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标题: 学习一下 AKSA 电路 [打印本页]

作者: e3po 时间: 2011-2-14 13:03
标题: 学习一下 AKSA 电路

http://users.tpg.com.au/users/gerskine/greg/default.htm

作者: 倾听 时间: 2011-2-14 14:59
标题: 回复 1# e3po 的帖子
什么叫AKSA电路啊?

作者: e3po 时间: 2011-4-19 03:18
bu zhi dao ah

i don't know why it's named AKSA

[ 本帖最后由 e3po 于 2011-4-19 15:35 编辑 ]

作者: millwood 时间: 2011-4-19 03:38
Aksa is a line of power amplifier kits designed and sold by Hugh Dean, an Australian hobbyist (originally).

The amp came from Hugh's desire for a simple and good sounding amp. It uses the traditional Linn 3-stage design but focuses on open loop linearity, and low open loop gain.

the circuit was originally published at Rod Elliot's website (sound.westhost.com). Rod is another great australian amp designer. but after Hugh started to sell Aksa kit, that page has been taken down.

There is no published schematic + parts list for the aksa amp - Hugh was fairly rigid when it comes to his ip rights.

the aksa is probably THE most built power amp kit ever, and it sounds great.

hugh has a new website and from what I understood he is selling actively into China. so maybe you will run into one of his customers here.

作者: e3po 时间: 2011-4-19 07:08

原帖由 millwood 于 2011-4-19 03:38 发表
Aksa is a line of power amplifier kits designed and sold by Hugh Dean, an Australian hobbyist (originally).

The amp came from Hugh's desire for a simple and good sounding amp. It uses the tradition ...

thanks, man

作者: e3po 时间: 2011-4-19 07:29
标题: 回复 4# millwood 的帖子
btw,

last year, you mentioned some fast regulated power supply circuit for powerAmps, but I was too lazy to put down it's name.

Could you shed some light again this time?

作者: cfanzfr 时间: 2011-4-20 13:23
OK!学习了！

作者: millwood 时间: 2011-4-20 17:47

some fast regulated power supply circuit for powerAmps

you have to help me here. what was the context of that discussion?

作者: e3po 时间: 2011-4-20 18:29

原帖由 millwood 于 2011-4-20 17:47 发表

you have to help me here. what was the context of that discussion?

we / people were talking about adding regulated power supply to JLH1969 power amp.
You thought it might be a bad idea, but pointed out some regulated power supply circuit(s) being pretty brilliant...

I can recall only a few think pieces, sorry , my memory is getting bad.

作者: millwood 时间: 2011-4-21 05:03
most of the regulated power supplies rely on negative feedback to produce stable DC voltage into a steady load. they work great for class A amplifiers.

Class B amplifiers represent a dynamic load. To produce the transient output required by the power amp, a regulated power supply has to have better transient performance than the power amp they are powering -> essentially the power supply is a power amp of better spec.

so your choices for Class B amplifiers are really 1) unregulated power supplies; and 2) open loop power supplies. In the 2nd category, a widely used choice would be a capacitance multiplier: it is essentially an emitter follower, with very fast transient speed, but its ripple performance depends on the beta of the transistors used, and load current you design it for. Because of that, a capacitance multiplier isn't realistic for anything bigger than 5 - 6 amps (dynamic).

hope it helps.

BTW, the extreme of dynamic load would be a class D amplifier and powering it with a smps is still an unresolved issue. all the commercial solutions in that area are patented.

作者: e3po 时间: 2011-4-21 05:34
标题: 回复 10# millwood 的帖子
Thanks for your input!

in 1996 LT already had this "LT1575 UltraFast Linear Controller Makes
Fast Transient Response Power Supplies"

http://cds.linear.com/docs/Application%20Note/an69f.pdf

Is there something alike that we can DIY ?

作者: millwood 时间: 2011-4-21 05:56
I am not sure if you could diy that part - it looks quite good. take a look at figure 4 and that transient response isn't great but still very good.

it would be quite tricky to manage oscillation in a fast part like this.

作者: e3po 时间: 2011-4-22 11:48

原帖由 millwood 于 2011-4-21 05:56 发表
I am not sure if you could diy that part - it looks quite good. take a look at figure 4 and that transient response isn't great but still very good.

it would be quite tricky to manage oscillation i ...

thanks man.

I googled some key words and found one of your post related to regulators:

http://tangentsoft.net/elec/opamp-linreg.html
http://bbs.hifidiy.net/viewthread.php?tid=105017

it's very educational.

作者: e3po 时间: 2011-6-20 04:17
复习一下

........

作者: e3po 时间: 2012-10-7 14:08

找walt jung super regulator 稳压电路

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