这台机准备彻底的打摩！请大家都给出点主意吧

HQ

<><br>机机是土八路兄的[em11]<br><br><br>

这台机准备彻底的打摩！请大家都给出点主意

</P>
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这台机准备彻底的打摩！请大家都给出点主意

</P>
<>

这台机准备彻底的打摩！请大家都给出点主意

</P>
<>

这台机准备彻底的打摩！请大家都给出点主意

</P>
<>

这台机准备彻底的打摩！请大家都给出点主意

</P>
<>

这台机准备彻底的打摩！请大家都给出点主意

</P>
<>

这台机准备彻底的打摩！请大家都给出点主意

</P>

<>

这台机准备彻底的打摩！请大家都给出点主意

</P>
<><br><br><br><br><br>[em11][em11][em11][em11][em11]<img src="attachments/dvbbs/2005-4/200549205040251.jpg" border="0" onload="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onmouseover="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.style.cursor=\'hand\'; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onclick="if(!this.resized) {return true;} else {window.open(\'attachments/dvbbs/2005-4/200549205040251.jpg\');}" onmousewheel="return imgzoom(this);" alt="" /><img src="attachments/dvbbs/2005-4/20054920517658.jpg" border="0" onload="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onmouseover="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.style.cursor=\'hand\'; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onclick="if(!this.resized) {return true;} else {window.open(\'attachments/dvbbs/2005-4/20054920517658.jpg\');}" onmousewheel="return imgzoom(this);" alt="" /><img src="attachments/dvbbs/2005-4/200549205119695.jpg" border="0" onload="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onmouseover="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.style.cursor=\'hand\'; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onclick="if(!this.resized) {return true;} else {window.open(\'attachments/dvbbs/2005-4/200549205119695.jpg\');}" onmousewheel="return imgzoom(this);" alt="" />[em11][em11][em11]<br>[em11]<br></P><br>

饿狼

以下是引用骑手在2005-4-10 19:50:00的发言：
他告诉过我，说数字伺服部分有一颗运放一定要换，具体换什么可以自己试验决定。

骑手

他告诉过我，说数字伺服部分有一颗运放一定要换，具体换什么可以自己试验决定。

37度

以下是引用小鬼头在2005-4-10 18:50:00的发言：
CWW11兄，你那个模块式分立件电源能否公开？贴上来，我有兴趣。。。。[em09]

<img src="attachments/dvbbs/2005-4/2005410184947565.jpg" border="0" onload="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onmouseover="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.style.cursor=\'hand\'; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onclick="if(!this.resized) {return true;} else {window.open(\'attachments/dvbbs/2005-4/2005410184947565.jpg\');}" onmousewheel="return imgzoom(this);" alt="" />

[em09][em09][em11]

小鬼头

http://www.dhaen.org.uk/vdocs/saa7350_bw.pdf

小鬼头

CWW11兄，你那个模块式分立件电源能否公开？贴上来，我有兴趣。。。。[em09]

<img src="attachments/dvbbs/2005-4/2005410184947565.jpg" border="0" onload="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onmouseover="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.style.cursor=\'hand\'; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onclick="if(!this.resized) {return true;} else {window.open(\'attachments/dvbbs/2005-4/2005410184947565.jpg\');}" onmousewheel="return imgzoom(this);" alt="" />

小鬼头

来自下面这个帖子。。。前面的三端稳压块是2。5V的，据作者说噪声颇大，通过RC来削除。。。发帖者JOHNW还设计过英国剑桥的D700解码器、CD4一体机

http://www.diyaudio.com/forums/showthread.php?s=&threadid=25213&perpage=10&highlight=vref+5534&pagenumber=3

JohnW []
diyAudio Member

Online
Registered: Jan 2004
Location: HK / CZ / FR


  Post #23  
I Agree with Peter, you can always hear the Sonic effects of Caps ?great care has to be taken to reduce their effect in the circuit.

The Vref pin on an ADC/DAC is one of the most critical nodes in a circuit, and is often over looked. Internally, this pin is normally used to supply charge to a Switch capacitor network (in a 1 Bit or Low Bit DAC). The charge is drawn at the internal switching rate ?but with an Audio modulation component. Therefore, this Node needs to be well de-coupled at both the Audio Band and 揜F?frequencies.

If you where to perform an Impendence plot of any capacitor, you will see a wildly varying curve, with the De-Coupling properties of the capacitor rapidly reducing at LF. This increasing impendence at LF has a large impact on Bass quality ?resulting in ? Bit or Low Bit?DAC抯 sounding 搇ight?in the Bass.

Most Vref pins are at half VCC typically 2.5V. The internal Bias generator can only supply a limited current, so there抯 no point in hanging large De-coupling caps on them ?it will take forever to charge these up ?and you will still be left with the Caps varying impendence which will impact its 揻oot print?on the sound.

The best approach is to add external Very Low Noise and ultra low impedance Vref Generator. Below is a circuit I often use. Pls. note, it抯 for designs where Vref is 2.5V. Due to the 揌igh?impedance of the internal Vref (VBias) Gen, they don抰 normally mind the addition of the external Gen. Nevertheless; it抯 prudent to match the output voltage of the External Generator, as close to the output voltage of the internal Gen as possible.

Due to the Feedback of the OP-AMP, the impedance of the Generator appears almost 揻lat?within the Audio band (in fact, the output impedance is much LOWER at LF) ?thereby limiting the sonic 揻ootprint?of the VRef Capacitor used. Its important to realise that RF decoupling is still required, and the OP-Amp will offer very little correction - due to its limited gain Bandwidth at RF. The RF quality of the 100nF ceramic is critical, try placing it directly across the DAC Vref Pin and Ground ?and the electrolytic C5 should be a Low ESR such as an OS-Con or Tant. The quality will now be less critical, due the active correction of the OP-AMP.

Note, the feedback is taken FROM the DAC Vref pin; this removes the effect of PCB wiring and any noise. The limitation at LF is now due to the DAC抯 package bonding impendence.

The FB connection should be as short as possible back to the Op-Amp.

JohnW has attached this image:
Click the thumbnail to see the original image.

DANIELYANG

7879的稳压用两对并联，直接并上去就行吗，有什么讲究没有？

stswx

此机最大的问题是电源严重不足，我给加了三个变压器（原想一个大的多个绕组，但看到许多解码器用上3个小变压器才想这样更能减少干扰，还更容易安装）。一个双18v稳15给模拟的，一个双15v稳12v给控制电路的，一个两组5v给数字电路的。原变压器只供显示用。为了安全和减少空间，全部用7879的稳压，控制和模拟电路用两对并联，数字分两路供电也用两个7805并联（具体在哪分电源太久忘了，要重新看到才知）。模拟和控制电源电容用摩罗利25v10000u并上西电2200u最好，稳压后用JENSEN的，不要再加什么0.1u的东西，那更不好。数字电源用RIFA25v40000u，稳压后用TCC25v1000u。另外原电路板上留有很多退偶的电容位没装，在那装上TCC的就行。再把电源线换了，安个插座，方便换线。把5532拆了换个镀金座，方便换IC，把输出的那个4.7u电解换成蓝精灵的或JENSEN的。最后用胶把所有电容都胶上，减少震动。
通过以上更改，好像换了不机，当然也用了600多，都是拆旧的元件，但那音乐味，那高低音的通透感都让你很过瘾。最后把四只脚也换了。

小鬼头

以下是引用wongkm33在2005-4-10 12:38:00的发言：
这位作者在鬼老网页非常活跃，小鬼头版主最熟悉，并大赞他的文章非常有水准

对呀。。。。大概是93年的杂志，杂志里称原文寄自英国。。。。。作者署名就是K Y WANG

而现在的DIYAUDIO坛上，K Y WANG经常显示他的见多只广、功底扎实。。。。确是一猛人
[em09][em12]

37度

摩机的事就交由土八路操刀！他忙得过来吗？[em02]  馊主意还不少。

[em02]

吻子

[em09]
电源摸摸...才爽

cww11

以下是引用文招在2005-4-10 16:32:00的发言：
那一块硬币我是直接压在碟压红色的地方<img src="attachments/dvbbs/2005-4/2005410163222917.jpg" border="0" onload="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onmouseover="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.style.cursor=\'hand\'; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onclick="if(!this.resized) {return true;} else {window.open(\'attachments/dvbbs/2005-4/2005410163222917.jpg\');}" onmousewheel="return imgzoom(this);" alt="" />

我试一下先！！！！

37度

一块硬币放上去不更搪吗？[em11]

文招

那一块硬币我是直接压在碟压红色的地方<img src="attachments/dvbbs/2005-4/2005410163222917.jpg" border="0" onload="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onmouseover="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.style.cursor=\'hand\'; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onclick="if(!this.resized) {return true;} else {window.open(\'attachments/dvbbs/2005-4/2005410163222917.jpg\');}" onmousewheel="return imgzoom(this);" alt="" />

cww11

以下是引用文招在2005-4-10 11:31:00的发言：
1<I></I> 接在原78,79的输出脚(当然要拆开78,79)
2<I></I> 接在原78,79的输入脚(当然要断开原模拟井流)
3<I></I> 直接接在5532的4,8脚上
还是有什么方法?
[em03][em03][em03][em03][em03]

模拟部分我是用分立件的
弄成模块形式，效果特好！！！

cww11

弄成模块形式，效果特好！！！

墨西哥跳豆

前级器材再好，没有后级器材放靓音还是空谈！
最少要等你的后级器材的放音水平高于CD机的音质一个档次，磨CD机才切实可行！

文招

否则一模一样的按他的改[em11][em11][em11]

wongkm33

这位作者在鬼老网页非常活跃，小鬼头版主最熟悉，并大赞他的文章非常有水准<img src="attachments/dvbbs/2005-4/2005410123444771.jpg" border="0" onload="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onmouseover="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.style.cursor=\'hand\'; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onclick="if(!this.resized) {return true;} else {window.open(\'attachments/dvbbs/2005-4/2005410123444771.jpg\');}" onmousewheel="return imgzoom(this);" alt="" /><img src="attachments/dvbbs/2005-4/200541012359120.jpg" border="0" onload="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onmouseover="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.style.cursor=\'hand\'; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onclick="if(!this.resized) {return true;} else {window.open(\'attachments/dvbbs/2005-4/200541012359120.jpg\');}" onmousewheel="return imgzoom(this);" alt="" /><img src="attachments/dvbbs/2005-4/2005410123537122.jpg" border="0" onload="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onmouseover="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.style.cursor=\'hand\'; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onclick="if(!this.resized) {return true;} else {window.open(\'attachments/dvbbs/2005-4/2005410123537122.jpg\');}" onmousewheel="return imgzoom(this);" alt="" /><img src="attachments/dvbbs/2005-4/20054101236695.jpg" border="0" onload="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onmouseover="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.style.cursor=\'hand\'; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onclick="if(!this.resized) {return true;} else {window.open(\'attachments/dvbbs/2005-4/20054101236695.jpg\');}" onmousewheel="return imgzoom(this);" alt="" /><img src="attachments/dvbbs/2005-4/2005410123628530.jpg" border="0" onload="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onmouseover="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.style.cursor=\'hand\'; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onclick="if(!this.resized) {return true;} else {window.open(\'attachments/dvbbs/2005-4/2005410123628530.jpg\');}" onmousewheel="return imgzoom(this);" alt="" /><img src="attachments/dvbbs/2005-4/200541012371363.jpg" border="0" onload="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onmouseover="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.style.cursor=\'hand\'; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onclick="if(!this.resized) {return true;} else {window.open(\'attachments/dvbbs/2005-4/200541012371363.jpg\');}" onmousewheel="return imgzoom(this);" alt="" /><img src="attachments/dvbbs/2005-4/2005410123727160.jpg" border="0" onload="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onmouseover="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.style.cursor=\'hand\'; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onclick="if(!this.resized) {return true;} else {window.open(\'attachments/dvbbs/2005-4/2005410123727160.jpg\');}" onmousewheel="return imgzoom(this);" alt="" /><img src="attachments/dvbbs/2005-4/2005410123746829.jpg" border="0" onload="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onmouseover="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.style.cursor=\'hand\'; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onclick="if(!this.resized) {return true;} else {window.open(\'attachments/dvbbs/2005-4/2005410123746829.jpg\');}" onmousewheel="return imgzoom(this);" alt="" /><img src="attachments/dvbbs/2005-4/200541012381373.jpg" border="0" onload="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onmouseover="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.style.cursor=\'hand\'; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onclick="if(!this.resized) {return true;} else {window.open(\'attachments/dvbbs/2005-4/200541012381373.jpg\');}" onmousewheel="return imgzoom(this);" alt="" />