Apogee AD-16x Calibration Drift

[gg85]

Hey guys, just wondering if anyone might have any experience with AD-16x calibration and why mine doesn't seem to keep it's cal that well. The DA-16x seems to be holding it cal but over a few days the AD has drifted a little, sometimes .5db. After a while it can be over 1db out on a few channels. When I'm going from DA-16x to a Burl B2 ADC the level is solid and coming back in at -16 but with the Apogee it just doesn't hold near as well. I'm recalibrating a few times a week to keep it as close to -16 as I can.

I know these units are pretty old now, just seeing if someone might know what causes this and if it's something I might be able to fix.

Thanks,
George

 

[scott2000]

Got ch 1&2 outputting half the signal level on a DA-16x....600mV ish.....should be +4dBu other channels seem fine so far.... not sure where to start poking around...

The DA-16X uses Apogee’s newly developed electronically balanced line drivers, able to simulate true transformer behavior. The circuitry is an ultra low output impedance, high current driver, capable of running levels up to 26 dBu to the most complex or low impedance loads. Recording studios utilizing vintage audio-equipment will find this particularly valuable. Ultimately, the output performance of the DA-16X achieves perfect symmetry when used in balanced mode (even with an unsymmetrical load) and no increased distortion when used unbalanced.