Output noise level of ADAU1701?
Hi There!
I'm designing a power amplifier that uses ADAU1701 as processor. I'm at the stage of the electronic circuit design and I have one "stupid" question: Is the output noise of ADAU1701 small enough that I can connect the DAC output directly to the power amplifier without a potentiometer? The amplifier is high power (500W or more) and the loudspeakers are very sensitive, let's say 100 dB / W. So, any noise can be easily heard.
In case it is, I'll connect the DSP directly to the power amplifier and control the volume by software. Otherwise, I'll need an analog potentiometer between the DSP and the AMP, so DSP operates at 0 dBu and the potentiometer controls the volume by attenuating the signal, thus, eliminating the DAC noise as consequence.
Your input is highly appreciated. I'm currently designing the board, so that is very important right now.
Thanks!
Audio Signal Processors
SigmaDSP Audio Processors
adau1701
I'm working on a similar project and in the end found the noise level too high for our purposes. It's not really bad, but we need it quiet. I'm in the process of adding a quieter DAC to my board.
Without a listening test, it might be hard to tell what is acceptable and what is not. Keep in mind that the DACs have a better SNR than the ADCs, so if your audio source is analog, then the weak point in the signal chain and the source of the most noise might actually be on the source side.
If you want a higher performance standalone DAC, the AD1955 might be a good fit.
AD1955 DAC Performance Specs
Typical 120 dB SNR/DNR (not muted) at 48KHz Sample Rate (A-Weighted Stereo)
Typical 123 dB SNR/DNR (Mono)
A potentiometer on the output circuit might be a good solution as well.
Got it! I'm definitively adding a potentiometer then.Thanks!
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