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  Stereo Products > Classic 250 Amplifier Classic 250 More Info Starting at just $4,995.00!  Two years in the design and development phase.Hundreds and hundreds of hours of listening, testing, head scratching and designing. But we're finally ready to unveil our finest work of art ever. The Classic 250 ships in August for those who have pre-ordered it. The Classic 250 power amplifier. State of the art in every respect, the Classic 250 is our definitive statement in an all analog power amplifier. 250 watts per channel into 8 Ohms stereo, 500 watts per channel into 4 Ohms stereo, and a whopping 1000 watts into 8 Ohms and 1800 watts into 4 Ohms for mono operation. Pure and emotionally charged performance  You turn on the Classic 250. Warm it up. Dim the lights. Prepare to be stunned. Unfettered dynamic range unlike anything you’ve ever experienced: a dynamic passage rolls through your living room like the proverbial freight train with all the authority in the world. And yet, this amp is sweet and open and delicate when the music demands it. The C250 is poetic and lush in its presentation of beauty, yet almost frightening in its rendition of power and majesty. Truly, this is a world class amplifier unlike anything we have ever made. In fact, a true Classic. The chassis is pure sex Based on the classic lines of the P600 Power Plant, the C250 was sculpted by artisan Alex Rasmussen to show off what’s  inside of this treasure.Thick aluminum slabs are found throughout the piece. From it’s quarter inch thick top plate, inch thick feet, to it’s beautifully crafted front panel, the C250 is a true high-end experience. This is built in true 'battleship' fashion. A no-holds barred approach, this 95 pound audio sculpture is simply magnificent in its build quality and attention to detail. The side heat sinks are on hinges and fold down to expose the C250’s insides should a service technician need to make any adjustments. No expense has been spared on the most visible evidence of the Classic approach to power amplification. The look exudes fineness. The front panel is a nearly two inch thick combination of extruded thick aluminum panels tied together both top and bottom with one inch slabs of hand finished aluminum. The entire assembly is then melded together to form the luscious curves you see. Parts quality is second to none. Low ESR capacitors, each bypassed by film and foil brypass capacitors, 1% resistors throughout, 40 hand selected high current bipolar output devices, custom wound and individually serialized 800va toroidal transformers, and the front panel meter is a custom manufactured replica of the great and classic Simpson volt meters of years ago. Nothing has been spared in the Classic 250. Inside, there are four main sections The design idea behind the Classic 250 is based on the marriage of four discrete and independent systems. The fact that each of these systems is completely independant both physically and electrically from the other is one of the keys to the Classic 250's sonic success. The four sections are: 
The Input Gain Stage As suggested in the HCA-2 power amplifier section, we have successfully created a “magic bullet” gain stage. A gain stage that is versatile enough to be used as the front end of the Hybrid Class A, or as the front end and gain stage of the Classic 250. This critical element is responsible for the way the amplifiers sound. By carefully tuning the audio parameters of the input gain stage we can tweak and play with the amplifier until it sounds absolutely musical. In the Classic 250, the input gain stage consists of two gain blocks: a zero feedback JFET input stage and a zero feedback bipolar stage. Both of these stages are fully differential. The input gain stage runs at extremely high voltages. In fact, the 200 volts used by this stage is one of the reasons why the C250 sounds so open and musical even during the loudest passage. All the C250’s 30 dB of gain is produced right here in the gain stage. This stage is completely independent  from the output current gain stage. The input stage is fed by its own regulated power supply that gets its power from a built in Power Plant (more on that later).Because the input gain stage has no interaction with the output stage, the Classic 250 sounds the same on virtually any loudspeaker load. The X1 output current stage is revolutionary It has taken nearly ten years of hard work and research to create the X1 output stage. Typically the output stage of a power amplifier is tied to the input stage and together they form a “team” to produce the power. Not so in the C250. This revolutionary and one-of-a-kind current stage is an absolutely separate and independent standalone current converter. It has its own power supply, its own feedback loop and is physically separated from anything else in the amplifier. Why this is important One of the classic challenges with creating a musically correct power amplifier design is that the load of the loudspeaker can and does influence the way the amplifier performs on a dynamic basis. This is because of the interaction between the voltage gain stage and the output current stage. Typically, they operate as a unit. The C250’s topology separates both electrically and physically these two entities. The topology allows the input gain stage to have zero  feedback, a critical parameter in its sonics qualities.In the same vein, the output gain stage has feedback. A controlled amount of feedback around this zero gain stage means that it has a high damping factor and is load invariant for different types of loudspeakers. Truly, this combination of independent stages results in the world’s first variable topology power amplifier designed specifically to maximize the musical experience. Output devices The C250 can handle loads as low as 2 Ohms and still breathe easily. To accomplish this we incorporated 20 high current output devices per channel. Each of the 40 output devices in the Classic 250 can handle 30 amps of power. The internal Power Plant The C250 introduces PS Audio’s first built in Power Plant.  Power Plants have revolutionized power within people’s homes forever. Now, it is available in a specially tuned version designed to enhance the performance and long term reliability of the C250.The 40 watt Power Plant inside the C250 powers the entire input gain stage and was hand tuned to maximize performance of the amp as a whole. After hours of listening tests we finally settled in one one a modified version of our favorite MultiWave patterns for the internal Power Plant: PS2. PS2 is the 'partial square wave' that we offer in all Power Plants with the MultiWave feature. This provides the cleanest and most open sound for the Classic 250 power amplifier. While the use of an AC regenerated waveform to power the insides of a power amp is not new (Mark Levinson company uses a 400 Hz sine wave inside their $18,000 to $30,000 power amps), using our patent pending MultiWave patterns is. PS2 is a pure 60 Hz sine wave and to that we add a small amount of pure 180 Hz. The effect this has is to flatten the top of the sine wave without losing any energy. This flattening of the sine wave if done propoerly, will provide a londer charging period for the gain stage voltage regulator inside the C250 amplifier, producing a rich and open soundfield unobtainable by an other method known.  We modified this waveform slightly to fit perfectly with the sonic requirements of the C250. This is truly unique and found only in PS Audio's new C250 power amplifier. Regardless of the power quality that enters the C250, what comes out of the built in Power Plant will be identical and help the C250 sound the same under most any power quality conditions. Why this was introduced We knew a full Power Plant capable of generating enough power for the entire amplifier would be as large as the amplifier itself. One of the goals of the C250 was to create a state of the art no compromise power amplifier no larger than the P600. To accomplish this feat it would be necessary to build all the gain into one low power stage so it could be coupled to a power regenerator. This works because the gain stage of an amplifier is the most sonically critical component in the chain. Once the input gain stage topology had been created, it was then a relatively easy task to produce a smaller version of the classic Power Plant series that could be built into the C250. The main power supply Obviously the purpose of a power amplifier is to generate power. Pure, clean and musical power that has no limitations. To accomplish this task we chose a dual mono approach.  Inside the C250 are two completely independent toroidal transformers, two power supplies, all connected with heavy 6 gauge wire to minimize any potential loss. Each of the two toroidal supplies is a monstrous 800 va transformer that is housed under its own chassis, isolated from the main body. These transformers feed a robust 80,000 mFd’s of energy storage. Voltage selection To further enhance the reliability and ease of operation of the Classic 250, we have designed a computerized circuit that will first measure the incoming AC voltage, then prepare the C250 for that voltage, and finally turn the C250 on without any further instructions from the owner. This means that the C250 will automatically operate safely in any country with no decisions being made on the part of our customers. Connecting the C250 to the outside world  The C250 is a completely balanced amplifier. It has both RCA single ended inputs as well as balanced XLR inputs available on both channels.Unlike many power amplifiers, the balanced inputs are true balanced meaning that there is no additional circuitry added to achieve balanced operation. The amp will display common mode rejection of over 80 dB when used in a balanced mode. This will provide superior noise rejection and improved performance with any balanced source. Each output of the C250 has two sets of high quality WBT binding posts available. One set can be used or both. We provide two separately wired sets of output binding posts to allow our customers to take advantage of bi-wiring situations where the upper and lower frequencies of your loudspeakers can be separated and separately cabled. Mono Operation Need more power than the Classic's 500 watts per channel into a 4 Ohm load? Then with the simple click of  the rear mounted switch, the Classic 250 turns into a virtual powerhouse when used as a mono amp. 1000 watts into an 8 Ohm loudspeaker and a whopping 1800 watts rms into a 4 Ohm load!Place one behind each loudspeaker, or create an entire 5 or 7 channel system with these babies. The possibilities are endless. The PS buss The Classic 250 is part of the growing PS Audio family of products. Each PS product that has a PS buss installed can communicate with any other similarly equipped PS product. The PS buss allows you to turn on and off the C250 from your PS preamplifier. It allows properly connected Crestron and CE buss networked systems to monitor the performance of the C250. To place the C250 on a network, you will need to have it connected to another piece of PS equipment that is properly interfaced to a CE network. The C250 can be assigned as one or as one of many power amps in the system. You can sequentially turn the unit on or off from a remote through a PS preamplifier or Power Director. The front panel  To emphasize the Classic look and feel of this state of the art amplifier, we added a beautiful analog power meter to the front sculptured panel. This custom made analog meter will display both power storage and show the user the effects of line voltage and power supply. The meter actually is monitoring both channels DC voltage. You can see what happens to this all important voltage when your power line goes up or down, and what happens when the Classic delivers its walloping bass notes to your speakers. The internal Power Plant will maintain a fully regulated voltage under any power line condition, but the output stage is directly tied to your power line. While the effects of poor quality power, or low voltage on the line is less critical to the output stage than the input stage, it is still worth noting what your home provides. The Classic 250 Our finest effort ever, the Classic 250 is finally a reality.  We couldn’t be prouder of its performance, reliability and looks.At $4,950 us retail the Classic 250 represents a true state of the art offering from a company you’ve trusted for over 30 years. Available as a stereo or mono amplifier, you can get one in the system first and use it's awesome power for the stereo. As time permits, you can at any time grab another C250 and quadruple the power to your speakers. This is one versatile system! Visit your local dealer or distributor, call us directly, or order one on line and experience it in your home against any other amplifier in the world regardless of cost or pedigree. There is no comparison. The Classic 250 stands alone as a true classic. Would you like to auditon one in the privacy of your own home, against whatever reference standard you might own? Call us at 720-406-8946 or simply click here and arrange for the audition on line. Or, contact one of our many dealers or distributors to audition the product today.
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