The dual op amps are made of fully discrete components, 14 pairs of clastic triodes, 4 pairs of triodes, and 2 pairs of power amplifiers for current amplification. The upper and lower two-layer board components are the same as the base tree, which can achieve better matching. Class A output (CLASS A OUTPUT) 15MA, the maximum output is 65MA.Because of this, the overall timbre sound field is wide and full, the scene is large, the levels are clear, the mid-range is bright and clear, the density is large, the low-frequency dive deep and flexible. High-frequency performance: the sound is relaxing and aura Intermediate frequency performance: The vocal performance is relatively full, with good resolution and image power, the sound is stretched, the vocal performance details are natural, the levels are clear, and the sound is clean. Low frequency performance: Low frequency is strong and powerful.Note: The overall sound line and sound style are generally similar, there be differences in different devices, please be careful when , thank you. Product parameters: Supply voltage: ± 6V to ± 18V CLASS A output current 15mA Maximum output current 65mA Fully discrete components + N: 0.0003% (1KHZ) - 112dB Low noise: 3.6nV / 7Hz at 10KHZ Low open loop gain: ~ 25dB NOTE: Depending on the batch, the appearance of the electronic components on the board may be different from the picture, but the functions are the same and do not affect use. Material: PCB+electronic components colour: Green Package Contents: 4 x OPAMP Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.