What is stereo?

There are now two system of high fidelity, monophonic (monaural) and stereophonic. Monophonic is a system that starts from one microphone and is fed through a single high fidelity set. Stereophonic is a double system. Two separate microphones are placed at different sides of the orchestra and two different systems are used to keep the two signals or channels separated. Two separate speakers are used, placed on different sides of you room. Stereo is much like 3-D photography, two slightly different sound reach your ears giving you a new dimension in sound.

H.H. Scott '59

NAD 7020i

7020i Stereo Receiver Features:
 Conservatively rated at 20 W/channel continuous power, with +3 dB of IHF Dynamic Headroom.
Dynamic power exceeds 40 W/channel at 8 or 4 ohms, 50 W/ channel at 2 ohms.
 High-current output stage delivers peak currents up to 15 amperes, for precise control of voice-coilmotion with speaker impedances as low as 2 ohms.
 Gold-plated phono input jacks for a long life of corrosion-free contact in this sensitive low level signal path.
 Heavy duty speaker binding-post connections provide a secure, low resistance connection for allspeaker wires and banana plugs.
 Flexibility: the 7020i's pre and power amplifier are connected by external jumpers which are removable to allow for greater flexibility to upgrade your system.
 Sensitive precise digital tuning with three stages of I.F. filtering for outstanding freedom from noise and interference

The modest cost and simple controls of the NAD 7020i Stereo Receiver make it an ideal choice for theperson who wants fine musical reproduction without becoming involved in the technicalities of hi-fi. NAD's approach to audio design can be characterised in one phrase: "high-value engineering".  When you choose an NAD receiver, you are investing in quality behind the front panel . innovative circuit design, selected parts, high-current transistors, exacting quality control, and solid construction for consistent performance and long-term reliability. The rated "continuous" power of a receiver tells you how well it plays sine-wave test tones; but real musical waveforms are much more complex and dynamic.  The NAD 7020i is conservatively rated at 20 watts per channel for test tones, but its high-voltage design produces extra power for rapidly changing waveforms - over 40 watts per channel of dynamic power for the exciting peaks and climaxes in music (especially in digital Compact Discs). Many FM receivers look good on paper; but in side-by-side comparisons, NAD receivers often pull  inweak or difficult stations with audibly better freedom from noise and interference, thanks to sensitive dual-gate MOSFET amplification and sophisticated multi-stage I.F. filtering

Circuit Features High-Current Output Stage
NAD was the first manufacturer to emphasise the importance of output current capacity. The 7020i candeliver peak currents as high as 15 amperes. The "20-watt" 7020i employs the same high-speed output transistors that other manufacturers use in their "50-watt" receivers.
Impedance Selector
NAD's unique Speaker Impedance selector and high-current output stage deliver maximum power to loudspeakers of any impedance - high or low, simple or complex. The 7020i will even drive a 2 Ω impedance safely, without current-limiting or distortion.
Soft Clipping™
When the 7020i is overdriven beyond its power capacity, the exclusive NAD Soft Clipping™ circuit gently limits the waveform voltage so that the output transistors are never driven into saturation, i.e. into"hard clipping". Thus the receiver can safely be over driven substantially beyond its rated power on peaks, yet still continue to sound smooth and musical.
Digital-ready Dynamic Range
The 7020i's over-load- proof inputs for video, tape and digital Compact Disc  can accommodate a dynamic range greater than 100 dB. Every circuit in the receiver, including its low-impedance tone-control stage, is designed to minimise background noise  and preserve the clarity of your recordings.

Phono Preamplifier
Unlike many receivers that employ low-cost integrated-circuit (IC) chips for the phono stage, the NAD 7020i employs a refined discrete-transistor phono preamplifier circuit whose signal-to-noise ratio is sogood (75 dB with the phono cartridge connected) that you won't hear any preamp hiss, even when playing the quietest recordings.
Musically Useful Tone Controls
Correctly designed tone controls can be a genuinely helpful aid to enjoyable music listening. In the NAD 7020i, the bass and treble controls do what their names imply: they allow you to vary the strength ofthe bass and the treble. But at moderate boost/cut settings the important midrange from 300 to 1500 Hz remains essentially flat.
Sensitive Digital Tuning
The 7020i employs precise frequency-synthesis digital tuning; each station is tuned with crystal-controlled accuracy. A dual-gate MOSFET FM circuit pulls in weak stations well but resists overloading on strong signals, Multi-stage I.F. filtering provides an optimum combination of sharp selectivity (to separate closely-spaced stations) and minimum distortion of the stereo signal.
Quiet AM tuning
The AM section is based on an IC that was especially developed for use in digital tuners, It is surprisingly sensitive, unusually resistant to noise, and provides a more extended high-frequency range than in mostother AM tuning circuits.
Phono Input
Input Impedance (R and C):  40 k Ω (100 pF)
Input Sensitivity (1 kHz):  2,4 mV ref. 20 W
Signal-to-Noise Ratio (A-weighted with cartridge connected):  75 dB ref.5 mV
Total Harmonic Distortion  (20 Hz - 20 kHz):  less than 0,04%
RIAA Response Accuracy (20 Hz - 20 kHz):  ±0,5 db
Line Level Inputs
Input Impedance (R and C):  40 k Ω (100pF)
Input Sensitivity (ref. 20W):  150 mV
Maximum Input Signal:  better than 10 V
Signal-to-Noise Ratio (A-weighted ref 1W):  84 dB
Frequency Response :  20 Hz - 20 kHz,  +0,5 dB; -1,0 dB
Infrasonic Filter:  -3 dB at 15 Hz, 24 dB/oct
Line Level Outputs
Maximum Output Level/Output Impedance:
Tape :  10 V / source Z ÷ 1 k Ω
Phones Max. Output Level : 
Better than 10 V into 600 Ω
Better than 500 mV into 8 Ω
Phones Output Impedance:  220 Ω    
Tone Controls
Treble :  ±7 dB at 10 kHz
Bass :  ±10 dB at 50 Hz
Continuous Output Power into 8 Ω:  20 W (13 dB W)
Rated Distortion (THD 20Hz - 20kHz):  0,03%
Clipping Power (maximum continuous power per channel):  25 W
IHF Dynamic Headroom at 8 Ω :  +2,5 dB
IHF Dynamic Power (maximum short term power per channel):
At 8 Ω :  35 W (15,5 dB W)
At 4 Ω :  35 W (15,5 dB W)
At 2 Ω :  50 W (17 dB W)
Damping Factor(ref. 8 , 50 Hz):  better than 30
Input Sensitivity (for rated power into 8  Ω):  900 mV
Input Sensitivity:
Mono -30 dB T.H.D.÷N :  11,3 dBf (2,0 µV/300 Ω)
Mono 30 dB S/N :  15 dBf 93,0 µV/300 Ω)
Stereo 50 dB S/N :  37 dBf (40 µV/300 Ω)
Stereo 60 dB S/N :  47 dBf (120 µV/300 Ω)
Capture Ratio (45 - 65 dBf):  better than 1,5 dB
AM Rejection (45 - 65 dBf):  better than 60 dB
Selectivity (Alternate Channel):  58 dB
Image Rejection:  70 dB  
I F Rejection:  90 dB
Harmonic Distortion [mono/stereo]:  0,1% / 0,1%
Signal-to-Noise Ratio [mono/stereo]:  better  than 80 dB/ better than 74 dB
Frequency Response:  30 Hz - 15 kHz,   ±0.5dB
Channel Separation at 1kHz:  45 dB
Usable Sensitivity:  5 µV
Selectivity:  30 dB
Image Rejection:  45 dB
I F Rejection:  35 dB
Signal-to-Noise Ratio:  45 dB
Harmonic Distortion:  0,5%
Power Supply:  120 ~ 240 V, 50/60 Hz
Power Consumption:  150 W
Dimensions (W x H x D):  420 x 91 x 273 mm
Net /Shipping Weight :  5,5 / 6,8 kg

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