Mid frequency vocals: textbook level warm and natural, never getting tired of listening for a long time This is the core soul of this plan, preserving the iconic rich vocals of my carefully selected OPA2604 version. The singer's breath circulation, chest resonance, and lip and tooth details are gently and completely restored, without deliberate ear coloring or remote emptiness. The vocal structure is solid and full, and the emotional expression is delicate and long-lasting. Enjoy the charm of analog flavor that modern operational amplifiers cannot match. High frequency performance: smooth and transparent, with full overtones and air sensation Through the use of additional components, the common problem of OPA2604's native high-frequency dimming has been precisely cured, while completely retaining the auditory endurance of the warm sound operational amplifier. The high frequency brought by Panasonic film capacitors is a natural extension of brightness and overtones. Color: Purple Material: PCB Package Contents: 1*OPA2604 Operational Amplifier 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.