<div class="document"> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">注：* 为必填项</p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;"><strong><span style="color:#0093e6;">请在报名阶段填写 ↓</span></strong></p> <h3 class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">* 1、项目功能介绍</h3> <hr class="horizontal-splitline normal-bold-2"><ul><li class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;"><span style="color:#000000;font-size:14px;">一<strong>.功能描述</strong></span></li> <li><span style="color:#000000;"><span style="font-size:14px;">AUX音频输入+蓝牙输入二合一20Wx2输出模拟功放</span></span></li> <li class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;text-align:left;">6N2为前级缓冲放大+LM1875x2后级</li> <li class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;text-align:left;">电子管具有输入动态范围大，转换速度快等优点；LM1875也是大家的老朋友了，具有着超低的失真率，同时有着不错的输出功率，还有着过载和过热等保护。作为本次电路的核心</li> <li class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;text-align:left;">加入蓝牙多样化输入方式，在传输距离和效率上都不错。</li> <li class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;text-align:left;"><strong>参数描述</strong></li> <li class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;text-align:left;">1.电源部分，主供电用一个3P的接线座相连。2颗输入保险，防止过载’短路。</li> <li>主供电范围：AC12-18V</li> <li><br><img src="//image.lceda.cn/pullimage/yetdxmTm6uFDtMpDYhOU4TnyjJRvIUDzuXdQGdWr.png" alt="" width="255" height="317"></li> <li>前级灯丝和蓝牙板供电。</li> <li>采用DC-DC方案，使用LM2596降压到+6.3v为6N2灯丝供电</li> <li><img src="//image.lceda.cn/pullimage/pOUqfgF9ljdTEowi0ukDjPBCdexWGrHnf7I9N8cy.png" alt="" width="441" height="382"></li> <li>蓝牙板供电，取灯丝供电经过LC滤波后经D4压降后为蓝牙板供电。</li> <li><img src="//image.lceda.cn/pullimage/fJU8MAWlknVOz3tiW9zCR4oSA0GCF4U7O8yxanIx.png" alt="" width="331" height="250"></li> <li>前级放大为一颗曙光的6N2。音色上有一定改变，听感上也有一定的改善。电路没有加装任何的混音和润色，基本上原汁原味。</li> <li><img src="//image.lceda.cn/pullimage/FeAEq8EIaVEPDQAOJJVktV7XTSAMxDsNnUSMAlMq.png" alt="" width="370" height="288"></li> <li><img src="//image.lceda.cn/pullimage/Ckjbl3HSDIwFngT0YSkkqPD7iVJj2XIXwah0lrbU.jpeg" alt="" width="368" height="491"></li> <li>LM1875外围电路基本按照官方电路图设计</li> <li><img src="//image.lceda.cn/pullimage/S8As2eFf7lqqmcvvjr8t98kiclU9SD8g2Atq8idR.png" alt="" width="466" height="361"></li> <li>M18蓝牙版是淘宝购买的现成模块，电源供电处加入LC滤波，四个控制按键。</li> <li><img src="//image.lceda.cn/pullimage/7sgXH9qOsmuM9BDClnEfC9KnAKiq6CNTqGSDSJPE.png" alt="" width="333" height="316"></li> <li><strong>接口描述</strong></li> <li>主供电接口为JL301接线端子，电源开关加在变压器输入端。</li> <li>音频输入方式，有线输入和无线输入。手动切换方式，开启或关闭蓝牙SW1</li> <li>2.0双通道，依然使用两个2P接线柱，连接到两个全频喇叭，建议阻抗4-8欧，功率20瓦x2</li> <li><strong>功能测试</strong></li> <li>期盼已久的快递和PCB终于到了，焊接好了后直接翻到沟里去了，不能正常工作，经过一番分析。发现原理图的，VEE和GND画短路了</li> <li>贴图说明，原理图中已更正。</li> <li><img src="//image.lceda.cn/pullimage/fZJksebbYNU6o96KiZrJK69vkZ9SsmRPQk73ohzu.png" alt="" width="358" height="382"></li> <li>问题二，6N2小九角的PCB库封装错误(脚位错误)</li> <li>贴图说明，库封装已更新。PCB待更新。</li> <li><img src="//image.lceda.cn/pullimage/tcF0f0Li5ScITNscFrHYZGRF97F7aK9HzFCODWkq.png" alt=""></li> <li>问题三，LM1875自激振荡(怀疑是把所有的GND都覆在一起的原因)这一版我用了一个按键SW7(兼前级使用/取消按键)去直接上拉消除振荡，但这样喇叭会有直流损耗</li> <li>亲测发现，上拉以后听不到任何的自噪声也不影响播放音乐，一切正常</li> <li>欢迎各位评论区留言想想办法，PCB设计中降低或消除自激</li> <li><strong>成品展示</strong></li> <li><img src="//image.lceda.cn/pullimage/TvMXHSRsCLzw1ausRUEjuVa2cLpF2UWfMTPtjLvq.jpeg" alt="" width="1200" height="1080"></li> <li><img src="//image.lceda.cn/pullimage/u7eOq2huvYIHCIl38me10X2GTW1pzbqkJPrCAHnd.jpeg" alt="" width="1200" height="1080"></li> <li>两个1875的散热，一块CPU的散热器足够了，图上使用的喇叭是八欧姆15瓦的。</li> <li><strong><span style="color:#e03e2d;">注意:</span></strong><span style="color:#e03e2d;">PCB没有更新，前级暂时还不能使用1875自激未完善解决</span>。</li> <li><span style="color:#e03e2d;">本次是纯后级测试</span>。</li> <li>欢迎各位朋友评论区指正错误，先行道谢了。</li> </ul><p style="text-align:left;"> </p> <h3 class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">*2、项目属性</h3> <hr class="horizontal-splitline normal-bold-2"><p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;"><span style="color:#95a5a6;font-size:14px;">首次公开</span></p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;"><span style="color:#95a5a6;font-size:14px;">试着把电子管和晶体管相结合起来</span></p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;"><span style="color:#95a5a6;font-size:14px;">体验电子管+经典LM1875</span></p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;"><span style="color:#95a5a6;font-size:14px;">看能不能擦出不一样的火花</span></p> <h3 class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">* 3、开源协议</h3> <hr class="horizontal-splitline normal-bold-2"><p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">1<span style="color:#000000;">.<span style="font-size:14px;">拥抱开源，分享，快乐无限！</span></span></p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">2.开源协议GPL3.0</p> <h3 class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">*4、硬件部分</h3> <h3 class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">*5、软件部分</h3> <h3 class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">*6、BOM清单</h3> <h3 class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">*7、大赛LOGO验证</h3> <hr class="horizontal-splitline normal-bold-2"><p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;"><img src="//image.lceda.cn/pullimage/fA8POuvv8YyznqNsyv9MTJpQpevkjK8dBD7gpJKh.jpeg" alt="" width="557" height="418"></p> <h3 class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">* 8、演示您的项目并录制成视频上传</h3> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;"><span style="font-size:14px;">更多详情：<a href="/posts/06c94d90c2c447dfbd9ed7339ff4a5b1" target="_blank">https://diy.szlcsc.com/posts/06c94d90c2c447dfbd9ed7339ff4a5b1</a></span></p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;"> </p> </div>