Twin powered AM/FM and Stereo FM solid state receiver
Harman/Kardon engineering skill has been incorporated into a superb receiver; the 930. we say with full confidence that the Harman/Kardon 930 creates a new standard for stereo high fidelity receivers
The twin-powered amplifier section
The Harman/Kardon 930 is the first receiver in the world with two totally separate power supplies. Several manufacturers imply that their receivers incorporate two power supplies in reality, they employ a single supply with negative and positive voltages. The 930 also employs negative and positive voltages But, in addition, each chabnnel is completely isolated and has its own power transformer and electrolytics. Each channel has its own regulated voltages to permit that channel to respond to full RMS power output without being affected by the other channel. Thus, the 930 guaranteed flawless performance regardless of how much power the amplifier is called upon to deliver.
Power rating
Power rating is one of the most abused specifications in high fidelity. Despite the existance of standard procedures, it is often the manufacturer who determines the conditions under which power is rated. Harman/Kardon engineers believe that Continuous power, calculated from TMS voltage measurements, is the only meaningful way to rate power output.
But such a rating is still insufficient. Firstly, Continuous power output must be measured with both channels driven simultaneously at a specified distortion level. Secondly, the load impedance and power line voltage at which the measurement was taken must be given.
Finally, the measurements should be made across the entire frequency spectrum, rather than at 1,000 Hz. In short, the conditions under which the receiver is measured should be similar to those under which it will be used.
The preamplifier.
The 930's preamplifier delivers a signal so pure that its distortion cannot be measured with any degree of accuracy, even on the most sophisticated analysers. Only professional separate components can match this preamplifier section's hum noise and frequency response specifications.
One of the most important specifications of any high quality preamplifier is that of phono overload. The 930 specification is equal to or better than that of any receiver available. The 930 preamplifier can handle an input signal 50 times greater than that required to drive it to full output. This makes it virtually impossible to distort the preamplifier output.
What is more, absolute accuracy in playing back stereo records is assured as a result of the extremely tight tolerance of the RIAA playback curve.
The Tuner section
The tuner section of the 930 is a worthy companion to its superb amplifier. It employs high gain integrated circuits and matched ceramic filters. The result is hard limiting and excellent alternate channel selectivity. Hard limiting permits the detection of all FM stations - weak or strong - with equal clarity. Noise and distortion are completely eliminated. What's more, the excellent capture ratio and alternate channel selectivity mean that even weak stations will emerge free of interference from adjacent strong stations, impulse noise, and multipath interference. Precise alignment of the IF section is "frozen" into the circuitry and never requires realignment.
An FET front end, coupled with a four ganged tuning capacitor assures maximum sensitivity. The ultra-linear ratio detector delivers a precision composite signal to the multiplex section. Thus, even the highest frequencies are free of distortion.
The multiplex section employs balanced integrated circuitry which completely cancels SCA interference and high frequency phase distortion. It maintains maximum stereo separation throughout the entire audio range.
The FM muting circuit is of unique design which provides a smooth-as-velvet muting transition. In reality, it's simply go, no-go muting.
In short, the tuner section of the 930 assures unsurpassed sensitivity and selectivity and achieves a degree of excellence on a par with the receiver's amplifier.
Specifications
Amplifier Section
Power Output: 45/45 watts, RMS , both channels driven into an 8 Ω load, from 20 - 20,000 Hz at less than 0,5% T.H.D. 120 volts, 50/60 Hz AC (same specification applies to 220 volts, 50 Hz model)
Power Bandwidth: From less than 10 Hz to beyond 40 kHz at less than 0,4% T.H.D. into 8 Ω , both channels driven simultaneously.
Total Harmonic Distortion : less than 0,5% at 45/45 watts. Power output into 8 Ω , 20 - 20,000 Hz, both channels driven simultaneously (typically runs 0,2% from 20 - 20,000)
00,7% (10 - 40,000 Hz) at 1 watt both channels driven simultaneously
Intermodulation DIstortion : Less than 0,15% at full rated output
Input Sensitivity: 1,5 volts for full output
Hum and Noise: better than 85 dB below rated output (Unweighted)
Damping Factor: 30:1 below 20 Hz
Input Impedance: 33,000 Ω
Frequency Response: From below 4 Hz to beyond 70 kHz ±0,5 dB at normal power levels. From below 1 Hz to beyond 100 kHz ±1,0 dB at normal power levels
Square Wave Till: less than 5% at 20 Hz. Typical tilt is less than 2%
Square Wave Rise Time: less than 2 microseconds
Stability: Absolutely stable with all types of speakers including electrostatic
Preamplifier Section
Audio Output: 0 to 2,5 V, RMS, minimum
Frequency Response: from below 3 Hz to above 100 kHz ±0,5 dB
Total Harmonic Distortion : less than 0,05% at 2 V output, 20 - 20,000 Hz
Square Wave Tilt: less than 5% at 20 Hz, Typical 2% at 20 Hz
Square Wave Rise Time: less than 1,5 microseconds
Noise (Unweighted):
Low level: 65 dB below 2 volts at 10 millivolts input reference.
High level: 80 dB below 2 volts, Volume control wide open
Residual : 90 dB below 2 volts
Input Impedance:
Phono : 47 k Ω
Aux : 20 k Ω
Output Impedance: less than 1,000 Ω
Phono Overload: 90 millivolts
Tone Controls: ±12 dB boost and cut, bass and treble
Tuner Section
FM sensitivity: 1,8 mV , IHF
Limiter Saturation: less than 1,5 mV
Ultimate Signal-tonoise: 70 dB
Capture Ratio: less than 2 dB
Alternate Channel Selectivity: better than 50 dB
Image Rejection: 90 dB
Spurious Response Rejection: 90 dB
IF Rejection: 90 dB
Fundamental Plus Half IF: 90 dB
AM rejection: better than 60 dB
Level Meter Sensitivity: 50 mV (25%); 1000 mV (100%)
Audio Frequency Response : Below 15 Hz to beyond 30 kHz ±1,0 dB
Total Harmonic Distortion :
Mono : 0,5%
Stereo : 0,6%
Multiplex Separation:
100 Hz : 33 dB
1 kHz : 38 dB (40 dB typical)
10 kHz : 30 dB
Antenna Impedance: 75 and 300 Ω
AM Loop Sensitivity: better than 200 mV /1m
Selectivity: 35 dB average of lower and upper selectivities
Image Rejection: better than 60 dB
IF Rejection: better than 60 dB
Dimensions (W x H x D): 432 x 349 x 120 mm (17" x 13-3/4" x 4-3/4")
Weight: 13,1 kg (29 lbs)