User manual APOGEE ROSETTA AD

[. . . ] Rosetta AD 24-bit 2-channel A/D Converter 44. 1/48 kHz version & 44. 1/48/88. 2/96 kHz version Owner's Manual and UV22HR® License Agreement v3. 0 ­ May 2000 Firmware revision 3. 0. 0 ­ inc. Single-Wire Rosetta AD User's Guide Operational instructions written by Joe Raia. "Introduction to Digital Audio" by Julio Alvarez and Richard Elen. Production, editing and word-wrangling by Richard Elen. [. . . ] Although the A/D converter is automatically calibrated as part of the power up sequence, you can re-calibrate whenever you want to ­ just be sure to wait five minutes after power has been applied. After five minutes the converter has reached thermal equilibrium, so re-calibration at this time will yield ultimate performance. The converter is also re-calibrated each time the sample rate is changed. You can visually tell that calibration is being performed: the L/R meter displays momentarily, illuminating the middle LEDs of each segment. As the Rosetta recalibrates itself fairly frequently, you will seldom need to do it manually. Note that this calibration is only an internal calibration of the A/D converter chip and has nothing to do with the manual level settings using the L/R level trim below. L/R LEVEL TRIM Adjusts the level sensitivity of the A/D section. As discussed in the METERS description, digital and analog scales are different. The level trim pots allow you to set the Rosetta to an operating level that is convenient for your particular application. See page 18 for proper level adjustment of your Rosetta. Because of the unpredictable dynamic range of live performance, it's often desirable to have plenty of headroom to capture a performance without risking overs. In this case, you may want to set the Rosetta to ­20 or ­18dBFS. The SOFT LIMIT function will also prove to be a useful feature in live recording. Levels are usually more controlled during a mix. In this case, the Rosetta can be adjusted to ­16 to ­12 dBFS to lay down the final mix. Tracking Mixing Mastering In the mastering stage, it's often desirable to get the hottest signal on to tape. Hot transients are usually better-controlled at this stage. The converter does not need as much headroom, so it can be set to ­12dBFS. The chart on the next page shows the relationship between dBu and dBFS for the purposes of setting the levels on the Rosetta. Page 14 Rosetta AD User's Guide The Rear Panel AD INPUT Left and Right Analog inputs. The Rosetta is configured from the factory for pin 2 hot operation. To change to pin 3 hot, set DIP switch #2 to the ON position. Note: The Rosetta does not contain microphone preamplifiers, so a microphone cannot be connected directly to the AD inputs. Also, to accommodate the very high impedance outputs of guitars/basses, use a suitable preamplifier (or a "direct box") in between the Rosetta and your guitar/bass. All of the Rosetta's outputs are always active. [. . . ] Check our Web site for the latest word: http://www. apogeedigital. com/ High-Density Conversion, Word Lengths and Interconnects Page 20 Rosetta AD User's Guide Rosetta AD Specifications Analog and A/D Converter Parameter Resolution Sample Rate Input Impedance Pro Consumer Relative THD+N ­0. 1 dBFS ­20 dBFS ­60 dBFS 44. 1­48, 88. 2­96 kHz 9K 15K ­110 ­112 ­91 ­93 ­56 ­58 Value 24 ±10% dB dB dB dB dB dB (unweighted) (A-weighted) (unweighted) (A-weighted) (unweighted) (A-weighted) Units bits Parameter Professional, unbalanced Consumer, balanced Consumer, unbalanced Input Level, adjustment range Crystal Oscillator accuracy Clock Jitter, 32kHz­106 kHz Value 23 16 15 20 ±50 << 22 Units dBu dBu dBu dBu ppm psec Digital Signal Processing UV22HR Amplitude 16 bits 20 bits Over Detection ­84 dB ­108 dB 1­4 consecutive 0 dBFS readings (user-definable) Dynamic range ­60 dB, Unweighted 116 ­60 dB, A-weighted 119 Peak Spurious Component ­126 Group Delay (in passband) 34/Fs Passband Ripple ±0. 001 Digital Filter Stopband 0. 5542Fs Stop-band Attenuation 117 Channel Separation Left/right 120 Frequency Response (10 Hz­20 kHz) Gain ±0. 025 Phase < 0. 01 Common-Mode Rejection Ratio 60 Hz >> 100 1 kHz >> 80 Input Level, maximum (no gain) Professional, balanced 27 dB dB dB (max) seconds dB kHz dB dB (worst case) dB degrees dB dB dBu System 100, 120, 220, 240 vac (set internally) 115V~, 250mA, T (Slow Blow) 230V~, 125mA, T (Slow Blow) Power 15 Watts Size (w, h, d) 19 in, 1. 75 in (1U), 14. 25 in Weight 6 lb (2. 7 kg) AC line voltage Fusing 5 x 20 mm, 250V The Specifications above, and other information provided in this document, are subject to change without notice. Apogee Electronics Corporation reserves the right to make design changes without prior warning. Apogee, UV22, Soft Limit, AMBus, Clocked by Apogee, Apogee Bit-Splitting and the "96k" device are trademarks or registered trademarks of Apogee Electronics Corporation. Other trademarks are the property of their respective owners. Page 21 Rosetta AD User's Guide The Apogee Rosetta AD ­ Front & NOTE: These illustrations provide an overview of the controls and Power Switch ­ Press on, press off. [. . . ]