Equipment information

JBL 5233 Amplifier
Manufacturer:
Model:
5233
Date:
1978
Category:
Group:
Description:
Electronic Frequency Dividing Networks

Information

Owner’s Instructions The 5233 and 5234 are designed for use with studio monitor or sound reinforcement loudspeaker systems where bi-amplification or tri-amplification is desirable. The 5233 (single channel) and 5234 (dual channel) feature differential high impedance inputs, unity gain in the passband, and unbalanced low impedance outputs. The 5233 will provide a single channel Crossover. The 5234 provides two separate channels with independent Crossover action (as in a stereo installation). The power switch and pilot light for the unit and a high frequency level control for each channel are located on the front panel for easy access. The Crossover frequency at which each channel is operating is indicated through a front panel window. A voltage change switch is located on the rear panel. Either model can be mounted in one EIA standard rack space. Crossover cards are available for most commonly used frequencies. Filter slopes are 12 dB or 18 dB per octave with high and low frequency output attenuated 3 dB at the Crossover point. Cards are also available with the specific Crossover characteristics required for the JBL 4343 or 4350 bi-amplified studio monitors. In addition, blank cards can be obtained for construction of Crossover networks for other frequencies. Installation The electronic frequency dividing network receives the program signal from a line level source preamplifier, studio console, or portable mixer-and separates the signal into high and low frequency bands. Outputs from the network feed the appropriate power amplifiers, which in turn drive their respective loudspeaker system components. Input connections may be balanced or unbalanced, output con- nections are unbalanced; shielded cable is required. If output cable lengths are greater than 4.5 to 6 m (15 to 20 ft), isolation transformers (600 Cl 600 Q) are recommended at each output to reduce the possibility of radio frequency interference or hum. The outputs can deliver +18 dB (6.2 V into 600 Q) and will drive the line inputs of conventional amplifiers. Two or more power amplifiers can be driven from each output. The 5234 dual channel network can be used to tri-amplify a loudspeaker system by connecting the low frequency output of channel 2 to the input of channel 1. (Twist two unshielded wires together or use shielded cable for this connection.) The channel 1-outputs can then be used to drive the midrange and low frequency amplifiers. Typical installations are diagrammed in Figure 1. Whenever a midrange or high frequency driver is connected directly to a power amplifier, a series capacitor is recommended to attenuate unwanted low frequency “on-off" switching transient signals which can damage the driver. It is possible to construct a system using an electronic low frequency transition and a conventional passive network for the midrange or high frequency Crossover. The JBL 4350 Studio Monitor, diagrammed in Figure 2, is such a system. If a pair of 4350s are to be used, a single 5234 can accommodate both systems. Note that the passive, high level frequency dividing networks used in all JBL studio monitors designed for bi-amplification already incorporate the required attenuation capacitors to protect the midrange and high frequency drivers.

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Service Manual
Manual Type:
Service Manual
Pages:
16
Size:
7.04 Mbytes (7386265 Bytes)
Language:
english
Revision:
Manual-ID:
Date:
1978 01 01
Quality:
Scanned document, all readable.
Upload date:
2017 09 24
MD5:
ff6227e221ed65e5d6d3646a72fb8c0d
Downloads:
1200

Information

Installation and Service Manual

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