User manual APOGEE MINI-DAC

[. . . ] 2-Channel 24 bit/192kHz D/A Converter (with optional USB) User's Guide v1. 0 - June 2003 2-Channel 24 bit/192kHz D/A Converter (with optional USB) User's Guide v1. 0 - June 2003 Mini-DAC ­ User's Guide Warnings FCC warning This equipment has been tested and found to comply with the limits for a Class A digital device, pursuant to Part 15 of the FCC rules. These limits are designed to provide reasonable protection against harmful interference when operated in a commercial environment. This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with the instruction manual, may cause harmful interference to radio communications. Operation of this equipment in a residential area is likely to cause harmful interference, in which case the user will be required to take whatever measures necessary to correct the interference at his own expense. Copyright Notice The Apogee Mini-DAC is a computer-based device, and as such contains and uses software in ROMs. [. . . ] 1 connects his headphones to the front panel Output, while performer no. 2 gets his headphone feed from an external headphone amp connected to the 1/8" LINE OUT (whose jumper is set to FIX). While recording, the POWER switch is set to ; the monitor speakers are muted (to avoid bleed into the microphones), performer no. 1 connects his headphone to the Output and adjusts his listening level with the front panel LEVEL control, and performer no. 2 connects his external headphone amp to the 1/8" LINE OUT, allowing him to control his listening level independently. If both performers are using similar headphones and can agree on listening levels (which we all know is unlikely!), the 1/8" LINE OUT may be used directly as a second headphone output. Set the 1/8" Out jumpers to VAR, and control both headphone sends with the front panel LEVEL knob. During playback, the POWER switch is set to ALL, thereby activating the XLR outputs feeding the monitor speakers, in addition to the other two outputs. 4 5 7 3) SIGNAL indicators ­ The brightness of these LEDs displays the left (L) and right (R) signal level of the selected INPUT SOURCE. The LEDs begin to illuminate at a level of ­30 dBFs and are at their brightest at 0 dBFs. 4) LOCK ­ These LEDs indicate the Lock status of Mini-DAC's dual stage clock. Two levels of lock precision are displayed, W(ide) and N(arrow). 5) POWER ­ The POWER switch not only turns the unit on and off, but also selectively activates analog outputs according to the position of the switch. FIGURE 1 displays the outputs activated at each switch position. 6)LEVEL ­ This knob always controls the Output level; the knob also controls the XLR ANALOG and 1/8" LINE OUT output levels when each output's internal jumper is set to VAR. 7) ­ This headphone output utilizes a discrete, high slew rate amplifier stage able to effortlessly drive modern low impedance headphones. As the amplifier can generate sound levels potentially damaging to hearing, please reduce the LEVEL knob before connecting headphones. POWER SWITCH POSITIONS ALL Output On LEVEL knob Active Muted Output On Trimpots Active Muted Output On Fixed Output Level Output On LEVEL knob Active Output On LEVEL knob Active Trimpots Active Output On Trimpots Active Output On LEVEL knob Active Output On Fixed Output Level Ouput O U T P U T S XLR Output (XLR OUT jumper on VAR) XLR Output (XLR OUT jumper on TRIM) 1/8" Output (1/8" OUT jumper on VAR) 1/8" Output (1/8" OUT jumper on FIX) FIGURE 1 For more information on configuration of the XLR and 1/8" Outputs, see the section of this manual entitled "INTERNAL ADJUSTMENTS". APOGEE ELECTRONICS 5 Mini-DAC ­ User's Guide Connections on the Rear Panel 2 5 1 3 4 6 7 1) 2) 3) POWER input ­ The DC input accepts a range of voltages between 6 and 14 volts DC. The power supply employed must be capable of delivering 1. 25 amps of current within the specified range. S/PDIF input ­ This RCA (Cinch) connector accepts S/PDIF Coaxial Input. OPTICAL input ­ This Toslink connector accepts Optical input in the format selected by the front panel INPUT SELECT knob. Please see the section entitled "About Digital Audio Formats" for detailed information on the formats provided. AES IN ­ This Sub-D connector accept AES/EBU input in the format selected by the front panel AES parameter, using the supplied Sub-D 9 pin to 2 female XLR adaptor cable. When INPUT SELECT is set to AES 1 or 2, each connection accepts a discrete stereo input; when INPUT SELECT is set to AES DOUBLE, both connections used in conjunction accept one stereo input. Please see the section of this manual entitled "Working with USB" for more details concerning operation of the MiniDAC with USB devices. LINE OUT ­ This 1/8" stereo connector provides an unbalanced analog output at a maximum output level of +7 dBV, for use with ­10dBV equipment or as a second headphone output. [. . . ] For example, AES Double Wire format can carry only 1 channel of audio per connection, uses XLR connectors, is used only with sample rates between 88. 2 and 192 kHz, and transmits data at half the sample rate ­ i. e. , bits travel at 48kHz when transmitting a 96kHz digital audio signal. 12 APOGEE ELECTRONICS Mini-DAC ­ User's Guide Internal Adjustments Jumpers P4 & P9 ­ These jumpers are used to configure the XLR ANALOG OUTPUTS. · When jumpers are installed between the two pins labeled VAR, the output level is controlled by the Front Panel LEVEL knob and trimpots R 45 and R 71 (factory default). · When jumpers are installed between the two pins labeled TRIM, the output level is controlled by trimpots R 45 and R 71 only. Trimpots R45 & R71 - These trimpots modify the XLR ANALOG OUTPUT level regardless of the position of jumpers P4 and P9. [. . . ]