這個USB音效卡是跟Praxis Measurement System三個月前一起購入的，購入原因是Liberty Instrument網站推薦這張卡搭配筆電，看在M-Audio在專業領域的名氣，產品應該不會太差，雖然是七八年前的產品。以下是簡單心得：
優點：
1. 體積小
2. 有光纖輸出入
缺點：
1. 由於很老的產品，這張卡只支援USB 1.1，最大的不滿是雖然號稱96kHz/24bits，不過竟然是要在半雙工下才能達到96kHz，也就是說，只能在撥放和錄音中選一開啟，若是雙向同時開啟，則最高只能支持48kHz/24bits，雖說不影響音頻測量，總有上當的感覺。
2. 價格不具競爭力，以USD$100左右的價位，不如買Amazon正在跳樓拍賣，只要USD$89的EMU 0202。
3. 規格相對不佳，承上，EMU 0202可是號稱A/D D/A都有 SNR>112dB的實力，而且取樣率更是高至192 kHz，所有接頭鍍金，規格全面勝出。
當然啦，這些缺點是跟假想敵EMU 0202做比較，不然的話Transit已經ˋ是非常夠水準的音效卡了，尤其是他有S/PDIF輸出入。網路上有些人把這張卡當成PC音源輸出，只使用Line-out，操作在96kHz，不過它的THD不是太理想，也許可以透過電路修改來改善吧。
附上RMAA測試數據，測試條件：Line out->Line in loopback
RightMark Audio Analyzer test report
| Testing device | Transit USB Out 1/2 |
| Sampling mode | 24-bit, 48 kHz |
| Interface | MME |
| Testing chain | External loopback (line-out - line-in) |
| RMAA Version | 6.2.3 |
| 20 Hz - 20 kHz filter | ON |
| Normalize amplitude | ON |
| Level change | -0.1 dB / 0.0 dB |
| Mono mode | OFF |
| Calibration singal, Hz | 1000 |
| Polarity | correct/correct |
Summary
| Frequency response (from 40 Hz to 15 kHz), dB |
+0.03, -0.01
|
Excellent
|
| Noise level, dB (A) |
-93.9
|
Very good
|
| Dynamic range, dB (A) |
93.8
|
Very good
|
| THD, % |
0.0010
|
Excellent
|
| THD + Noise, dB (A) |
-87.5
|
Good
|
| IMD + Noise, % |
0.0057
|
Excellent
|
| Stereo crosstalk, dB |
-94.0
|
Excellent
|
| IMD at 10 kHz, % |
0.0059
|
Excellent
|
| General performance |
Very good
|
Frequency response
| From 20 Hz to 20 kHz, dB |
-0.07, +0.04
|
| From 40 Hz to 15 kHz, dB |
-0.01, +0.03
|
Noise level
|
Left
|
Right
|
|
| RMS power, dB |
-92.7
|
-92.7
|
| RMS power (A-weighted), dB |
-93.9
|
-93.9
|
| Peak level, dB FS |
-77.3
|
-75.6
|
| DC offset, % |
-0.0
|
-0.0
|
Dynamic range
|
Left
|
Right
|
|
| Dynamic range, dB |
+92.7
|
+92.7
|
| Dynamic range (A-weighted), dB |
+93.9
|
+93.8
|
| DC offset, % |
-0.00
|
-0.00
|
THD + Noise (at -3 dB FS)
|
Left
|
Right
|
|
| THD, % |
+0.0010
|
+0.0010
|
| THD + Noise, % |
+0.0047
|
+0.0048
|
| THD + Noise (A-weighted), % |
+0.0042
|
+0.0042
|
Intermodulation distortion
|
Left
|
Right
|
|
| IMD + Noise, % |
+0.0057
|
+0.0058
|
| IMD + Noise (A-weighted), % |
+0.0050
|
+0.0050
|
Stereo crosstalk
|
Left
|
Right
|
|
| Crosstalk at 100 Hz, dB |
-92
|
-93
|
| Crosstalk at 1000 Hz, dB |
-93
|
-93
|
| Crosstalk at 10000 Hz, dB |
-81
|
-80
|
IMD (swept tones)
|
Left
|
Right
|
|
| IMD + Noise at 5000 Hz, |
0.0058
|
0.0059
|
| IMD + Noise at 10000 Hz, |
0.0058
|
0.0060
|
| IMD + Noise at 15000 Hz, |
0.0059
|
0.0058
|
