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The multiplex decoder breaks some new ground compared to the T-109V. It first converts the output of the detector to digital via an AKM 5385, 24-bit, 192 kHz A/D converter. This is a part touted by some as a mastering grade A/D converter. It is more than good enough to fully exceed the frequency, distortion and noise potential of the FM Stereo media. In fact, it has -103 dB S/N+D, -114 dB S/N and 114 dB dynamic range. The T-1000 then uses a TI digital signal processor to synthesize and then cancel the pilot tone. The DSP is followed by an AKM AK4114, 24-bit, 192 kHz Digital Audio Interface Receiver (DAIR). While jitter is not specified for this part, most of the better DAIRs have reduced jitter tremendously compared with a few years ago. Finally, D/A duties are conducted by an Analog Devices AD1853 D/A converter. This part has -104 dB S/N + D, -117 dB S/N (48 kHz stereo), and 116 dB dynamic range (48 kHz Stereo). The output op-amps are the unexceptional JRC5532 parts. I would have liked to have seen better op-amps such as the AD797, OPA627 or at least a OP2134. While the D/A converter parts are in vogue right now and are one of the better parts available in the multi-delta sigma type, I would have personally liked it better if the PCM1704 R2 style DAC had been used. Others will no doubt disagree, but in my view the PCM1704 is the best single IC DAC that I have tested. More about DACs later. Some analog purists will say that they don't want an A/D converter, a DSP or a D/A in their tuner. My comment to them is that this is their loss. With the bandwidth of FM being strongly limited by the 19 kHz pilot carrier, the 48 kHz sampling rate of the digital components should be more than wide enough to prevent information loss. In fact, listening tests (see below) seem to indicate fidelity gains NOT losses.


Regards Rob.

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