Description
Yamaha C-2a Preamplifier 120v clean and quiet in working condition From JAPANDescription Type Control amplifierInput Sensitivity/Impedance Phono1 MM:2.5mV/47k?, 68k?, 100k?Phono1 MC:100?V/50?Phono2 MM:2.5mV/47k?Aux, Tuner, Tape PB1/2:150mV/47k?Cartridge load 100k?, 68k?, 47k?, 100?Maximum allowable input Phono1 MC:10mV or more (20kHz, 0.03%)Phono1/2 MM: 350mV or more (1kHz, 0.01%)Aux, Tuner, Tape PB1/2: 30V or more (Volume -34dB)Rated Output/Impedance/Maximum Output Pre out1/2:2V/250?/15V min.Rec out1/2:150mV/100?/20V min.Frequency Response Phono1/2 MM:20Hz to 20kHz 0±0.2dB(RIAA)Phono1 MC:20Hz to 20kHz 0±0.3dB(RIAA)Aux, Tuner, Tape PB1/2: 10Hz to 100kHz +0 -0.2dBTotal harmonic distortion(20Hz to 20kHz) Phono1/2 MM:0.003% or lessPhono1 MC: 0.01% or lessAux, Tuner, Tape PB1/2: 0.003% max.Harmonic distortion (20Hz to 20kHz)Sum of 2nd to 10th order at HP-IB) Phono MM?Rec out(1.5V):0.0007% max.Aux, Tuner, Tape1/2?Pre out: 0.0007% or lessModulation distortion ratio Aux, Tuner, Tape PB1/2: 0.003% or less (10V output)SN ratio (IHF-A network) Phono1/2 MM:92dB or betterPhono1 MC:78dB min.Aux, Tuner, Tape PB1/2: 103dB or betterResidual noise: 0.03?V or lessChannel Separation(1kHz, Volume max) Phono1/2 MM: 90dB min.Phono1 MC: 78dB min.Aux, Tuner, Tape PB1/2: 90dB or betterFunction Separation(1kHz, Volume max) Phono1/2 MM?Tuner: 90dB min.Tuner?Phono1/2 MM:95dB min.Aux?Tuner: 90dB min.Tone Control CharacteristicsTurnover frequency Bass:350HzTreble: 3.5kHzMaximum variable range Bass: ±10dB(20Hz)Treble: ±10dB(50kHz)Subsonic filter 15Hz, 12dB/octAudio muting: -20dBSemiconductors used FETs: 5Semiconductors: 101Zener diodes: 10Diodes: 32AC outlet switched: 400Wmaxunswitched: 400WmaxPower supply AC100V, 50Hz/60HzPower consumption 36WDimensions Width 435 x Height 72 x Depth 320mmWeight 7.9kg As an improved version of the C-2, this control amplifier uses newly developed parts including low-noise high-gm Dual FETs. The basic circuit configuration consists of a low-noise head amplifier for MC cartridges, a low-noise equalizer amplifier assembled with a current noise reduction circuit, and a high-precision tone control amplifier. All amplifier circuits are balanced all-stage push-pull to minimize distortion in principle, and are also DC amplifiers.The main improvements from the C-2 to the C-2a are characteristic improvements and additional functions. First, all characteristics such as distortion ratio, signal-to-noise ratio, frequency response, and transient response have been greatly improved. Then, the Phono Selector and Rec out Selector have been added, and a continuously variable tone control has been adopted. In addition, parts that have been carefully selected for their sound quality have been fully employed. The first stage of the equalizer amplifier uses a newly developed low noise high gm Dual FET (2SK101). The 2SK101 is an N-channel silicon junction FET with excellent low noise characteristics, especially low 1/f noise, high gm of 120 mho (Typ.), and matching electrical and thermal pair characteristics of the pair FETs.The circuit configuration consists of a differential circuit with low-noise high-gm Dual FETs and a new cascode bootstrap circuit that is effective in improving DC drift, which is a problem in DC amplifiers, preventing distortion rate degradation due to an increase in signal source impedance when the cartridge is mounted, improving frequency response, and reducing current noise. In addition, an automatic balanced active load, which is effective in further reducing distortion rate, is also employed. The pre-drive stage of the equalizer amplifier section consists of a current mirror differential push-pull circuit. The output stage is a two-stage emitter follower complementary push-pull circuit using transistors with high fT and sufficient collector loss.The use of a current mirror circuit minimizes distortion, and the two-stage emitter-follower complementary push-pull circuit provides a low output impedance of 100 ? and sufficient output voltage with low distortion. The RIAA element, which determines the accuracy of the equalizer, uses a high-precision large-capacity metal film resistor and a newly developed high-precision polypropylene film temperature compensated capacitor to achieve high accuracy. A current noise reduction circuit is used to reduce current noise generated from the load resistance of the cartridge.In this circuit, the value of the load resistance is set to a large value to reduce current noise. In order to prevent the characteristics from being adversely affected by a large load resistance, a resistance several times higher is used, and the current noise reduction circuit provides the desired apparent load resistance.This results in a load resistance that is a fraction of the resistor used, which lowers the current density of the input conversion noise and provides an equivalently low noise load resistance. The MC head amp is a DC amp with a new cascode complementary push-pull circuit consisting of four NPN/PNP low-noise transistors with low rbb (base resistance) and large hfe each connected in parallel to reduce voltage-related noise, and one additional transistor connected in cascode. The DC amplifier configuration consists of four NPN/PNP transistors connected in parallel. The complementary push-pull circuit is composed of low-noise transistors connected in parallel, resulting in excellent low noise and low distortion characteristics. The Phono 1 circuit of the C-2a can be configured with load resistance and load capacitance to match the cartridge used. The load resistance can be set according to the Phon Shipping FedEx?or DHLInternational Buyers - Please Note:Import duties, taxes, and charges are not included in the item price or shipping cost. These charges are the buyers responsibility. Please check with your countrys customs office to determine what these additional costs will be prior to bidding or buying. Thank you for your understanding.
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