NAS/MEDIA PLAYER線性電源pcb

billymud

johnme 發表於 2014-4-9 12:53
Agree with you that ripple rejection is only one aspect of the regulator performance.

As I am wor ...

C_hing, you keep working on Series Requlation, why not give Shunt Requlation a chance ?
using Shunt Req, (i suspect ) to minimize current variation would manage the NAS and DAC to do a better "audio" job.
-- who knows ?

edison133

Using "Shunt Req" is not good idea for NAS power, because it produce  a lot of hat!
And then hat will produce noise!

edison133

Actually AMB circuit already do the good job,
I used my 51/2 AC voltmeter to check and find noise level is -116.8dB@ no load. -93.4dB@1A load.
See my blog for more detail        

billymud

edison133 發表於 2014-4-11 10:36
Actually AMB circuit already do the good job,
I used my 51/2 AC voltmeter to check and find noise l ...

good to know.

johnme

billymud 發表於 2014-4-11 03:23
C_hing, you keep working on Series Requlation, why not give Shunt Requlation a chance ?   ...

Yes, I will consider this option.

I hear that some people are using shunt reg to drive T-amp @ 3A.

Of, it requires large heat sink.

johnme

edison133 發表於 2014-4-11 10:32
Using "Shunt Req" is not good idea for NAS power, because it produce  a lot of hat!
And then hat wil ...

Yes, you are right.

There is a trade-off between noise and transient response.

Shunt regulator provides better transient response.

But, it has a drawback: lot of heat! (hence, size)

johnme

edison133 發表於 2014-4-11 10:36
Actually AMB circuit already do the good job,
I used my 51/2 AC voltmeter to check and find noise l ...

Yes, the AMB PSU is very good.

To me, there is no clear winner when comparing LT1084 and Sigma11 for NAS in terms of sonic performance.

Sigma11 sounds more relaxing and enjoyable.

The LT1084 excels in reproduction of instruments' texture and sounds a bit more dynamic.
It pin-points instruments better than LT1084.

Honestly, I am happy with both.

After I get the PCBs (hopefully, get them by this week),
I will experiment different compensation and value of the Cdom in Sigma11.
Also, I will try different method of bypass & decouple for LT1084. (see attached pdfs)

Hope that I can push the sonic performance further.

The file size of AN104f is too large, download by yourself:

http://cds.linear.com/docs/en/application-note/an104f.pdf

Edison133, I am interested in writing a blog too.
Can you tell us about how to set up a blog?

edison133

johnme 發表於 2014-4-11 15:52
Yes, the AMB PSU is very good.

To me, there is no clear winner when comparing LT1084 and Sigma11  ...

Wa..... it is very good referencer for power supply!!!
And also built the blog is very easy, suggest you use Google blogger!
You only need gmail account to open this function.   

johnme

Kenneth_obee兄,
你都做左唔少sigma11,
同埋都有玩nas同cas,
比d意見大家啦~

billymud

johnme 發表於 2014-4-3 21:34
手痕做多個sigma11 modified版,
用tmc compensation,
但係可以還原做原本sigma11,

your final build may be look like this !