The model AA-1 Audio Analyzer is almost a complete laboratory in itself, in that it combines the function of an AC VTVM, a wattmeter, and an IM analyzer. Combining these instruments into one compact package allows making a very thorough analysis of audio equipment without the necessity of cluttering the work bench with various instruments and sometimes a bewildering number of test leads. Power output, noise, gain, overload and intermodulation characteristics can be determined quickly and accurately using the two sets of test leads furnished and the flexible switching system incorporated in the analyzer. Non-inductive load impedances of 4, 8, 16 and 600 ohms are built-in and are switch-selected for the desired resistance. A high impedance position is also provided for stage-to-stage and other high impedance circuit analysis.
Unique circuitry is used in the AC VTVM portion of this instrument to secure improved performance. Employs a cascode type input stage for high gain at low noise levels, thus improving meter accuracy at all voltage readings. The VTVM circuit can be used for measuring noise, frequency response, output, gain, power supply ripple, etc. The built-in wattmeter allows simple measurements of power output with either internal or external loads. DBM scales are also provided so that the db gain or loss may be noted quickly. Circuit and meter ballistics are such that the instrument makes an excellent level monitor for recording and program feed purposes. High and low frequency generators for IM measurements are built in so that no additional equipment is necessary for intermodulation distortion testing. IM tests may be made at the amplifier output and at individual high impedance stages.
All basic operations of the instrument can be accomplished by connecting the output leads to an amplifier input, and the input leads to the amplifier output, and rotating the function selector switch through all of the available positions. A glance at the specifications will quickly show the many functions and features available.
The careful design of this instrument allows a maximum in performance, flexibility and utility. High quality components are clearly marked for easy identification. The instruction manual contains a complete circuit description plus information on its use and applications. The AA-1 is attractively styled with all functions of the controls clearly indicated. If you are active in the design or repair of audio equipment you will find the AA-1 a welcome friend indeed.
Specifications—Frequency Response: AC VTVM—10 cycles to 100 kc ± 1 db. Wattmeter—10 cycles to 50 kc ± 1 db. IM Analyzer High Pass Filter—2000 cps to 12000 cps. IM Analyzer Low Pass Filter—10 cps to 600 cps. Range: AC VTVM—0.01, 0.03, 0.1, 0.3, 1, 3, 10, 30, 100, 300 V. RMS full scale. DBM— -40, -30, -20, -10, 0, +10, +20, +30, +40, +50. Reads from -65 to +52 DBM. Wattmeter—15 mw, 1.5 mw, 15 mw, 150 mw, 1.5 w, 15 w, 150 w full scale. Maximum continuous power 25 watts, intermittent power to 50 watts. IM Analyzer—1%, 3%, 10%, 30%, 100% full scale. Input Impedance: AC VTVM—1 megohm or 4, 8, 16 or 600 ohms switch selected. IM Analyzer—1 megohm or 4, 8, 12 or 600 ohms switch selected. Wattmeter—4, 8, 16 or 600 ohms internal load, 10,000 ohms across ext. load. Output Impedance: Low and High Frequency Output—3000 ohms (600 ohms when shunted with a 750 ohm resistor). Internal Generator Frequencies: Low Frequency—60 cycles. High Frequency—Approximately 6 kc. Accuracy: AC VTVM and Wattmeter—Within 5% of full scale. IM Analyzer—Within 10% of full scale. Power Requirements: 115-125 VAC, 50-60 cycles, 20 watts.Dimensions: 13" wide x 8½" high x 7" deep. Shipping Weight: 13 lbs.