First Watt J2 Power Amplifier
The J2 is a stereo power amplifier rated at 25 watts per channel. It has a two-stage circuit that operates in pure single-ended Class A mode, with signal JFET devices forming the input stage and power JFET devices for the output stage.
JFET transistors have long been recognized as having the highest audio quality of any transistor; the input devices of the J2 are known through the industry as the standard for low noise and linearity, and are found on the inputs of the finest phono stages, line level preamplifiers, and power amplifiers.
But for over 30 years robust power JFETs have not been widely available since the short-lived efforts of Sony and Yamaha. In the last few months, advances in Silicon Carbide (SiC) technology have resulted in new power JFET transistors with high voltage, current, and power capabilities ‚¬œ as high as 1200 volts, 30 amps, and 273 watts.
Created by SemiSouth Corporation of Mississippi, these robust new JFETs are designed for very fast high power switching in solar power and electric car applications. However, they also have a very low distortion characteristic that makes them superb for use in linear amplifiers. In apples-to-apples comparisons with comparable MOSFET type power transistors, they can achieve 10 to 20 dB improvements in distortion performance.
For over 10 years First Watt has been pushing the design envelope with simple high performance Class A amplifier circuits, and when a better transistor like this comes along, it can mean getting the same distortion performance with a lot less feedback, or lower distortion with the same amount of feedback. The J2 does amplifier does both,and that helps make it a better sounding amplifier than the best of its predecessors.
Measured at 120 V AC and an 8 ohm load:
Distortion @ 1 watt 025% @ 1 KHz Input Impedance 100 Kohm Balanced input CMRR -60 dB @ 1 Khz Gain 20 dB Input Sensitivity 280 mV = 1 watt, 1.4 V = rated power Damping Factor 20 Output power 8 ohms 30 watts @ 1% THD, 1KHz Output Power 4 ohms 15 watts @ 1% THD, 1 KHz Frequency response - 1 dB @ 4 Hz, 100 KHz Noise 100 uV unweighted, 20-20 KHz Power consumption 200 watts Fuse 3AG slow blow type - 2.5 Amp for 120VAC 1.25 Amp for 240 VAC
All eligible company warranty and service support is being provided on First Watt J2 Power Amplifier