制作“纯真之源——6550单端”遇到问题请烧友指教

试水

<p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">&nbsp;&nbsp;&nbsp; 前级</span><span lang="EN-US"><font face="Times New Roman">6H8</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">部分是分开左右声道滤波，两声道布线完全一样。现遇到如下问题：</span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt 18pt; TEXT-INDENT: -18pt; mso-list: l0 level1 lfo1; tab-stops: list 18.0pt;"><span lang="EN-US" style="mso-fareast-font-family: &quot;Times New Roman&quot;;"><span style="mso-list: Ignore;"><font face="Times New Roman">1、<span style="FONT: 7pt &quot;Times New Roman&quot;;">&nbsp; </span></font></span></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">右声道有交流声，一米远还听到。左声道交流声很大，三米远还听到。</span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt 36pt; TEXT-INDENT: -36pt; mso-list: l1 level1 lfo2; tab-stops: list 36.0pt;"><span lang="EN-US" style="mso-bidi-font-family: 宋体;"><span style="mso-list: Ignore;"><font face="Times New Roman">（1）<span style="FONT: 7pt &quot;Times New Roman&quot;;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></font></span></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">试加大滤波电容和各级退偶电没有见效。不是滤波问题。</span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt 36pt; TEXT-INDENT: -36pt; mso-list: l1 level1 lfo2; tab-stops: list 36.0pt;"><span lang="EN-US" style="mso-bidi-font-family: 宋体;"><span style="mso-list: Ignore;"><font face="Times New Roman">（2）<span style="FONT: 7pt &quot;Times New Roman&quot;;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></font></span></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">试增大两个反馈电容没见效。</span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt 36pt; TEXT-INDENT: -36pt; mso-list: l1 level1 lfo2; tab-stops: list 36.0pt;"><span lang="EN-US" style="mso-bidi-font-family: 宋体;"><span style="mso-list: Ignore;"><font face="Times New Roman">（3）<span style="FONT: 7pt &quot;Times New Roman&quot;;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></font></span></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">断开第一级输出电容交流声消失。试拆除输入电位器在第一级栅级和地间接入</span><span lang="EN-US"><font face="Times New Roman">6.8K</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">电阻，交流声于旧不见有效。不是电位器接地不当引起。</span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt 36pt; TEXT-INDENT: -36pt; mso-list: l1 level1 lfo2; tab-stops: list 36.0pt;"><span lang="EN-US" style="mso-bidi-font-family: 宋体;"><span style="mso-list: Ignore;"><font face="Times New Roman">（4）<span style="FONT: 7pt &quot;Times New Roman&quot;;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></font></span></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">手上有新购的前苏联</span><span lang="EN-US"><font face="Times New Roman">OTK 6H8C</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">，左声道换过三个不见效，但换一个南京</span><span lang="EN-US"><font face="Times New Roman">58</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">年产</span><span lang="EN-US"><font face="Times New Roman">6H8C</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-fo

Julien

<p>接地：机壳输入R6R8——C5——R7R16——C6——R10R12C4——C8。前级6.3V交流中心抽头接在C9负端。输出牛地接在R8负。</p>

kamei

问题来了

Julien

ok,解决就好

试水

<p>J版！正如你所估计一样，是管子灯丝耐压不够引起交流声。另分压一个直流45V电压加在灯丝上把问题解决了。耳朵喇叭离20CM听不到交流声。多谢J版指教。</p><p></p>

Julien

R8

试水

<div class="quote"><b>以下是引用<i>Julien</i>在2007-3-20 19:22:00的发言：</b><br/><p>接地：机壳输入R6R8——C5——R7R16——C6——R10R12C4——C8。前级6.3V交流中心抽头接在C9负端。输出牛地接在R8负。</p></div><p>输出牛地接在R8负。还是C8负端？</p>

xhzxd

原帖由 试水 于 2007-3-21 20:53 发表
J版！正如你所估计一样，是管子灯丝耐压不够引起交流声。另分压一个直流45V电压加在灯丝上把问题解决了。耳朵喇叭离20CM听不到交流声。多谢J版指教。

另分压一个直流45V电压加在灯丝上把问题解决了。请楼主详细说明一下是怎么弄的？谢谢！

kenny

如题。

试水

从高压串两个电阻，我用220K和6.8K串，得一个12V左右的对地电压，再在6.8K电阻上并一个330U/25V电容。把原来接地灯丝电压不接地改接到这个12V电压点。