Fidelitone JT-322 Phono Cartridge
A new magnetic phono cartridge designed for stereo and CD-4 four-channel applications has been brought out by Fidelitone as the Model JT-322. The user-replaceable stylus assembly of the cartridge has a nude diamond tip ground to a modified elliptical configuration that is suitable for CD-4 use. Frequency response is 10 to 45,000 Hz and recommended tracking force ranges from 1.2 to 2 grams. The JT-322 has an output of 2.5 millivolts for a re corded velocity of 5 centimeters per second.
The outputs of the two channels are balanced within I dB, and stereo separation exceeds 25 dB at 1,000 Hz. A resistive load of 100,000 ohms at the phono preamplifier is recommended for use with the cartridge.
The JT-322 has an effective tip mass of 0.55 milligram and a rated dynamic compliance of 10 x 10^-6 centimeters per dyne. Static compliance is 25 x 10-6 centimeters per dyne. The cartridge weighs 4.8 grams. Price: $54.95.
AR Speaker Stands
In response to considerable demand, Acoustic Research now offers attractively styled speaker stands designed especially for the AR-107 and AR-11. The all-metal stands are finished in matte black and are approximately 14 inches wide, 10 3/4 inches deep, and 12 inches high. Presumably they are usable with other speaker systems that have dimensions similar to the AR models. Price: $39.95 per pair.
Infinity Servo-Statik 1A Stereo Speaker System
One of the most elaborate and expensive speaker systems in the world is Infinity Systems' Servo-Statik 1A, which supersedes that manufacturer's Servo-Statik 1. Essentially the system is composed of three pieces; two electrostatic mid- and high-frequency "screens" for the left and right channels and a single dynamic low-frequency module that serves as a common-bass source. A fourth unit-an electronic crossover-completes the ensemble.
The large electrostatic screens-59 1/2 x 35 1/2 inches, with a depth of 8 inches-contain six mid-range and seven smaller high-frequency panels each. Five of the high-frequency panels are arranged in a vertical line down the center of the screen to enhance lateral dispersion. In the base of each screen is a power supply to energize the electrostatic elements and transformers through which the elements are driven, presenting nominal impedances of 16 (mid-range) and 8 (high-frequency) ohms to the driving amplifiers. Two amplifier channels per screen are required to operate the system.
Recommended amplifier-power ranges are 100 to 250 watts per channel for the mid-range elements and 35 to 125 watts per channel for the high-frequency panels. The electronic crossover divides the drive signal to these amplifiers at 2,000 Hz, with a 6-dB-per-octave crossover rate.
Below 70 Hz the output of the Servo-Statik IA is transferred to the bass module, which has its own built-in 150-watt amplifier. The module consists of an 18-inch cone woofer in a sealed enclosure 22 inches square and 19 inches high, supported by a 2 1/2-inch base. A motional-feedback system is employed that senses the movements of the woofer's voice coil and derives from them a "correction" signal that is returned to the input of the amplifier, thus compensating for any motional "errors" by altering the woofer drive signal.
Rated frequency response of the system is 10 to 30,000 Hz ±2 dB. At a distance of 1 meter the system can achieve peak sound-pressure levels of 114 dB. The electronic crossover has a maximum output of 7 volts rms, with distortion under 0.01 percent at 6 volts. The crossover is entirely made up of high-voltage FET circuits with an input impedance of 35,000 ohms. Controls on the crossover unit permit adjustment of the high- and low-frequency output of the systems over a 10-dB range; mid-range levels are fixed. The components of the Servo-Statik IA system have rosewood veneer finishes with black grilles.
Cloth is used for the woofer grille, and thin reticulated foam for the electrostatic screens.
Fore-and-aft supports permit free-standing installation of the screens. Price of the complete system: $4,000.
Tandberg TR 1040 Stereo FM Receiver
Occupying the lower price range in Tandberg's line of stereo receivers is the Model TR 1040, which provides 40 watts of continuous power per channel into 8-ohm loads at any frequency from 20 to 20,000 Hz with less than 0.2 percent harmonic or intermodulation distortion. Signal-to-noise ratios are 82 dB for the high-level inputs and 68 dB for the phono inputs. An unusual feature of the FM-only receiver is the array of five tuning controls concealed behind a hinged section of the front panel. These are used to pre-tune up to five FM stations of the user's choice so that any can be selected instantly at the press of a push-button. The hinged section also hides switches for such functions as mono/stereo mode, loudness compensation, a low-frequency filter (-12 dB per octave below 70 Hz) and two high-frequency filters (-6 or-12 dB per octave above 8,000 Hz).
For its basic controls, the TR 1040 has separate concentrically mounted bass and treble adjustments for each channel, a speaker se lector for two pairs of speakers, plus volume and balance controls and a tuning knob. Push buttons select the program source (two inputs for high-level external sources are provided), operate the tape-monitor circuit, and introduce interstation-noise muting, automatic frequency control (AFC), and mono reception for the FM section. There are tuning meters for signal strength and channel center, a stereo headphone jack, and a front-panel tape-dubbing jack. On the rear panel, besides the various connectors, there are level adjustments for the input jacks.
Performance specifications for the FM tuner section include an IHF usable sensitivity of 2 microvolts, a 50-dB quieting sensitivity of 3.5 microvolts, and a capture ratio of 0.9 dB.
Alternate-channel selectivity is 80 dB and spurious-response rejection is greater than 95 dB. Between 100 and 10,000 Hz the stereo separation exceeds 40 dB. Harmonic distortion is 0.2 percent for mono, 0.3 percent for stereo. Overall dimensions of the receiver are approximately 171/2 x 51/4 x 13 inches. The wood cabinet supplied is finished in walnut veneers. Price: $599.
Heathkit "Modulus" Audio Center "Modulus- is the Heath Company's approach to maximum flexibility and growth potential in an audio system. At the heart of the concept is the AN-2016 control unit (center), which is actually a four-channel tuner-preamplifier with digital display of the AM or FM broadcast frequency being received. For power amplification, Heath offers a choice of two stereo modules with styling to match the AN-2016: the AA-1505 (35 watts per channel) and AA-1506 (60 watts per channel).
Alternatively, other brands or models of power amplifiers may be used with the AN-2016 (the Heath power-amplifier modules may also be used with any other preamplifier/control unit).
A principal feature of the AN-2016 is the provision for optional circuit modules that plug into special sockets within the unit's chassis. At present, three such modules are offered-for Dolbyized FM, CD-4 demodulation, and SQ decoding (the SQ decoder is of the advanced wave-matching/variable-blend type). Modules for other matrix systems may become available in the future. In addition, there is space within the AN-2016 chassis for add-on four-channel FM circuitry should a system for such broadcasts ever be approved.
The Heath AN-2016 will function as a tuner and control center for a modest stereo system or-with the addition of another stereo power amplifier and the appropriate optional circuit modules-as an elaborate four-channel preamplifier-tuner that can handle almost all matrix and discrete four-channel programs.
Its main controls are independent level adjustments for each channel, master volume control, separate bass and treble controls for the front and rear channels, and a tuning knob. Electrical balance of the system is facilitated by four peak-reading output-level meters that are calibrated over a range of 40 dB.
There are also tuning meters for signal strength and center of channel. Pushbuttons that light when depressed select the input and perform all other control functions, such as tone-control bypass, tape monitoring, loudness compensation, high- and low-cut filtering, and FM interstation-noise muting. Mode (mono, stereo, four-channel, etc.) is also pushbutton controlled. The AN-2016 contains headphone amplifiers with output jacks for front and rear channels on the front panel, along with four-channel tape-dubbing jacks that duplicate identical facilities in the rear.
The unit has separate inputs for stereo and CD-4 phono cartridges, oscilloscope outputs, and four a.c. convenience outlets among its other connectors.
The AN-2016's preamplifier section has a frequency response of 10 to 30,000 Hz +0, -0.05 dB, with a rated output of 1.5 volts, for which harmonic and intermodulation distortion are both 0.05 percent. Signal-to-noise ratios are 80 dB for the phono and high-level inputs. The high and low filters, effective above 7,000 and below 30 Hz, respectively, have 12-dB-per-octave slopes. Usable sensitivity for the FM section is 1.7 microvolts, and 50-dB quieting sensitivity is 3.5 microvolts for mono, 35 microvolts for stereo.
Other FM specifications include: 1.3-dB cap ture ratio; 68-dB AM suppression; 100-dB alternate-channel selectivity; 90-dB spurious-response rejection; and 100-dB i.f. rejection.
Frequency response is 20 to 15,000 Hz ±1 dB with harmonic distortion of less than 0.3 percent. The ultimate FM signal-to-noise ratio is 68 dB. The AN-2016's AM section has an FET front end and provides a frequency response of 25 to 7,000 Hz ±3 dB.
Power outputs for the AA-1505 and AA-1506 stereo power amplifiers are 35 and 60 watts per channel continuous, respectively, into 8 ohms at any frequency from 20 to 20,000 Hz. Harmonic and intermodulation distortion are both under 0.1 percent, and signal-to-noise ratios for both units are 95 dB.
Input sensitivity is 1.5 volts for full output.
Input impedance is greater than 15,000 ohms.
The three Heath Modulus components are available only as kits. During assembly, the meters of the AN-2016 are used as test instruments for checking and adjusting internal circuitry. Dimensions of the AN-2016 are 19 x 6 1/2 x 14 1/2 inches; the power-amplifier modules both measure approximately 8 x 5 3/8 x 14 2/3 inches. Integral plastic cabinets are pro vided with all Modulus components. Prices: AN-2016, $599.95; AA-1505, $159.95; AA-I506, $179.95.
Optional modules for installation within the AN-2016 are $39.95 for the Dolby FM circuit, $49.95 for the SQ decoder, and $79.95 for the CD-4 demodulator.
PUBLISHER'S NOTICE: Recent fluctuations in the value of the dollar will have an effect on the price of merchandise imported into this country. So, please be aware that the prices quoted in this issue may be subject to change.
------------
Also see: