I have just tested the M-Audio Audiophile 192
It is also a PCI sound card with S/PDIF input/output, support for Asio and WDM drivers. I got it around 119 €. It can record 24 bits PCM data at 8, 9.6, 11, 12, 16, 22, 24, 32, 44.1, 48, 88.2, 96, 176.4 and 192 kHz. It is possible to select the clock synchro method, either internal or S/PDIF input signal.
I will just relate the PCM recording through its S/PDIF input.
I used several 192kHz 24bits files to be recorded (I also used the same files when previously testing ASUS Xonar D2/PM):
- 1 file containing all possible values taken on 24 bits samples. File content: [ 0 0 1 1 2 2 ... 16777214 16777214 16777215 16777215 ].
- 1 file containing a non-null constant value during 30 minutes. File content: [ 16777215 16777215 16777215 16777215 ... 16777215 16777215 ].
- 1 file containing silence during 30 minutes. File content: [ 0 0 0 0 ... 0 0 ].
- 1 file containing real music.
Before entering test details, I found a limitation in the M-Audio drivers concerning clock synchro. WDM drivers can't be used to record while synchronizing on the S/PDIF clock, and on the opposite, ASIO drivers can't record while synchronizing on the internal clock. This limitation was hit using several recording software (Sonar, GoldWave, Audacity).
Here are the tests I conducted: 1- Recording a consumer S/PDIF PCM signal
The PCM signal was played from another computer using foobar with kernel streaming plugin. a- Using WDM driver and internal synchro: Failure
- The problem encountered here seems to be jitter. 2 samples were sometimes added to the signal, and samples around were kind of stretched.
Here is a concrete example: playing the sequence [ 1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 ]
recording was [ 1 1 2 1 3 3 4 3 5 4 6 5 7 6 8 7 8 8 9 9 ]
. b- Using ASIO driver and S/PDIF synchro: Success 2- Recording a professional S/PDIF (aka AES/EBU) PCM signal played from the Audiophile 192 itself
The S/PDIF output has the possibility to send AES/EBU data (switch on the driver side). I directly connected its S/PDIF output to its S/PDIF input, and played using foobar and ASIO playback driver. Unfortunately ASIO driver can't be used for both playback and recording, so I could not test ASIO recording with this configuration. a- Using WDM driver and internal synchro: Success
3- Recording a professional S/PDIF (aka AES/EBU) PCM signal played from Forssell MADC-2 output
- No problem. Jitter can't happen as the same clock is used for both playback and recording. This test validates that the Audiophile 192's S/PDIF input accepts AES/EBU data correctly.
For this test, I can't check for sure if the recording is bit-perfect as my source is analog when going into MADC-2.
However, I did not hear/see any drop-out or distortion when recording silence, sine waves or music, both with WDM driver (Internal clock) and ASIO driver (S/PDIF clock).
I suspect that WDM driver recording using internal clock synchro has induced jitter, but it was impossible to hear it. Conclusion: M-Audio Audiophile 192 can clearly record bit-perfectly
both S/PDIF and AES/EBU signals (when synchronized on the S/PDIF signal).
Jitter was measured where it was supposed to occur (only when the source was an external device and the clock synchro was internal), nothing abnormal.
Other notes I have taken:
- Concerning the previously tested ASUS Xonar D2/PM (for consumer S/PDIF recording only), its clock synchro was certainly S/PDIF also, as I got the exact same number of recorded samples. Just the values were modified. With Audiophile 192, jitter resulted in the addition of new samples that were kind of interpolating the source signal.
- The only 2 causes of distortion I have seen along my tests were bad software drivers and jitter.
- I did neither test sample rates <192khz nor 16bits recording. I assume that if 192kHz/24bits records bit-perfectly, other formats should be ok.
If I happen to test another gear, I will continue posting my results here.
I hope those results will be helpful for others. If you want me testing specific features or configs that I may have missed, feel free to ask, I will try my best.