Power Base-2 & 800CSL Amplifier Service Manual

Checkout Procedures

TEST 4: AC POWER DRAW

Spec: 90 Watts maximum quiescent.

Initial Conditions: Controls per standard.

Procedure: With no input signal and no load, measure AC line wattage draw. If current draw is excessive, check for high AC line voltage or high bias voltage.

TEST 5: COMMON MODE REJECTION

Spec at 100 Hz: –70 dB.

Spec at 20 kHz: –50 dB.

Initial Conditions: Controls per standard.

Procedure: No load. Inject a 0 dBu 100 Hz sine wave into each channel, one channel at a time, with inverting and non-inverting inputs shorted together. At the output measure less than –44 dBu. Inject a 0 dBu 20 kHz sine wave into each channel, one channel at a time, with inverting and non-inverting inputs shorted together. At the output measure less than –24 dBu. Adjust R921 or R1021, if necessary, to obtain the required measurements. (In older units the adjust- ments are done using N100/N200.)

TEST 6: VOLTAGE GAIN

Spec: ±3% when the Sensitivity Switch is set for 26dB gain, ±6% when the Sensitivity Switch is set for 0.775V or 1.4V sensitivity.

Initial Conditions: Controls per standard.

Procedure: No load connected. Inject a 0.775 VAC 1 kHz sine wave with the Sensitivity Switch in the 26 dB position. Measure 15.5 VAC ±0.07 VAC at the ampli- fier output. Inject a 0.775 VAC 1 kHz sine wave with the Sensitivity Switch in the 0.775V position. Measure 50.6 VAC ±1.5 VAC at the amplifier output. Inject a 1.4 VAC 1 kHz sine wave with the Sensitivity Switch in the 1.4V position. Measure 50.6 VAC ±1.5 VAC at the amplifier output. Return the Sensitivity Switch to the 26 dB position.

TEST 7: PHASE RESPONSE

Spec: ±10° at 1 Watt.

Initial Conditions: Controls per standard, 8 ohm load on each channel.

Procedure: Inject a 1 kHz sine wave and adjust for 1 Watt output (2.8 VAC). Check input and output signals against each other, input and output signals must be within 10° of each other.

TEST 8: LEVEL CONTROLS

Spec: Level controlled by level controls.

Initial Conditions: Controls per standard.

Procedure: No Load. Inject a 1 kHz sine wave. With level controls fully clockwise you should see full gain. As controls are rotated counterclockwise, observe similar gain reduction in each channel. When com- plete, return level controls to fully clockwise position.

TEST 9: CURRENT LIMIT

Spec: Current Limit at 20 ±2 Amps

Initial Conditions: Controls per standard.

Procedure: Load each channel to 1 Ohm. Inject a 1 kHz differentiated (or 10% duty cycle) square wave and increase output level until current limit occurs. Current limit should occur at 20 ±2 Amps. Observe clean (no oscillations) current clipping.

TEST 10: SLEW RATE & 10 KHZ SQUARE WAVE

Spec: >13V/µS.

Initial Conditions: Controls per standard.

Procedure: Load each channel to 8 ohms. Inject a 10 kHz square wave to obtain 40 volts peak-to-peak at each output. Observe the slope of the square wave. It should typically measure 17 to 25 V/µS. Also, the square wave must not include overshoot, ringing, or any type of oscillation.

TEST 11: CROSSTALK

Spec: <33 mVAC at 20 kHz.

Initial Conditions: Controls per standard. Short input of channel not driven.

Procedure: 8 ohm load on each channel. Inject a 20 kHz sine wave into the Channel 1 input and increase output level to 46.9 VAC. Measure less than 40 mVAC at the output of Channel 2. Inject a 20 kHz sine wave into the Channel 2 input and increase output level to 46.9 VAC. Measure less than 40 mVAC at the output of Channel 1.

TEST 12: OUTPUT POWER

Spec at 8 Ohm Stereo: 320W at 0.1% THD.

Spec at 4 Ohm Stereo: 400W at 0.1% THD.

Initial Conditions: Controls per standard.

Procedure: Load each channel to 8 ohms. Inject a 1 kHz sine wave and measure at least 50.6 VAC at the output of each channel. Load each channel to 4 ohms. Inject a 1 kHz sine wave and measure at least 40.0 VAC. All power measurements must be at less than 0.1% THD.

TEST 13: REACTIVE LOADS

Spec: No oscillations. Safe with all types of loads.

Initial Conditions: Controls per standard.

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Crown Audio 800CSL Test 4 AC Power Draw, Test 5 Common Mode Rejection, Test 6 Voltage Gain, Test 7 Phase Response
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800CSL specifications

Crown Audio has long been a respected name in professional audio equipment, and the 800CSL amplifiers are a testament to their unwavering commitment to quality and performance. Designed for professional sound reinforcement applications, the Crown 800CSL offers an impressive blend of power, reliability, and versatility, making it a popular choice among audio engineers and event coordinators.

At the heart of the Crown 800CSL is its robust power output. This amplifier delivers an impressive 800 watts per channel at 4 ohms, ensuring that it can drive even the most demanding speakers with ease. It features a Class D design, which not only maximizes efficiency, allowing for more power with less heat generation, but also contributes to a lightweight chassis that is easy to transport and install. This makes the 800CSL a versatile option for both permanent installations and mobile events.

One of the key technologies employed in the Crown 800CSL is its comprehensive built-in protection circuitry. This includes advanced short circuit protection, over-temperature protection, and current limiting. Such features ensure that the amplifier operates reliably in challenging conditions, reducing the risk of damage to both the amplifier and the connected speakers. The inclusion of a low-frequency filter further enhances performance, providing clean, powerful bass without distortion.

The Crown 800CSL also offers a range of connectivity options, including XLR and ¼-inch inputs, making it compatible with a wide variety of audio sources. This flexibility, combined with user-friendly front panel controls, allows audio professionals to set up and adjust the system quickly and efficiently.

Additionally, the amplifier features a robust and compact design with a lightweight aluminum chassis. This not only contributes to its portability but also aids in heat dissipation, further enhancing performance during prolonged use. The included handles on the chassis make it easy to transport the unit between gigs, while its durable components ensure longevity.

In summary, the Crown Audio 800CSL stands out for its power, efficiency, and reliability. From its Class D amplification technology to its comprehensive protection features, this amplifier is designed to meet the needs of professionals in the audio industry. Whether for concerts, events, or installations, the 800CSL is poised to deliver exceptional sound quality and performance, making it a valuable addition to any audio toolkit.
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