Internal Generator Test

[Tranquility Bass]

Introduction:

The Ultimate-Preamplifier has a built in precision digital waveform generator which is useful for doing spot checks and distortion measurements. When generating waveforms such as sinewaves it uses 32bit precision at 192kHz sample rate so one would expect the distortion of this generator to be very low and way below the distortion and noise of anything else in the chain such as the DAC.

Test Methodology:

To verify the performance of the built in generator we need to exclude anything else in the signal path such as the DAC in the preamp and the ADC in the measurement analyzer which will only swamp the measurements with their own distortions. We can do this in the same way we tested the on-board ADC by feeding the resultant digital signals words directly to the dScope III analyzer via the S/PDIF output on the back of the Preamp since the Coax output can handle the native 192kHz resolution of the test generator.

Conclusions:

From the test results below what can we say except to note that any noise and distortion artifacts are way below anything else in the chain and are so low they don't even indicate on the distortion meters ! So indeed the built in test generator can be used as a reference standard waveform generator !!

[Tranquility Bass]

Measured directly from the S/PDIF output of the Preamp