EQ-2_Test_Spec 电路图.pdf

TEST SPCIFICA TION: TL Audio EO2 PARAMETRIC VALVE EOUALISER. Issue 1: 19th Januarv 1996. Tolerance on inputs +/-O.2dB, outputs +/-ldB, unless stated otherwise. 1. MAINS VOLTAGE: Set to 240V. 2. GROUND CONTINUITY: Limit 0.01 ohms. 2.1 Measure the resistance between the ground pin of the IEC inlet to the chassis ground screw. 3. VISUAL INSPECnON: Inspect the unit, paying particular attention to the following items: 3.1 - the orientation of power supply diodes and capacitors, 3.2 - the orientation and seating of ICs, 3.3 - all mains wiring, 3.4 - check the solder side of the PCB for unsoldered joints and solder splashes, 3.5 . - the quality of external paint and silk screening, 3.6 - check all knobs and switches operate freely and are uniformly spaced from the panel, 3.7 - all XLR connectors are locked, 3.8 - LED alignment with front panel. 4. SWITCH ON: 4.1 Check for any sign of component stress or overheating. 4.2 Operate all push switches and check the operation and colour off all LEOs. Tests 5 to 10 should be performed on each channel: 5. PHANTOM POWER: +48V. Equaliser: 48V On, measure on pins 2 and 3 ofMic input socket, using the test fixture. ( , RadioFans.CN 收音机爱 好者资料库 6. INPUTS: 6.1 LINE INPUT: Output OdBu. A2: 1KHz, sine, OdBu, 22Hz-22KHz filter. EqWtliser: Input to Line XLR, Switch to Line Input, Input and Output Gain centre detent, LF and HF Cut off, EQ out. Adjust RV32 for OdBu output on Channel A (from underneath the PCB), and RVI7 for OdBu output on Channel B. 6.2 EQUALISER IN: Output OdBu. Switch the EqWtliser in with all controls central, and all bands on. Check the output changes by less than O.5dB. 6.3 FREQUENCY RESPONSE: -ldB 20Hz to 40KHz. A2: Sweep, filters off. 6.4 OUTPUT BALANCE: Adjust using the test fixture. 6.5 OUTPUT LEVEL SWITCH: Output -14dBu. Equaliser: OIP Level switch -IOdBu. Return switch to +4dBu position after test 6.6 UNBALANCED INPUT AND OUTPUT: Output 0 +/-2dBu. Equaiiser: Rear panel jack input and output. 6.7 AUX INPUT: A2: Output level -20dBu. Equaliser: Input to front panel Auxjack, output via XLR, Input and Output Gain centre. Switch to Low Gain, check output -17 dBu. Switch to High Gain, check output + 3dBu. 6.8 MIC INPUT: Output OdBu. Equaliser: Mic Input, Input Gain Max, EQ out, EQ flat, Output Gain (Master) centre. A2: 1KHz, Sine, -60dBu, 22-22KHz Filter, Meter. 6.9 MIC INPUT NOISE: Limit -67dBu (EIN = -127dBu). Equaiiser: Disconnect input and replace with 150R termination. J RadioFans.CN 收音机爱 好者资料库 . 7. HUM AND NOISE: -78dBu. A2: OdBu, Output Mute, 22Hz-22KHz. Equaliser: Line XLR input, switch to Line input, EQ out, Input and Output Gain centre. Switch EQ in, all bands on with all controls centred. Check noise limit -75dBu. 8. DISTORllON: Limit 1 %. A2: 22-22K Filter out, THO, Output On. 9. LF AND HF CUT RESPONSE: A2: Level. Equaliser: LF and HF Cut in, frequency controls centre. Sweep the A2, and check for a bandpass response -3dB at 150Hz and 5.5KHz. Tolerance on frequencies +/-10%. Switch the LF and HF Cut off. 10. EQ RESPONSE: For each band: Set the CutlBoost, Frequency and Q controls fully anti-<:lockwise. Sweep the A2 (20Hz-40KHz) and check against the reference plot. (j- Set the Cut/Boost, Frequency and Q controls fully clockwise. Sweep the A2 (20Hz-40KHz) and check against the reference plot. Return the controls to their centre positions. Note: For channel B, repeat in stereo mode, using the Channel A controls. 11. SOAK TEST. 12. AUDIO/QA TEST. RadioFans.CN 收音机爱 好者资料库