A Genuine Breakthrough in Inexpensive Integrated Amplifiers (Vol.2, No.2: 1979)

NAD 3020 and NAD 3045

How about a $175 integrated amplifier that wipes out most $1000 preamps plugged into most $1000 power amps, except maybe in sheer wattage? Here's conclusive proof that good, realistic thinking in audio design has nothing to do with dollars.

There's no reason on earth why an integrated amplifier shouldn't be just as good as any preamp/power-amp combi nation. Electrons have no perception of whether the devices they're flowing through are all on one chassis or on two chassis. All compromises associated with integrated amplifiers in the audio purist's mind have to do with the history of hi-fi marketing rather than technical limitations. Historically, cheap and dirty audio amplification has been packaged this way, but that doesn't mean there's anything inherently wrong with the format itself.

As a matter of fact, the integrated format is potentially your best assurance of a correct interface between the pre amplifier and power amplifier sections, assuming that the designer knows what he is doing. Consumers who don't know what they're doing may end up, for example, with a superfast (high slew rate) preamp feeding a much slower power amp that has little or no filtering at its input. The result then is a classic case of TIM. It's also easier to pick up RFI when there's a long cable between the preamp output on one chassis and the power amp input on another, separate chassis.

When it comes to doing a really good job for as little money as possible, the integrated amplifier is of course the only way to go. One power supply instead of two, a lot less metalwork, fewer circuit boards, less wiring-it all adds up to a considerable saving without necessitating any sacrifice in performance as compared to an equivalent two-chassis design. Only the audiophile image suffers, but image is a product of the marketplace, not logic.

Needless to add, all comments on preamplifier and power amplifier testing in this issue are equally applicable to integrated amplifiers. No further introduction is therefore necessary.

NAD 3020 NAD ( USA), Inc., New Acoustic Dimension, Mackintosh Lane, PO Box 529, Lincoln, MA 01773, USA.

Model 3020 Integrated Stereo Amplifier, $175. Two-year warranty. Tested #3225220, on loan from manufacturer.

It looks unassuming rather than cheap-a simple black box with a full complement of controls, including bass and treble, as well as a five-LED peak-power indicator monitoring both channels and displaying the higher output at any instant. The LED's are labeled 1, 5, 10, 20 and 35 watts into 8 ohms; the last is about 22 dB above the obviously ultra conservative 20/20-watt continuous power rating.

The unit came to us very highly recommended, so we threw the toughest test at it right up front. With a variety of speaker systems, we A-B-ed it against our very best preamp/ power-amp combination, the Cotter System 2 feeding the Rappaport AMP-1. (The latter has meanwhile become ex tinct.) The price ratio of A and B in this test was roughly 15 to 1. Well, what can we tell you? Everyone who was listening agreed that the NAD wasn't as good. Everyone also agreed that the difference was amazingly small. Both signal paths sounded clean, transparent, unstrained and musical. The NAD 3020 had a somewhat less open, neutral and finely detailed sound; it clipped a bit sooner; nevertheless, it wasn't really a letdown to switch to it because it was completely free of the hard, ''electronic'' quality of most transistor amplifiers, cheap or expensive. If the Cotter/Rappaport combi nation hadn't been available then and there as a reference, the NAD would have been accepted as just right-that's how good it is. By itself, it's difficult to fault it in clarity, smooth ness and just plain accuracy.

We were able to make further and more detailed listening comparisons, since the 3020 can be separated into its preamp and power amp sections via jacks in the rear. Thus it can be inserted into a reference system either as a preamp or as a power amp and A-B-ed against others. What we found out about it that way is equally impressive. The preamp section ranks just below the top five or six separate pre amplifiers we've tested so far (at any price!) and doesn't sound dramatically inferior to any of them. It never gets hard or over-bright and is just a tad short of the ultimate in transparency. If the RIAA equalization were more accurate, we could almost begin to talk about ''Reference B'' quality. As it is, the error curve drops to -1 dB at 20 Hz, bumps up to +0.2 dB at 430 Hz, and shows a gradual decline above 1 kHz, down to -0.7 dB at 20 kHz in one channel, -0.4 dB in the other. Not too bad, but not excellent. The power amplifier by itself is perhaps even more remarkable; next to the Hafler DH-200, for example, it sounds a little compressed and less open but also smoother and sweeter, without any trace of that hard glint on top. In other words, it isn't totally surpassed by the Hafler, which in turn is surpassed by only six or seven other power amps known to us, at any price. For a $175 amplifier with a free preamp thrown in, that's not bad at all.

The subjectively perceived dynamic headroom of the 3020 can be increased by switching in the 'soft clipping' feature, of which NAD appears to be inordinately proud. In our opinion, this is a double-edged gimmick that takes some of the unpleasantness out of frequent clipping when the amplifier is being pushed but also impairs the depth and three-dimensional detail of the reproduced sound. Our high rating of the NAD 3020 is based on its sonic quality with the soft clipping switch in the off position.

The most interesting question, of course, is how NAD is able to do so much for so little. What do they know that others don't? New Acoustic Dimension is an international organization, originally founded and financed by a group of dealers, with offices in several countries and production facilities in Taiwan. Being dealer-based gives them a realistic outlook on consumer needs; having access to reasonably skilled labor at relatively low cost gives them an edge in price. The 3020 isn't built like a Mark Levinson amplifier but it uses parts of fairly decent quality in all the important places and makes a few compromises wherever the penalty is tolerable. The designer of the entire line is Bjorn-Erik Edvardsen, a Norwegian now living in London, who has some very strong convictions about spending the available production budget on sound rather than cosmetics and sales features. He also seems to have a set of highly intelligent and effectual priorities in circuit design, giving us further evidence in support of our long-standing conviction that good thinking costs no more than bad thinking.

We were fascinated to find, for example, that the 3020 is not only bandwidth-limited to reject infrasonic and ultrasonic garbage but also happens to use high-pass and low-pass characteristics that are very similar to those of the state-of the-art Cotter NFB-2 filter/buffer. Not that the Cotter filter's highly sophisticated time-domain correction is entirely duplicated, but the magnitude of the low-frequency roll-off is about the same, and the measured rise time of 9 micro seconds is exactly the same. What a coincidence and what a corroboration! DC-to-light freaks, eat your hearts out. Correctly bandwidth-limited systems simply sound better. Large output transistors that are just coasting most of the time, not much feedback, a very carefully designed power supply, and no current-limiting protective circuitry are some of the other plausible reasons of the 3020's sonic success. Without any allowance for its low price, this must be considered a thoroughly modern amplifier, designed with total awareness of the errors of the past and obviously capable of handling complex speaker loads with aplomb. We're impressed beyond our wildest expectations.

The one thing that remains to be seen is whether or not the NAD 3020 will perform as impressively after years of heavy use as it does when it's new. We gave our sample as much of a beating as we could and found no change taking place, but we can't make any unqualified promises. It just isn't a mil-spec amplifier. It would be a pity, though, if all the $1000 preamps and $1000 power amps that are better built but don't sound nearly as good outlived it to pollute the ears of our children.

NAD 3045 NAD ( USA), Inc., New Acoustic Dimension, Mackintosh Lane, PO Box 529, Lincoln, MA 01773. Model 3045 Integrated Stereo Amplifier, $350. Two-year warranty. Tested #3459341, on loan from manufacturer.

This one is rated at 45/45 watts into 8 ohms, costs twice as much as the 3020 above, and has a number of extra features, including VU-style power meters on the front panel. It represents, however, an earlier phase of NAD's circuit design philosophy and, in our opinion, doesn't quite achieve the same sonic transparency and smoothness. Next to the 3020, it sounds a tiny bit harder, brighter and less clean-but just. Furthermore, unlike the 3020, it can't be separated into independent preamp and power amp sections.

It does have 32 dB more power, though, when you need it and is otherwise very much in the same mold as the 3020.

We understand that the 3045 is due for early replacement by a new NAD amplifier of comparable power rating that will incorporate everything that's special in the 3020 and then some. Until then this remains a truly excellent product whose only fault is that the 3020 sounds even better and costs less. Had the 3045 been the only NAD amplifier sent to us for testing, our review of it would have been almost as enthusiastic as the one above, with only very minor reservations. Too bad, but it's the old story-the best is the enemy of the good.

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[adapted from TAC]

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Also see:

The New Generation of Power Amplifiers: Amber Series 70; Audionics BA-150; Audire 'Crescendo'; Audire DM700 39 Bedini Model 25/25 ; Bedini Model 45/45; Hafler DH-200 (follow-up); JVC M-7050; PS Model One; Rappaport AMP-1 (epitaph); Sonotron PA-2000

Why We're So Mean, Vindictive, Arrogant, Negative--and Truthful

Various audio and high-fidelity magazines