User manual APOGEE PSX-100

[. . . ] PSX-100 24-bit 2-channel 44. 1­96kHz High Density A/D-D/A Conversion System Operating Manual and UV22® License Agreement Version 3b -- July 2000 Firmware v 3. 0. 0 ­ inc. Single-Wire PSX-100 User's Manual Manual written by Doug Bell. Interconnection diagrams by Julio Alvarez. Many thanks to Roger and Brigitte Robindoré for their exhaustive proffreadign. [. . . ] Ensure that DIP switch 4 (Output level) is set correctly: OFF for +4dBu, ON for ­10 dBV Using a `tweaker' or small flathead screwdriver, rotate the left and/or right trimpot in a clockwise direction to increase gain of the D/A. It is not necessary to use a non-conductive tool. Calibrating the A/D Converter 1. Ensure that DIP switch 5 (Input level) is set correctly: OFF for +4dBu, ON for ­10 dBV. Using a `tweaker' or small flathead screwdriver, rotate left and/or right trimpot in a clockwise direction to increase gain of the A/D. It is not necessary to use a non-conductive tool. Using the AUX Output The AUX connector on the rear of the PSX-100 is an auxiliary AES output which, when available, always delivers full 24-bit resolution. It was originally designed to allow easy connection of an external, high-accuracy digital meter for mastering and monitoring applications; however it also has other uses. The AUX output is essentially the same signal as appears at the INPUT of the D/A Converter in the PSX-100. If you bear this in mind when you wish to use the AUX connector, you won't go far wrong. The AUX output is available at 88. 2/96 kHz sample rates (FAST mode), but it will only output every other sample, at 44. 1/48 kHz. This may be fine for metering, but the filtering will be wrong for accurate 44. 1/48 kHz recording and we do not recommend its use for recording purposes in FAST mode. Typical Applications Metering While using the PSX-100 A/D and D/A in Confidence Mode, for example wrapped around a digital recorder, the AUX output can be used to connect an external metering system for increased accuracy. The AUX output delivers the same signal as is present at the D/A input, so you will need to insure that a useful signal is being returned to the D/A inputs from the recorder, or this output will not work!Recording a 24-bit signal while simultaneously recording one or more 16-bit signals The AUX output is always operating at full 24-bit resolution. As a result, you can connect it to the AES input of a 24-bit recorder such as the Tascam DA-45HR while you have the main outputs set to 16-bit UV22HR ­ the latter being sent to, for example, one or more 16-bit DAT machines. It is tempting to use Confidence Mode for this purpose. . . Confidence Mode separates the A/D and D/A , and the AUX output is the same as the D/A input, so if you feed the output of the DA-45HR to the D/A input and the AUX output to the DA-45HR input you will in fact be creating a feedback loop!The solution is to use Analog Monitor Mode. In this mode, the A/D feeds both the main outputs and the AUX output; the AUX output is always 24-bit; and you can simultaneously use UV22HR on the main outputs. In addition, the D/A is fed from the A/D as well, so if you monitor the D/A output you will simply be listening to the A/D converter. Note that you will need to switch out of Analog Monitor Mode to replay the recorded signal, and you should temporarily disconnect the path from the AUX output at the same time to avoid a feedback loop when you are not in replay on the DA-45HR. You can, incidentally, use the DA-45HR locked to the PSX-100 crystal at all times, using the Word Clock output from the PSX-100. This will insure that you do not lose sync when the AUX output ceases to generate useful output in Confidence Mode (which would be the case if you were relying on the AES signal for sync). Page 20 PSX-100 User's Manual Internal Settings The following information is provided for authorized technicians only and is not intended for use by the user. Adjustment of internal settings by non-authorized persons will void the warranty. [. . . ] Other trademarks are the property of their respective owners. Page 32 The Apogee PSX-100 -- Front and rear panels Power Switch ­ push on, push off A/D Sync This button determines the Sync On power-up, the PSX performs a self-test and then recalled settings illuminate. To set the unit to its factory defaults (other than DIP switch settings), hold the OUTPUT RES button down during power-up, until the lights come on. Source for the A/D section of the PSX-100. Repeated button-presses cycle through Crystal (44. 1/88. 2 or 48/96 kHz), Word Clock, digital input or video (the latter only with sync card option). [. . . ]