Topic: ADI-2 pro output reference levels
I use the adi-2 pro fs (with the last firmware) to execute rooms and devices measurements with REW program on a Mac book pro.
I’ve a question about the output levels.
With an input via USB of a pure sine tone at 1KHz, 0dbfs, the volume set to 0dB, I read from Adi’s TS output with my rms multimeter:
Ref level 4dbu: 1.23v
Ref level 13dbu: 2.85v
Ref level 19dbu: 5.00v
Ref level 24dbu: 5.22v
Theoretically speaking, they should be respectively: 1.23v (aligned), 3.45v, 6.90v, 12.27v (these are not aligned).
Which is the rationale about this divergence?
I noted also that connecting in loopback the outputs to the inputs via a TRS cable, setting the input ref level to 24dbu, I observe as ADC result:
- if the output ref level is 4dbu: the sine, plus some minor harmonics (The correct result).
- if the output ref level is 13, 19 or 24dbu: the sine plus a lot of high level harmonics, quite similar to the square wave spectrum. I return to see the normal sine spectrum only reducing the input level to -3.6db, for any input ref level.
Is this a normal behavior?
Best Regards,
Pino