有没有 49811 芯片的？现在老外都在用这个芯片了。

tel5169553 · 发表于 2010-5-11 10:58

有没有 49811 芯片的？现在老外都在用这个芯片了。
比49810 更好。价格还稍微低点。
据说 49810 为了扩流输出，用了a/b 类。而49811 没有，而且参考了硅谷一位 ic 设计大牛的意见，还有一点别的调整。

wayne · 发表于 2010-5-11 11:08

LME49811芯片是LM4702立体声驱动器的单声道版本，其特点是可以驱动放大器输出级的达林顿或双极功率晶体管。LM4702驱动器芯片是美国国家半导体的第一款功率放大器输入级，尤其适用于高性能音响系统。而LME49811芯片可以驱动输出级，将500W以上的单端输出功率输入到8-Ohm 负载。这款芯片的压摆率高达 40V/us，输出驱动电流高达9mA，而输出电压噪声只有100uV。此外，LME49811芯片也可在+/-20V至+/-100V 的广阔电压范围内操作，而且电源抑制比(PSRR)更高达115dB。

个人感觉不会有太大区别，当然要听过后才知道，记得49810输出电流是50ma吧，811省略了一级射随器

tel5169553 · 发表于 2010-5-11 14:24

49811 并不仅仅是 4702的单声道，而是有改进几处地方的。比如说 4702 的高频问题等。
下面是摘录此 ic 设计师的话。呵呵。此人极力推荐使用 49811，并且说他diy 的功放把他自用的krell 200 都干掉了。

The LME49810 was designed as higher output current driver for live music amplifiers and has 50 ma of output current. To get the extra output current (the LME49811 has 7ma) an A/B output stage was added to that part (the 811 has a class A output stage). There were also some minor changes made to the input stage on the LME49811 (one was a suggestion by Bob Pease which is a great story I might tell everyone sometime). I prefer the sound of the LME49811 to the 810 (I did listen to both parts on the same circuit board with minor changes) but they are very close to each other. If you need more than 300w I would use the 810. For 300w or less the 811 is the way to go.

Mark / Audioman54

http://www.diyaudio.com/forums/s ... mp-inflation-3.html

tel5169553 · 发表于 2010-5-11 14:25

The extra compensation circuit for the 4702 and 49811 is actually a noise gain compensation circuit not an extra compensation circuit. I did not know that either and one of our Masters Stanford grads pointed out to several of us the difference. Young college kids actually can be of use sometimes! It is mandatory for that 75pf and 3.3k resistor to be there!!! You will have osc problems coming out of clipping if it is not there.

tel5169553 · 发表于 2010-5-11 14:26

49811 并不仅仅是 4702的单声道，而是有改进几处地方的。比如说 4702 的高频问题等。
下面是摘录此 ic 设计师的话。呵呵。此人极力推荐使用 49811，并且说他diy 的功放把他自用的krell 200 都干掉了。

The LME49810 was designed as higher output current driver for live music amplifiers and has 50 ma of output current. To get the extra output current (the LME49811 has 7ma) an A/B output stage was added to that part (the 811 has a class A output stage). There were also some minor changes made to the input stage on the LME49811 (one was a suggestion by Bob Pease which is a great story I might tell everyone sometime). I prefer the sound of the LME49811 to the 810 (I did listen to both parts on the same circuit board with minor changes) but they are very close to each other. If you need more than 300w I would use the 810. For 300w or less the 811 is the way to go.

Mark / Audioman54

http://www.diyaudio.com/forums/s ... mp-inflation-3.html

tel5169553 · 发表于 2010-5-11 14:27

而且，49811 电路和 49810 的还稍微有点不同。呵呵。49811 更加保真。

tel5169553 · 发表于 2010-5-11 14:31

喔。有关于49811 的好消息。谢谢。
不过 49811 电路和 49810 稍有不同。设计师建议增加2个元件，这样更保真。能否麻烦wj_88 能再设计一个电路板？我可以提供原理图。

wayne · 发表于 2010-5-11 15:16

千片报价才3.3美金，国内居然卖4，5十块，价格贵是阻碍其普及的原因

tel5169553 · 发表于 2010-5-11 15:54

but it was my impression that the LME49810 was designed a bit more for PA applications, the LME49811 a bit more for high end AV.

落花萧然 · 发表于 2010-5-11 20:22

49810还没玩儿呢～～

老兔有点懒 · 发表于 2013-1-20 19:55

回复 7# tel5169553

希望玩玩49811

一生中最爱 · 发表于 2013-1-21 07:10

49810没有听过不下评论，4702就不怎么的，记得当然听了无线电与电视上第一名的机器。隔壁坛老何的，声音不咋的。

riwa · 发表于 2017-6-3 09:05

可惜芯片买不到了!

avtech · 发表于 2019-8-30 08:07

几年前做的，音质确实不错

[基础知识] 有没有 49811 芯片的？ 现在老外都在用这个芯片了。

[基础知识] 有没有 49811 芯片的？现在老外都在用这个芯片了。