HiFi B21 Op-amp Stereo Preamplifier Board Audio Preamp Kit

Description: Details：On the basis of the popular B2, the B21 preamplifier has made significant changes to the sound, making it closer to the reference level. In addition to atmospheric balance, high dynamics, and no change in listening endurance, it also strives to accurately reproduce the sound and soundstage, allowing the various textures, positioning, and soundstages of vocals and instruments to be reproduced as much as possible.This preamp adopts a 4-layer PCB design to minimize interference and noise as much as possible to achieve a dark background quietness.PCB size：155x145mmHeight：35mmWork voltage：AC14V-0-AC14V To AC18V-0-AC18V above 20WPH resistance and BC capacitanceOp-amp model：Use 4pcs single operational amplifier （opa1611，OPA627AU，JRC5534DD，MUSES03 etc），default price not included Op-amp ！Debugging instructions:Before testing, ensure that all components are installed correctly and there are no virtual soldering or short circuits.1. Do not install all operational amplifiers before powering on2. Connect dual 14V-18V AC, adjust VR1 ，set +V to+15V, adjust VR2 ,set -V to-15V3. Install operational amplifiers U1 and U2, adjust VR3, and measure TP1 to be close to 0V (+/-10mV),Adjust VR4 and measure TP2 to be close to 0V (+/-10mV), all measured to ground4. Install operational amplifiers U3 and U4, You can test the soundNote：Diy Kit 1： as the picture show ，not included capacitance ，potentiometer，op-amp and RCA ！all parts need buyer to solder it ！Diy Kit 2： as the picture show ，not included potentiometer，op-amp and RCA ！all parts need buyer to solder it ！Assembled Board：as the picture show ，not included potentiometer，op-amp and RCA ！have solder it well and test ！

Price: 25 USD

Location: 广州市

End Time: 2025-01-16T08:56:11.000Z

Shipping Cost: 5 USD