Passive I/V vs. traditional I/V, FFT pics.

[A 8]

The following pics are taken with SpectraLab using a laptop on batteries and a slightly modified USB soundcard also run on batteries.

The passive I/V DAC is a balanced PCM1704K with a resistor (100ohms) between I out on the dacs, nothing xtra to ground.
The measurements for this dac are taken at the poweramp output.
The PCM1704 passive I/V is being compared to the Denon 2900 DVD using the BB PCM/DSD 1792 and standard I/V etc basically (different opamps) as described in TI's datasheets. These pics are directly from line out. The spec on this player says 0.0009% THD @ 1kHz.

First out is the Denon @-20dB..

[A 8]

PCM 1704 passive I/V @ -20dB

[A 8]

the denon @ -60dB

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The passive PCM1704 @ -60dB

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Denon @ -90dB

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The PCM1704

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Denon @ -100dB (16 bit data)

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The passive PCM1704 dac @ -100dB (16bit data)

[A 8]

Considering my expectations based on the general consensus on this forum about passive I/V I think this is pretty good and way beyond my expectations.

The following pics are direct spdif dumps from the same source.

[A 8]

-60dB