The PSX-100 is equipped with a feature called "Loop Back Muting" which prevents any digital feedback from happening. Any mirrored output from the digital source being fed into the PSX-100 is muted automatically and can be defeated. To defeat this mode press Dig Copy once to enter the digital copy mode. Now press and hold the Dig Copy button until it starts flashing.

To use the PSX-100 at higher sample rates, press and hold the A/D sync button until the x2Fs light is on. At this point 44.1 equals 88.2 kHz and 48 equals 96 Khz.

At higher sample rates, the UV22 process is turned off because 16-bit audio is only compatible with 44.1 or 48 kHz sample rates.

Only the AES and S/PDIF digital outputs can operate at higher sample rates. The optical ADAT outputs are not equipped to handle 88.2 or 96 kHz.

If there is no digital input attached to the PSX-100 then the unit will indicate this via the error light. This is a normal operation of the unit. To clear the error light, attach a digital input and choose the appropriate input via the D/A sync.

Yes, the PSX-100 can be modified to Single Wire operation. The upgrade cost is $399.00 and the unit must be sent to Apogee for this upgrade.

The PSX-100 has can be calibrated to a level between -20 and -11 dBFS. To enter calibration mode, press and hold the SoftLimit button until it begins to flash. At that point, the meters are reflecting the "zoom meter" mode with the bottom LED corresponding to -20 and the top LED to -11 dBFS. Insert a +4 analog tone into the analog inputs and press the Meter mode to reflect A/D metering. By default, the level of calibration from the factory is -16 dBFS. To calibrate for a -12 dBFS, turn the A/D calibration trimpots. As the level increases one LED, which equals one dBFS, the over light will turn on indicating you have achieved the next level up in dBFS. Each LED you light up will cause the over light to come on, and as you increase the gain, the over LED will go off until the next LED is lit up. When you get to the desired level, stop as soon as the over LED lights up. On the meter, -10 equals -16 dBFS, -6 equals -14 dBFS, and -2 equals -12 dBFS. For the D/A calibration, a digital signal equal to the A/D calibration must be sent to one of the digital inputs. Put the PSX-100 into the D/A metering mode. Take the analog outputs of the PSX-100 and feed it into a device with analog metering. Since digital level can not be changed, only the analog output is being reflected. Turn the D/A trimpots so that the external analog metering hits 0.