一直以來我的電腦都遇到一個問題，就是外部USB Audio (Creative EMU-0404 USB)的ASIO Buffer不能太少（>= 256），當太少時就會出現爆/「擦」音。但Buffer過大就會延遲 (Latency)問題，即現場錄音或者玩樂器時明顯感受到延遲。
跟據 SOS 文章，一般可接受的延遲值如下：
Optimising The Latency Of Your PC Audio Interface (soundonsound.com)
- Vocals: This is the most difficult example, because anyone listening to their vocals in 'real time' will have headphones on, and therefore have the sounds 'inside their head'. A latency of even 3ms can be disconcerting in these conditions.
- Drums & Percussion: I suspect most drummers will prefer to work with latencies of 6ms or under, which should provide an 'immediate' response.
- Guitars: Electric guitarists generally play a few feet from their stacks, and since the speed of sound in air is roughly a thousand feet per second, each millisecond of delay is equivalent to listening to the sound from a point one foot further away. So if you can play an electric guitar 12 feet from your amp, you can easily cope with a 12ms latency.
- Keyboards: Even on acoustic pianos there's a delay between your hitting a key and the corresponding hammer hitting the string, so a smallish latency of 6ms ought to be perfectly acceptable to even the fussiest pianists. Famously, Donald Fagen and Walter Becker of Steely Dan claimed to be able to spot 5ms discrepancies in their performances, but the vast majority of musicians are unlikely to worry about 10ms, and many should find a latency of 23ms or more perfectly acceptable with most sounds, especially pads with longer attacks.
就我個人，因為EMU0404有耳返(Real time montoing)功能所以唱歌錄音不是問題，但錄樂器就希望少於8ms.
換了一張 PCIe 的 USB3/Type-C 卡試試
早前因為忍耐不了USB不穩定和想有Type-C接口，所以決定加一張PCIe 的 USB3/Type-C 卡（@2023-11-07 淘寶￥126）。
換上這張卡後，把EMU0404接到後面的USB3接口（有點浪費呢，因為EMU0404只是USB2.0，用不著USB3），用USBTreeView檢查沒有其他佔頻寬的共用著，也把 Buffering ASIO 設定到最低 （SR：48kHz)，開一下StudioOne + Kontakt + 較大的Virtual Instrument)，也用 Foobar2000 試了，確實比之前有改善。
不過在VoiceMeeter下，Foobar2000 在 128/48kHz下還是有一點點爆/「擦」音，但肯定有改善了。
再觀察一段時間應該就知道是否真正改善了。