NAD - 3020

legendary integrated amplifier

New Acoustic Dimension is the full name of the NAD company founded in 1972 in London, founded by an electrical engineer with a PhD in physics, Martin L. Borish. The company was focused on the production of inexpensive audio devices that were serious competition on the market of Hi-Fi devices. What distinguishes NAD products from budget competitors is the design of the power supply developed by Phill Marshall, which provides a large reserve of power.

The technology uses a large current reserve, which is released at times of heavy music load. The power supply designed in this way is able to provide adequate power and control over low impedance loudspeakers.

The NAD 3020 is a stereo integrated amplifier launched in 1978. It was produced and sold until 1998, gaining the reputation of audiophiles and the title of the best-selling amplifier in the history of audio. NAD 3020 has undergone several modifications that introduced changes:

OVER 3020: (10Hz-70kHz, 20W, THD 0.02%)
NAD 3020B: (10Hz-70kHz, 25W, THD 0.02%)
OVER 3020E: (20Hz-20kHz, 25W, THD 0.05%)
NAD 3020 and: (6Hz-80kHz, 20W, THD 0.03%)

The NAD 3020 delivers 20 watts per channel into an 8 ohm load. The front of the amplifier is made of a characteristic gray plastic. On the front panel, next to the power switch, there is a 6.35mm headphone jack and 3 potentiometers for Bass / Trable and Balance. Next to them are square Aux/Tuner/Phono/Tape selection buttons along with Audio Muting and Loudness boost buttons. Above the volume potentiometer on the right side there are 5 red diodes indicating the momentary load level of the amplifier (1 / 5 / 10 / 20 / 35W) at 8 Ohm calibration. Thus, if the load is 4 Ohm, the actual power is twice as much as indicated. On the back, on the horizontally arranged connectors, there are self-locking speaker terminals that accept only bare wires with a maximum thickness of approx. 3mm. The amplifier has a screw ground terminal for the adjacent RCA inputs intended for a turntable with an MC cartridge with an output level of at least 2.5 mV. The installed RCA connectors are not marked with colored plugs (red for the right and black for the left channel) as is the case with most amplifiers and peripherals. On the wall located behind the connectors there is a list of input / output markings along with a drawing illustrating the marking of the right and left channels. The amplifier has a TAPE (Play / Rec) input and output in the RCA plug standard as well as the 5-pin DIN connector used at that time. Metal jumpers separated the preamplifier (Pre-Amp Out), which after switching the jumpers can work in NORMAL-IN mode without affecting the frequency range from 20 Hz - 20 kHz. Changing the jumpers to the LAB-IN output enables the SOFT-CLIPPING (On/Off) filter to clip high-level abrupt distortions. Thanks to this treatment, the sounds of high and medium frequencies are effectively cleaned, allowing you to play louder without subjective distortion.

The old technology of budget amplifiers, which includes the reviewed NAD 3020, had several design flaws that may not use the full potential of this amplifier. It should be mentioned here about the poor quality of RCA inputs placed horizontally, which makes it much more difficult (or even impossible) to connect rigid interconnects. The lack of color marking forces the amplifier to be reversed anyway in order to correctly connect the inputs / outputs described on the rear panel. The biggest noticeable disadvantage are the budget terminals, which make it impossible to connect good quality speaker cables with popular banana plugs or spades. As if that was not enough, the manufacturer limited us to the use of speaker wires with a thickness not exceeding 3mm.

NAD 3020, thanks to its large current reserve, is able to provide a strong dynamic musical message for even demanding speakers. The sound of this award-winning amplifier is spacious, tight and rich in detail. For the test of the NAD 3020, 8 Ohm bookshelf loudspeakers Bowers & Wilkins - DM 600 S3 were used. Since the NAD amp uses spring clips that only accept bare speaker wires, I was forced to use unearned REGA FSC Quattro speaker wires that have not been used since time immemorial. The amplifier worked with the source supplied from the Marantz CD7300 CD player (read the Marantz review) and the Technics SL100C turntable with the AT-VM95C cartridge from Audio-Technika (read the Technics review). The interconnects used for the test were The Chord Cadenza, QED - Qunex Silver Spiral and Audioquest - Tower.

NAD 3020 sound compared to:

CD player: Marantz CD 7300
speakers: Bowers & Wilkins - DM600 S3
speaker cables: REGA FSC Quattro
interconnect: Chord-Cadenza / QED-Silver Spiral

The sound in normal mode from the SACD disc was lifeless, it suffered from the lack of dynamics of the small Bowers. After turning on the Loudness mode, the sound gained a large space with good differentiation of the right and left stereo channels. Bass was still limited on the bottom end and didn't provide adequate mid-bass fill. This was most likely due to the small volume of the B&W-DM 600 S3 loudspeaker housing. What drew attention was the rich background and virtual sources. The female and male chorus resounded with a lot of air. The wind instruments lacked clarity, but the treble was very legible and clear. Changing the interconnect to QED - Qunex Silver Spiral with Loudness turned on in NAD brought a big improvement, the sound gained additional scale and a wider stereo image. The instruments were presented cleaner, and the vocals gained a stronger and more colorful message. The keys lacked the upper coloring, which made them seem slightly dull. Switching the NAD to the filtered SOFT-CLIPING mode and turning off the Loudness boost brought more order to the stage, the sounds became clearer with better controlled bass, which sounded very correct and was well differentiated in timbre. Vocals gained more color and transparency, making them more readable and tangible. It was the best and most correct sounding configuration in the test. It provided an interesting and rich insight into the musical material supported by a depleted but very good quality bass providing many nuances. The sound had a studio pedigree of well-differentiated, colorful and well-lit sounds that really lacked nothing.

NAD 3020 bundled with:

turntable: Technics SL-100C (with AT-VM95C)

speakers: Bowers & Wilkins – DM 600 S3

speaker cables: REGA – FSC Quattro

interconnect: Audioquest - Tower

subwoofer: REL-T5i

The sound was calm, not tiring and tonally correct (it did not bring warmth or brightness). The lack of a sense of the presence of filling the lower band by the connected REL T5i subwoofer strongly surprised and gave a feeling of unsatisfactoriness in low frequencies. The treble presented the reverberations of the cymbals in a clear and differentiated way, which did not fall into the metallic character known from the metal Bowers domes. Electric guitars legibly and colorfully reflected the correct level of generally correct sound in every aspect presented on the stage. The vocals sounded clear and correct with a good presence of backing vocals keeping the right distance.

Conclusion

The old NAD 3020 integrated amplifier from 1978 is to this day an example of a cheap, good-sounding device that is able to deliver tonally correct and detailed hi-fi stereo sound.

Technical data

power: 20 watts per channel into 8 Ohms

frequency response: 10Hz - 70kHz

attenuation factor: 55

input sensitivity: 2.5 mV (for MC input), 150 mV for other RCA inputs

filters: SOFT-CLIPPING (On/Off) / Loudness (On/Off)

phono preamplifier: Magnetic Cartridges (MC)

Pre-Amp Out: (normal operation with the option of switching to filtered mode)

possibilities: the ability to work as a stereo preamplifier

speaker terminals: spring clips accepting wires up to 3mm in diameter

dimensions: 420mm / 96mm / 240mm

scales: 5.25 kg

Elaborated by: Łabędź Przemysław