Ultra low level signal resolution 1kHz @ -90dBFS

[Tranquility Bass]

Test Methodology:

In this test we are looking at how the DAC is good at resolving very low level signal levels or in other words its micro-dynamic resolving capability. In this case we feed each channel a low level digital signal of -90.31 dBFS which corresponds to a full-scale (0dBFS) signal divided by 32768 or a reduction of signal magnitude by 16 bits which is the lowest level for redbook CD ! This is a 32bit DAC so still has plenty of bits left in the tank to resolve this detail

Conclusion:

Even with a reduction of level equivalent to 16bits in magnitude we see the Ultimate Preamplier has no problem and resolves it cleanly compared to the DEQX Premate which adds a lot of noise and distortion to the signal.

[Tranquility Bass]

Below is the real time capture of the Left and Right Channels at -90.31dBFS @ 1kHz 24 bit Wordlength

Below is the FFT Specturm of the output above (Note that any artifacts are buried below -160dB !!)

[Tranquility Bass]

Fig.10 DEQX PreMate, waveform of undithered 1kHz sinewave at –90.31dBFS, 24-bit data (left channel blue, right red).
 


Fig.8 DEQX PreMate, filter operating for Bryston Model T, spectrum with noise and spuriae of dithered 1kHz tone at –90dBFS with: 16-bit data (left channel cyan, right magenta), 24-bit data (left blue, right red) (20dB/vertical div.).

[MichaelH]

Fig.10 DEQX PreMate, waveform of undithered 1kHz sinewave at –90.31dBFS, 24-bit data (left channel blue, right red).
 


Fig.8 DEQX PreMate, filter operating for Bryston Model T, spectrum with noise and spuriae of dithered 1kHz tone at –90dBFS with: 16-bit data (left channel cyan, right magenta), 24-bit data (left blue, right red) (20dB/vertical div.).

Once again proving that the DEQX is a pile of junk.