When I opened the cover, I saw a metal bar at the bottom of the module making the whole thing heavier.
Now, let’s discuss the electronics placed inside the module. Nearly all the analog things are here (the card itself has only a circuitry for analog outputs to speaker systems). You may remember that the Platinum model with an internal communication module used AC’97 codec SigmaTEL STAC9721 to serve the analog part. It was the company’s choice since Live!. But in our today’s hero Creative put its stake onto high-quality PCM1804 ADC from Texas Instruments (www.ti.com). These chips coupled with low-noise operational amplifiers are responsible for all the three analog inputs of the communication module. The Texas Instruments website has a detailed description of this ADC. These are the main characteristics of PCM1804:
- Up to 192KHz sampling rate;
- 24 bit capacity;
- 112dB dynamic range;
- SNR: 111dB;
- THD+N: -102dB.
The graph shows that there is a very low harmonics level when the peak of the effective signal is 1kHz. That testifies high quality of the codec. Our tests will show how well Creative used its potential.
CS4392 chip from Cirrus Logic serves as a digital-to-analog converter. The characteristics of this chip match those of PCM1804 ADC:
- Up to 192KHz sample rate;
- 114dB dynamic range;
- THD+N: 100dB.
You see a flow-chart for CS4392 DAC. Note that the codec features separate volume regulation scheme, which stands before the digital-to-analog conversion. The volume is controlled discretely with 1dB increment, which is done with the digital volume regulator on the front panel of the communication module.