Power supply voltage: 110 ~ 220V AC
Applicable headphone resistance range: 16-120 Euro
Frequency range: 12Hz-15kHz (-1dB)
Distortion: 0.001%@1kHz
Output noise level: -96dB
Output impedance: less than 1 ohm;
Rated output power: 150mW/16Ω; 290mW/32Ω; 350mW/64Ω;
Input sensitivity: 1000mV rms(-7dB) for rated output;
Gain: 1 (low gain); 4 (high gain)
Volume: 160*116*48mm (length, width, height),
Weight: 950g
There is a special loose empathy. Its circuit has no voltage gain, but only reduces the output impedance, and uses a large-impedance negative feedback circuit to offset the back-EMF of low-impedance headphones as much as possible. This design brings extremely high signal-to-noise ratio and control power. The sense of listening is very delicate and loose. When I pair Goethe and Philips low-impedance high-sensitivity headphones, they do have their own characteristics. Do you like it? I hope users try it by themselves. This amp is used with our L1852DAC and L4490DAC. In the small compilation works such as vocals and chamber music, there will be a very unique sense of air and soft high frequency.
Finally, when I borrowed a friend’s new version of the original RA1 amp, I was surprised to find that there was an amplification gain. So at the end of the design, I made the following decision:
1. The use of AC power supply saves the trouble of changing the battery and avoids the danger of burning the headset after the battery is depleted.
2. Add gain control. When the two red switches are on, the gain is about 1; when off, the gain is the same as the new version, about 4.
3. Add the earphone protection circuit, although the original version does not, but for safety, this design is still retained.
Package Accessories list ：
L.RA1 AC is a low-impedance high-sensitivity amp headphone amplifier