Is ADAU1701 good enough for real speakers?

[CyberPit]

I have designed several types of ADAU1701 boards. Now I can say the ADAU1701 embedded DAC is good enough for most audio applications. (Such as a crossover or Speaker EQ compensation)
The output level can be adjusted to 2Vrms with my circuit design. (Also, the absolute phase corrected)

• FreeDSP Classic SMD A/B
• FreeDSP Classic SMD A/B plus ][
• FreeDSP Catamaran A/B

On the other hand, ADAU1701 embedded ADC has the characteristic of increasing distortion near the full-bit level. It will not be a matter if we use the DIR instead of the embedded ADC. There is one big constraint that exists when using S/PDIF. The ADAU1701 doesn't have ASRC, so the DSP should run with the input source's sampling rates. The cut-off (or turn-over) frequency will change if you switch the fs, such as 44.1kHz/48kHz/96kHz, etc.

FreeDSP Catamaran solved this ADC behavior with a special differential ADC operation. Here are the single-end and differential ADC operation characteristics.

ADAU1701 Single-Ended ADC to Embedded DAC overall Distortion:


AUAU1701 Differential Operated ADC to Embedded DAC overall Distortion


I will say, the differential-operated ADAU1701 ADC performance is more than enough.
If you always play the single Fs, I recommend using the digital input.


CyberPit

 

[HumbleDeer]

Yes, 0.9 Vrms is the max output. Here's a clarification:

You are correct, the max RMS DAC voltage is 0.9 V. I shouldn't trust my faulty memory. I would still contend that is low compared to many DACs whose outputs are 2 or 4 V RMS max. In the end it just means you need select an amplifier with the correct gain to match the 0.9 V RMS max output.

Ern, I think you might be confusing yourself by using RMS and max in the same phrasing. It's either/or, not "RMS max". It's-either the RMS rating in volts or max rating in volts.

 

[ernperkins]

I think we’re getting tied up in semantics and cluttering up the thread, so I'll send you a message.