en México y cuánto cuesta por acá (Sala Chopin es el dealer autorizado en México). Por supuesto, el juicio final lo da el escucharlo en vivo y a todo color. Saludos! - carlosvp - 09-30-2004 Hola Jorge, Me anime a mostrar este amplificador porque pienso que muchos en el foro deseamos integrar un sistema multicanal de calidad que nos permita disfrutar tambien musica en estereo. Cuando encontre la promocion de la tienda Saturday Audio me anime mucho, ya que NAD siempre ha sido catalogado como una marca musical y en especial la linea Silver NAD ha tenido muy buenos reviews. Cuando leo las especificaciones de un amplificador, tengo la mania de ver antes que nada 2 cosas: su peso y el damping factor. Tambien note que solo dan el valor a los 50 hz y me parece que es una forma de maquillar este parametro para declarar un valor realmente alto. Esta bestia pesa 19 kgs. y a menos que por dentro le adicionaran de peso extra, habla muy bien de su construccion. No he visto fotos de su interior, pero seguro contara con un transformador generoso, como los utilizados por el amigo Klaus en sus amplificadores Odyssey. Tenia en mente invertir en un nuevo sistema estereo basado en un amplificador Odyssey Stratos y un pre de bulbos aun por definir, pero cada vez disfruto mas mi sistema de HT y ahora estoy dudando seriamente que hacer. Saludos Carlos - Edmundo - 09-30-2004 No se mucho de amplificadores, pero si esta de $2,500 dolares a $1,000 debe valer la pena :lol: :lol: :lol: Avisanos si te animas