嗨，請問大家的UAB 在播音樂時會有像FM 廣播的noise 嗎？

[kutkm_ti]

嗨，請問大家的UAB 在播音樂時會有像FM 廣播的noise 嗎？

我弄過PCM2702,PCM2707,無論外接電源
or USB 電源都會像FM 廣播的noise。。
我有加Inductor ，無論USB的5V-VCC,GND,D+ ,D- 都有加Inductor（線圈）.
而且3.3V，5V 有各自的穩壓。。
播音樂時才有像FM 廣播的noise… 波波聲。。
請問他是從那兒傳來的？要如何解決？

[botton]

請問一下您用的主機板是哪一張啊...
如果是VIA的南橋
裝一下VIＡ USB FILTER
跟VIA PFD
這兩個修正程式，說不定會解決....
參考看看

[kutkm_ti]

http://www.viaarena.com/?PageID=298#windows2

USB Drivers


USB Filter Patch - USB v1.0

This patch fixes very specific issues under specific circumstances, described below. Users who are unsure as to whether they should install the patch can be assured that if they do install the patch, even if it is not necessary, it will cause no harm to their system. The patch will detect your systems configuration and install only when necessary. The patch will only install on certain older VIA host controller revisions. Under these circumstances, the patch will resolve the following issues:

Fixes the issue when a connected usb hub that has no usb devices connected will be disabled after another usb hub is attached at another available root port.
Fixes the issue when transferring large of amounts of data, the system will hang.
Avoids noise from a USB audio converter or speaker.
Supports a usb 1.0 add-on card. Note that this patch does not assist with problems concerning USB 2.0 add-on cards.
Under Win2000/XP: This patch will save all register values in the memory before a system enters Stand By mode and then restore those registers when the systems resumes. This therefore avoids the situation where USB devices are not ready for use after a resume from Stand By mode.
Note: This patch should also be used as a driver for PCI USB cards that have the VT83C572 chip.



i will test it, maybe can work...

[JY]

你機器上用的是哪顆op? 我那邊用上了AD797也會有這種問題...
不然就試試看把後端接的放大器的輸入組抗降低一點...

--
換個FET的通常問題可以解決... 不過有時候TL071是例外...

[kutkm_ti]

after install USB Filter Patch - USB v1.0
i felt the noise is less than before,but still have a little noise.
but it is ok.

i use AD8610.