ccw

ASUS Xonar Essence ST
http://www.price.com.hk/product.php?p=119889
+
LME49990
http://www.ebay.com/itm/DUAL-SOI ... hash=item2c743398f3

ccw

引用:

原帖由 ~Mars~ 於 2013-11-8 10:10 發表
sold a second hand x-fi

buyer cant get it to work, requests refund now

ccw

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原帖由 Richteralan 於 2013-11-8 10:57 發表
Stopped buying sound card ages ago.....

Now just use digital out to pass all signal to external DAC

Actually I wonder how much difference can there be by separating the DAC from the electric noise,
and are you connecting to the DAC by optical connection?
Do we need a "decent" sound card to output that optical signal, if that's the case?

ccw

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原帖由 KvCC 於 2013-11-9 04:59 發表

我岩岩去左買STX

Do also buy the LME49990

ccw

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原帖由 KvCC 於 2013-11-9 10:51 發表

就咁插落去就可以? (Yes, remove the original, install the new IC on the same slot in the correct orientation)要唔要焊?(Not necessary, depends on which ICs you are getting) 我完全唔識搞呢D
新買既仲想留返個保養

For LME49990, nothing to do if you buy from this seller:
http://www.ebay.com/itm/DUAL-SOI ... hash=item2c743398f3
All you need to do is to remove the cover, change the IC on the socket by fingers just like changing other parts in the PC, no soldering needed.
Just take care not to damage the other parts on the card.

The ic themselves are surface mount, and you need 2 to operate in a pair for 1 slot,
for ASUS STX you need 3 pairs for 3 slots.

Sure you can still enjoy your current card for some days before you have decided to improve it,
but the fact is the original ICs coming with the cards are not really good.

This thread is a detailed discussion about how different ICs are performing:
http://www.head-fi.org/t/421890/ ... -impressions-thread

[ 本帖最後由 ccw 於 2013-11-9 11:05 編輯 ]

ccw

引用:

原帖由 KvCC 於 2013-11-9 12:12 發表

等我玩夠同習慣左先換
咁先覺得抵
一步登天 下次再上會好貴

Ya, that's why I said you can have fun with it for now.
Anyway the difference is obvious enough to distinguish itself from the Realtek and you will know where your money has gone to.

ccw

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原帖由 cheungmanhoi 於 2013-11-10 22:40 發表

你講!
你係唔係收左ti錢  係咁毒人買49990

收左TI ic gum lor

ccw

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原帖由 cheungmanhoi 於 2013-11-10 23:46 發表

apply free sample 是常識吧

Actually you can do it, make sure wk doesn't know is fine.

ccw

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原帖由 cheungmanhoi 於 2013-11-11 00:59 發表

u say apply ti sample ?






actually i apply some opamp(on) for myself already

"Hello, is it WK? Sandbo here, I want to tell you your subordinate CMH ......."

ccw

引用:

原帖由 KvCC 於 2013-11-11 10:31 發表

http://www.hkepc.com/forum/viewthread.php?tid=1990645
我見到呢個有團購 得唔得架 如果平既可以

I am not sure with that offer,
if you are not going to solder on your own,
check with the seller to make sure you are getting the soldered IC pair on a mount (Dual LME49990 on one DIP8 mount),

You may just ask if what they are offering is the same, finished product on this page:
http://www.ebay.com/itm/DUAL-SOI ... hash=item2c743398f3

Certainly, you can consider any of the other ICs listed there to try, whether they are suitable it depends on the mount (DIP8 will be fine)
and better to see if someone was using it on Head-Fi link I gave on the previous page.

*Some information if you are not sure about the opamp on ASUS card:
-There are 2 types of ICs basically, Single channel, or Dual channel.
-LME49990 is single channel, that's why you need 2 of them for 1 slot.
-Some other ICs are Dual channel, you just need 1 of them for 1 slot.

For ASUS Xonar Essence STX, there are 3 slots: 1 for Buffer, 2 for Headphone Out
-You will need 1 Dual Channel IC for Buffer slot
-And need 2 SAME TYPE of Dual Channel IC for amplifier circuit
That's the reason you need 3 pieces of Dual Channel IC (or 3 pairs of Single Channel ICs) for the card.

-The Buffer slot affects BOTH LINE-OUT and HEADPHONE-OUT.
-The 2 SAME TYPE IC slots affect only the HEADPHONE-OUT
It means that depending on your configuration, if you use only the Line-out,
you can get just 1 pair of LME49990; if you use also the headphone out, you will need 3 pairs.

As a reminder, with some other Dual-channel ICs, like LME49720NA, as it is Dual-Channel in nature, and is already on DIP8,
you just need 1 of that IC, and without any mount or soldering you can install it on your sound card.

Whenever you are buying an IC for your sound card, here are what you need to check:
-What mount is it having? (Surface mount-->need adapter+soldering; DIP8-->nothing needed, can be installed directly)
-Is it single channel or dual channel?(Single channel-->Need 2 ICs to work as a pair for 1 slot; Dual Channel-->1 piece of IC can work for 1 slot)
-Is it compatible with the card? (Oscillation! Check if someone has this problem with the combination "XXX Sound Card + YYY IC")
-Is the IC having design flaw? (LME497XX/LME498XX are said to be having design flaw that their bass is much supressed, while LME49990 can get rid of this)


I have tried to summarize what I have understood after reading the long thread on Head-Fi, hope it helps.

[ 本帖最後由 ccw 於 2013-11-11 20:50 編輯 ]

ccw

引用:

原帖由 KvCC 於 2013-11-11 20:35 發表

好詳細
多謝講解 全部明晒喇 等我研究下先

Not really la, you're very welcome.
I somehow worry if I have said something wrong, as I am not familiar with Audio opamps at all