列印
上層分類: Digital audio source and Digital Signal Processing
點擊數: 11862

這個玩具是為了搭配新買的AKG 840KL耳機,在公司聽音樂用的。0204本來的用途是供專業錄音、作曲或是現場演唱用,所以有些設計例如零延遲監聽等是我們一般用不到的,不過它的一些專業特性例如極低延遲,極低clock jitter以及專門為了推動監聽耳機而獨立設計的耳機擴大機,都是對於音質有正面幫助的,由於這玩意不論外觀與規格都和EMU上一代產品0202很像,我花了一點功夫才整理出它們的差異:

1. 0204為二進四出,0202為二進二出,0204多出的二出和耳機接頭共用。
2. SNR改進,根據國外論壇的資料,0204採用0404的A/D與D/A 'Miracle DAC AK4396,SNR從0202的112dB進步到117dB。

結至目前為止,我是相當滿意這張音效卡的表現,滿意到我打算再買一張在家裡用,我相信只要好好的調整,這個音效卡足以PK大部分高價CD player+DAC。

優點:
1. 類比式耳機音量調整旋鈕
2. 全機接頭鍍金
3. 規格佳

缺點:
1. EMU網站上竟然沒有提供驅動程式下載
2. 聲道分離度只有不到90dB,比M-Audio Transit差了快10dB
3. 搭配公司的PC,每次重開機都不能成功抓到0204,必須手動插拔USB cable

附上RMAA測試報告,有48kHz與192kHz兩種,在測試不同sampling rate之前,有確實把0204驅動程式的sampling rate設定值更改。關於聲道分離度有點小問題仍在確認中,所以這項請大家先忽略,RMAA測試報告noise floor跟使用的PC有關,我測試時一律使用Asus EeePC 1000H電池模式,這是我幾台電腦裡面測試數據最好的一台PC,除聲道分離度外,可以看到0204數據實在好得嚇人,離官方數據不遠。

 


 

RightMark Audio Analyzer test report

Testing device E-MU 0204 | USB
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 -0.2 dB / -0.3 dB
Mono mode OFF
Calibration singal, Hz 1000
Polarity correct/correct



Summary

Frequency response (from 40 Hz to 15 kHz), dB
+0.04, -0.08
Excellent
Noise level, dB (A)
-112.9
Excellent
Dynamic range, dB (A)
112.7
Excellent
THD, %
0.0009
Excellent
THD + Noise, dB (A)
-97.4
Excellent
IMD + Noise, %
0.0016
Excellent
Stereo crosstalk, dB
-86.0
Excellent
IMD at 10 kHz, %
0.0025
Excellent
General performance
Very good



Frequency response



From 20 Hz to 20 kHz, dB
-0.23, +0.04
From 40 Hz to 15 kHz, dB
-0.08, +0.04



Noise level



Left
Right
RMS power, dB
-111.5
-111.7
RMS power (A-weighted), dB
-112.7
-113.0
Peak level, dB FS
-89.5
-86.8
DC offset, %
+0.0
-0.0



Dynamic range



Left
Right
Dynamic range, dB
+111.5
+111.7
Dynamic range (A-weighted), dB
+112.6
+112.9
DC offset, %
+0.00
+0.00



THD + Noise (at -3 dB FS)



Left
Right
THD, %
+0.0009
+0.0009
THD + Noise, %
+0.0011
+0.0011
THD + Noise (A-weighted), %
+0.0014
+0.0013



Intermodulation distortion



Left
Right
IMD + Noise, %
+0.0017
+0.0015
IMD + Noise (A-weighted), %
+0.0013
+0.0013



Stereo crosstalk



Left
Right
Crosstalk at 100 Hz, dB
-103
-105
Crosstalk at 1000 Hz, dB
-85
-85
Crosstalk at 10000 Hz, dB
-66
-66



IMD (swept tones)



Left
Right
IMD + Noise at 5000 Hz,
0.0030
0.0031
IMD + Noise at 10000 Hz,
0.0019
0.0019
IMD + Noise at 15000 Hz,
0.0026
0.0024

 


 

RightMark Audio Analyzer test report

Testing device E-MU 0204 | USB
Sampling mode 24-bit, 192 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 -0.2 dB / -0.3 dB
Mono mode OFF
Calibration singal, Hz 1000
Polarity correct/correct



Summary

Frequency response (from 40 Hz to 15 kHz), dB
+0.01, -0.11
Excellent
Noise level, dB (A)
-112.8
Excellent
Dynamic range, dB (A)
112.9
Excellent
THD, %
0.0010
Excellent
THD + Noise, dB (A)
-97.0
Excellent
IMD + Noise, %
0.0016
Excellent
Stereo crosstalk, dB
-86.0
Excellent
IMD at 10 kHz, %
0.0024
Excellent
General performance
Very good



Frequency response



From 20 Hz to 20 kHz, dB
-0.36, +0.01
From 40 Hz to 15 kHz, dB
-0.11, +0.01



Noise level



Left
Right
RMS power, dB
-111.4
-111.4
RMS power (A-weighted), dB
-112.6
-113.1
Peak level, dB FS
-70.6
-71.0
DC offset, %
-0.0
+0.0



Dynamic range



Left
Right
Dynamic range, dB
+111.5
+111.8
Dynamic range (A-weighted), dB
+112.8
+113.0
DC offset, %
-0.00
-0.00



THD + Noise (at -3 dB FS)



Left
Right
THD, %
+0.0010
+0.0010
THD + Noise, %
+0.0012
+0.0011
THD + Noise (A-weighted), %
+0.0014
+0.0014



Intermodulation distortion



Left
Right
IMD + Noise, %
+0.0016
+0.0015
IMD + Noise (A-weighted), %
+0.0013
+0.0013



Stereo crosstalk



Left
Right
Crosstalk at 100 Hz, dB
-98
-98
Crosstalk at 1000 Hz, dB
-85
-85
Crosstalk at 10000 Hz, dB
-66
-66



IMD (swept tones)



Left
Right
IMD + Noise at 5000 Hz,
0.0029
0.0030
IMD + Noise at 10000 Hz,
0.0018
0.0018
IMD + Noise at 15000 Hz,
0.0025
0.0023