User manual LAVRY 3000S REV 1.4

[. . . ] Model 3000S 96kHz Digital Optimizer Operations Manual Lavry Engineering, Inc. Box 4602 Rolling Bay, Washington USA 98061 http: //www. lavryengineering. com/ E-Mail: techsupport@lavryengineering. com Revision 1. 4 November 10, 2008 Operations Manual LE3000S LIMITED WARRANTY Subject to the conditions set forth below, for one year after the original purchase date of the product, Lavry Engineering will repair the product free of charge in the United States in the event of a defect in materials or workmanship. Lavry Engineering may exchange new or rebuilt parts for defective parts. Please call the factory for an RMA number prior to shipment. [. . . ] READ LEFT/RIGHT CSBITS: When set to LEFT, the Model 3000S reads the digital audio information from the left channel (this is likely to cover most source material). The user may select the right channel. Power-Up Preset The Preset screen starts with "STORE RAM PRESET". You may store the present settings of the Model 3000S into the RAM preset (press GO) or exit the screen. Test Tones To generate a test tone, scroll to the test tone screen and set the frequency, amplitude and destination (left, right or both). To change the frequency or amplitude by large increments, hold down the CURSOR UP or CURSOR DOWN buttons. For small increments, press the CURSOR UP/DOWN repeatedly. You may change settings while the tone is generated. To stop the tone press EXIT twice (returning to the communications screen). Note: internal tone generation consists of 24 bits of resolution. The word length at the output is subject to truncation and dither settings. CNS word length is always 16 bits. 14 Tutorial LE3000S Using the Tone Generator and THD+N Features Model 3000S is an all digital machine, capable of supplying and analyzing AES/EBU and SPDIF digital audio data. While aimed at digital in/digital out applications, the use of external reference A/D and D/A converters can expand usability to include analog domain measurements (accuracy will be limited to the performance of such devices). Example A: evaluating a single digital in/digital out unit. 1. Connect model 3000S output to unit under test. Select output sample rate on main screen. Connect unit's output to Model 3000S input. Set Model 3000S for appropriate output parameters: Highest tone accuracy is achieved when unit is set to output 24 bits (Professional format). Select test tone screen, set for desired tone frequency and amplitude, and press the "GO" button. Select THD+N screen and press the "GO" button. Read results (tone frequency, amplitude and THD+N). You may now adjust "unit under test" parameters while viewing THD+N. You may go back and forth between tone generation screen and THD+N screen for testing different amplitudes at the set frequency. Selecting a new frequency requires you to press GO to re-tune the notch. Example B: optimizing multiple unit interconnections. Clearly, the microphone preamplifier resides at the front end, and the format converter at the back end. Some units may be placed in various locations in the audio chain (which is better? [. . . ] Narrow notch is required to leave noise and harmonics intact. For theoretical tones one may strive for the steepest notch possible. Real applications require full attenuation over a slightly wider frequency range to accommodate possible small jitter of both sampling clock and the tone itself. Model 3000S provides sufficient attenuation over about . 1% (allowing about 20 nsec jitter). [. . . ]