7
ON TEST 50 www.avhub.com.au Australian Hi-Fi A few years ago Naim embarked on a project to produce a preampli- fier and power amplifier combo that it intended to be a testament to the company’s design and engineering capabilities. The budget was un- limited, and all involved were told by Naim’s management team: ‘no holds barred, let it rip…’ The result was the Naim ‘Statement’ amplifier system which, at near $360,000 in Australian money, still stands as the pinnacle of Naim Audio’s technological expression in amplification. But for Naim’s engineers, having mani- fested their greatest artistic creation, what remained? Basically, their next challenge was to trickle-down aspects of the new technol- ogy into more affordable ‘bread-and-butter’ products that would be more financially accessible not only to Naim’s ardently loyal client base, but also to new customers. Hence it is that the new Naim NAP 250DR uses exactly the same Naim-designed custom output transistors as the Statement, as well as the self-same discrete regulators (DRs) as the flagship amplifier…just not quite so many of them! The impetus for the development of Naim’s own transistors was the company’s belief that all standard-issue transistors possess limitations in terms of power and thermal saturation that were not befitting of an all-out ‘Statement’ design. So, in conjunction with a specialist semiconductor manufacturer, Naim created its own bipolar transistors (NA009N/ NA009P), the design of which it says enables better thermal connection to the heat sink, which in turn reduces temperature fluctuations in the transistor’s silicon, and according to Naim, it’s these temperature fluctuations that cause a transistor’s characteristics to dynamically change, which is obviously an undesirable trait. The new NA009 transistors contain no ferrous materials at all: they even have pure copper legs. In addition, the Discrete Regulator (DR) technology used in the flagship product now features in the NAP 250DR—as reflected by its nomenclature. As you’d guess from the word ‘discrete’, voltage regulation is achieved via the use of discrete components and the d.c. voltage reference is supplied by a 7-volt ‘buried’ zener diode, rather than a standard zener device. Newport Test Labs Power Output Test Result Graph: Single channel driven into 8-ohm, 4-ohm and 2-ohm non-inductive loads at 20Hz, 1kHz and 20kHz. [Naim NAP 250DR Integrated Amplifier] NAIM NAP 250DR POWER AMPLIFIER

on test · on test Naim nAP 250DR PoweR AmPlifieR 52 Australian Hi-Fi So there’s an impression of attack and speed in the way that drums, for example, fire …

  • Upload
    others

  • View
    0

  • Download
    0

Embed Size (px)

Citation preview

Page 1: on test · on test Naim nAP 250DR PoweR AmPlifieR 52 Australian Hi-Fi  So there’s an impression of attack and speed in the way that drums, for example, fire …

on test

50 www.avhub.com.auAustralian Hi-Fi

A few years ago Naim embarked on a project to produce a preampli-fier and power amplifier combo that it intended to be a testament to the company’s design and

engineering capabilities. The budget was un-limited, and all involved were told by Naim’s management team: ‘no holds barred, let it rip…’ The result was the Naim ‘Statement’ amplifier system which, at near $360,000 in Australian money, still stands as the pinnacle of Naim Audio’s technological expression in amplification.

But for Naim’s engineers, having mani-fested their greatest artistic creation, what remained? Basically, their next challenge was to trickle-down aspects of the new technol-ogy into more affordable ‘bread-and-butter’ products that would be more financially accessible not only to Naim’s ardently loyal client base, but also to new customers. Hence it is that the new Naim NAP 250DR uses exactly the same Naim-designed custom

output transistors as the Statement, as well as the self-same discrete regulators (DRs) as the flagship amplifier…just not quite so many of them!

The impetus for the development of Naim’s own transistors was the company’s belief that all standard-issue transistors possess limitations in terms of power and thermal saturation that were not befitting of an all-out ‘Statement’ design. So, in conjunction with a specialist semiconductor manufacturer, Naim created its own bipolar transistors (NA009N/ NA009P), the design of which it says enables better thermal connection to the heat sink, which in turn reduces temperature fluctuations in the transistor’s silicon, and according to Naim, it’s these temperature fluctuations that cause a transistor’s characteristics to dynamically change, which is obviously an undesirable trait. The new NA009 transistors contain no ferrous materials at all: they even have pure copper legs.

In addition, the Discrete Regulator (DR) technology used in the flagship product

now features in the NAP 250DR—as reflected by its nomenclature. As you’d guess from the word ‘discrete’, voltage regulation is achieved via the use of discrete components and the d.c. voltage reference is supplied by a 7-volt ‘buried’ zener diode, rather than a standard zener device.

Power Output: Single channel driven into 8-ohm, 4-ohm and 2-ohm non-inductive loads at 20Hz, 1kHz and 20kHz. [NAP250]

New

po

rt T

est

Lab

s

Power Output Test Result Graph: Single channel driven into 8-ohm, 4-ohm and 2-ohm non-inductive loads at 20Hz, 1kHz and 20kHz. [Naim NAP 250DR Integrated Amplifier]

Naim NaP 250DR PoweR amPlifieR

Page 2: on test · on test Naim nAP 250DR PoweR AmPlifieR 52 Australian Hi-Fi  So there’s an impression of attack and speed in the way that drums, for example, fire …

on testNaim nAP 250DR PoweR AmPlifieR

51Australian Hi-Fi

The equipmenTLittle needs to be said about the front panel of the Naim NAP 250DR, because it’s com-pletely bare save for a single mains power switch at the extreme right and the little green Naim ‘bridge’ logo that glows when the amplifier is switched on. But if you look around the back of the NAP 250DR you’ll see that—and I must say ‘typically for Naim’—connectivity is…well… different.

Firstly, only banana connectors need apply at the amp’s speaker outputs with the almost-flush sockets accepting neither spades nor bare wire. Then, there’s that lone XLR input (which almost tricked me into thinking I’d erroneously received a mono amp) that’s not actually a standard XLR socket, because pins 2 and 3 are wired ‘hot left’ and ‘hot right’ in order to facilitate stereo operation (with pin 1 as the common ground). Naim provides a connecting cable wired for this unique XLR arrangement at the amp’s end that is DIN-terminated at the preamplifier end. So using anything other than a Naim de-vice to ‘drive’ the NAP 250DR is not possible unless you obtain an appropriately-terminat-ed cable to connect your preferred pream-plifier’s twin output (whether RCAs or XLRs) to the single XLR input on the NAP 250DR. Irrespective of the benefits claimed for this arrangement, I find that in principle it’s… insular… and limiting. Apple anyone?

So, in order to facilitate this review the local Aust/NZ Naim distributor, NA Distribu-tors, provided me with Naim’s Bluetooth- and App-empowered NAC-N 272 preamplifier/streamer/DAC and it was this that I used

(in conjunction with the requisite DIN-XLR cable connecting it to the NAP 250DR, with all my source components in my system remaining as per reference. The NAC-N272 retails for $6,950.

The company also supplied me with an older NAP 250 power amplifier, so I could compare ‘old’ with ‘new’… so to speak. As you have no doubt guessed, the older NAP 250 continues on in the company’s product line-up, currently with a recommended retail price of $6,700.

According to Steve Sells, of Naim, there are no differences in the basic amplifier circuitry between the NAP 250 and the NAP 250DR…except that DR version has had a few component values changed to accom-modate the NA009 output transistors. The power supply circuitry, on the other hand, is completely different, with Sells claiming it’s essentially a smaller version of that found in the Statement NAP S1—a highly regulated (using those discrete regulators) high-current power supply that Naim claims is ‘30 times quieter’ than the NAP 250’s power supply, and ‘maintains a more constant voltage under heavy speaker driving conditions’.

Specs-wise, Naim specifies the NAP 250DR as having a power output of 80 watts into 8Ω loads and its frequency response as 3Hz to 50kHz –3dB. On the purely physical side,

the NAP 250DR measures 87×432×314mm (HWD) and weighs 15.8kg.

DifferenT TwinsMy auditions started with the older NAP

250 amplifier in order that I could ascertain the original’s sonic signature. And yes, let me state this straight off the bat, the clichéd PRaT descriptor does apply here. The NAP 250 jumps at rhythms in a most propulsive way across the frequency range—not just in the bass response.

Power Output: Both channels driven into 8-ohm, 4-ohm and 2-ohm non-inductive loads at 20Hz, 1kHz and 20kHz. [NAP-250]

New

po

rt T

est

Lab

s

Power Output: Single and both channels driven into 8-ohm, 4-ohm and 2-ohm non-inductive loads at 20Hz, 1kHz and 20kHz. [NAP-250]

Power Output Test Result Graph: Single channel driven into 8-ohm, 4-ohm and 2-ohm non-inductive loads at 20Hz, 1kHz and 20kHz. [Naim Audio NAP-250DR Integrated Amplifier]

Power Output Test Result Graph: Single channel driven into 8-ohm, 4-ohm and 2-ohm non-inductive loads at 20Hz, 1kHz and 20kHz. [Naim NAP-250DR Integrated Amplifier]

Naim uses its own bipolar transistors (NA009N/ NA009P) in the new NAP-250DR, the design of which it says enables better thermal connection to the heat sink, which in turn reduces temperature fluctuations in the transistor’s silicon, and according to Naim, it’s these temperature fluctuations that cause a transistor’s characteristics to dynamically change, which is obviously an undesirable trait.

Page 3: on test · on test Naim nAP 250DR PoweR AmPlifieR 52 Australian Hi-Fi  So there’s an impression of attack and speed in the way that drums, for example, fire …

on test Naim nAP 250DR PoweR AmPlifieR

www.avhub.com.au52 www.avhub.com.auAustralian Hi-Fi

So there’s an impression of attack and speed in the way that drums, for example, fire towards the listening seat. The snare and kick drum crisply and tightly pulse energy and establish an engaging fast rhythmic pace.

Also on offer were superb low level and overall detail retrieval, good separation of dense mix layers and an overall smooth to-nality. Bass power was good—if not hat-blow-ing—while the NAP 250 presented excellent image accuracy laterally within a very wide—if somewhat shallow-ish—soundstage.

On an operational level, my sample NAP 250 displayed a noticeable turn-on ‘thump’ via my reference Wilson Audio speakers which, being very sensitive, tend to exag-gerate such foibles. Your speakers’ sensitivity will determine the volume of the thump. Enter the NAP 250DR. No more thump. First thumbs-up. Subsequent—and I’ll add numerous—thumbs-ups came via both subtle and not-so-subtle sonic improvements over the NAP 250. For starters, the NAP 250DR has a noticeably more dynamic presentation with contrasts in musical amplitude being both more pronounced and real-sounding. Several of my dynamics torture tests featuring well-produced drums, powerful orchestral, rock and world music recordings showed the DR in the model name could just as well stand for Dynamic Range compared to the straight NAP 250.

A surprise came via Argentinean prog-tango Sera Una Noche where the NAP 250DR showed a clean set of heels to its predecessor in the way it handled treble decay with instruments such as bells and cymbals in a number of tracks throughout this revelatory recording. The Naim NAP 250DR beautifully conveyed the harmonics and delicate detail of upper high frequencies while maintaining superb timbral signatures throughout the bandwidth.

Brand: Naim

model: NAP 250DR

rrp: $8,000

warranty: Two Years

Distributor: N.A. Distributors

Address: PO Box 9187, Marion Square

Wellington

New Zealand 6141

T: (02) 8005 0670

e: [email protected]

w: www.naimaudio.com.au

ConnectivityVolume controlStandby power

PRaTDynamicsBuild quality

Naim NaP 250DR PoweR amPlifieR

The soundstage of the NAP 250DR is also deeper and seemingly more layered than its predecessor, whereas its width and image placement are simply on par. In my listening room there most definitely was an impression of increased distance between the vocalist and instrumentalists in live recordings, as well as an increased sense of the venue’s ambience.

The transient attack and ‘speed’ I referred to regarding the NAP 250 is maintained on the NAP 250DR. The superbly-captured snare on Like a King and Whipping Boy from Ben Harper’s ‘Welcome to the Cruel World’ snapped with terrific projection while cutting through the solid bass foundation without impinging on the clarity of Harper’s subtle vocals.

Appropriate weight and emotional con-nection was given to Johnny Cash’s aged and deep growl on Hurt from ‘American IV: The Man Comes Around’. And although this track may seem simple enough for any competent amplifier to reproduce effectively, it’s an as-tutely balanced one that can produce clarity in the vocals juxtaposing the crescendo as it builds to accentuate the sentiment behind the lyric’s message. Similar findings applied to Patty Larkin’s Winter Wind from ‘Angels Running’ where Larkins’ voice is present and floats on a platform of warm and full-bodied guitar chords.

The one consistent factor with both am-plifiers but more so, to a considerable extent, in the NAP 250DR, is the connection with the music being replayed. I noticed I became immersed in the performance and relaxed into the listening experience so deeply that I found myself constantly having to make a conscious effort to don my ‘reviewer’s hat’ in order to write down these evaluations. These amplifiers invite listening and involvement.

ConClusionEverything that Naim does it does in a distinctively individual way—and always has—from the minimalist styling that carries across all its products, to the circuitry it designs, and right down to the proprietary connectivity. To my mind, the company is making a clear statement here, which is ‘Follow us on our path and we’ll take you to the music.’ And with the NAP 250DR this is just the destination. Edgar Kramer

Page 4: on test · on test Naim nAP 250DR PoweR AmPlifieR 52 Australian Hi-Fi  So there’s an impression of attack and speed in the way that drums, for example, fire …

53Australian Hi-Fi

lAb RePoRtNaim nAP 250DR PoweR AmPlifieR

Naim NAP 250DR Power Amp – Lab Test Results – Power Output

Channel Load (Ω) 20Hz

(watts)

20Hz

(dBW)

1kHz

(watts)

1kHz

(dBW)

20kHz

(watts)

20kHz

(dBW)

1 8 Ω 90 19.5 90 19.5 85 19.2

2 8 Ω 89 19.4 89 19.4 84 19.2

1 4 Ω 156 21.9 157 21.9 140 21.5

2 4 Ω 155 21.9 156 21.9 137 21.4

1 2 Ω 248 23.9 244 23.8 89 19.4

2 2 Ω 180 22.5 239 23.7 80 19.0

Naim NAP 250DR Power Amplifier – Laboratory Test ResultsTest Measured Result Units/Comment

Frequency Response @ 1 watt o/p 4Hz – 39kHz –1dB

Frequency Response @ 1 watt o/p 2Hz – 70kHz –3dB

Channel Separation (dB) 91dB / 90dB / 68dB (20Hz / 1kHz / 20kHz)

Channel Balance (Direct/Tone) 0.007 dB @ 1kHz

Interchannel Phase (Direct) 0.15 / 2.41 / 5.95 degrees ( 20Hz / 1kHz / 20kHz)

THD+N 0.012% / 0.009% @ 1-watt / @ rated output

Signal-to-Noise (unwghted/wghted) 76dB / 83dB dB referred to 1-watt output

Signal-to-Noise (unwghted/wghted) 94dB / 100dB dB referred to rated output

Input Sensitivity 105mV / 934mV (1-watt / rated output)

Output Impedance 0.2Ω at 1kHz

Damping Factor 40 @1kHz

Power Consumption NA / 15.98 watts (Standby / On)

Power Consumption 58 / 374 watts at 1-watt / at rated output

Mains Voltage Variation during Test 238 – 252 Minimum – Maximum

The Naim NAP 250DR power amplifier only just exceeded its manufacturer’s claim for power output into 8Ω, as you can see both from the tabulated results and from the bar graphs accompanying this review. New-port Test Labs measured output at 1kHz as 89-watts per channel, both channels driven into 8Ω. As you’d expect, given the regulated power supply, power output with only a sin-gle channel driven was almost identical. Into 8Ω loads, power output was maintained at 89-watts at 20Hz, but dropped almost infini-tesimally at 20kHz to 85-watts per channel… still higher than specification.

When driving 4Ω loads, the Naim NAP 250DR came within a whisker of meeting the theoretically ‘perfect’ ideal of doubling its power output… but not quite, with the amplifier delivering 156-watts per channel at 1kHz, 155-watts per channel at 20kHz and 137-watts per channel at 20kHz. Since Naim quotes power output at 150-watts per channel into 4Ω for the NAP 250DR, this puts the result at 20kHz just slightly under specification. The difference is so slight, however, that if the 240 mains voltage had been held stable (it varied between 238 volts and 252 volts during the testing), an output of 150-watts per channel at 20kHz may have been achieved on test.

Naim puts the recommended ‘minimum load impedance’ for the NAP 250DR at 2Ω, but not surprisingly, the amplifier’s output did not redouble when the amplifier was driving 2Ω loads, though it still delivered a

Laboratory test report

high frequencies. Within the audio band, the response was 20Hz to 20kHz ±0.1dB when driving a non-inductive load, and 20Hz to 20kHz ±0.25dB when driving a highly induc-tive (and capacitive) load that simulates that of a two-way bass reflex loudspeaker. Both these traces are shown on Graph 6. Channel separation was excellent at low frequencies (91dB at 20Hz), still excellent at 1kHz (90dB) but dropped down to 68dB at 20kHz. This is still far more separation than will ever be required for perfect stereo imaging and channel separation but it is a little lower than I might have expect from power amplifier. Inter-channel phase was appreciably better, coming in at 0.02° at 20kHz and swinging to just 5.95° at 20kHz. Channel balance was outstandingly good, one of the best figures I have seen, coming in at 0.007dB.

very creditable 239-watts per channel both channels driven at 1kHz and 180-watts both channels driven at 20kHz. When tested into 2Ω loads using a high-frequency (20kHz) test signal however, the amplifier’s protec-tion circuitry cut in to limit power output to 80-watts per channel. In practise this really won’t matter, since music will never contain continuous signals at 20kHz and, if the amplifier was producing its maximum output into 2Ω at low and mid-frequencies, the spectrum of music is such that an output of 80-watts at 20kHz would be more than sufficient to deliver all the high-frequency musical information at the correct playback levels. Frequency response was very good, with the amplifier reaching down to 4Hz (–1dB) and 2Hz (–3dB) in the low frequencies, and out to 39kHz (–1dB) and 70kHz (–3dB) at

When driving 4Ω loads, the Naim NAP 250DR came within a whisker of meeting the theoretically ‘perfect’ ideal

Page 5: on test · on test Naim nAP 250DR PoweR AmPlifieR 52 Australian Hi-Fi  So there’s an impression of attack and speed in the way that drums, for example, fire …

lAb RePoRt

54 www.avhub.com.auAustralian Hi-Fi

Naim nAP 250DR PoweR AmPlifieR

0.00 Hz 4000.00 8000.00 12000.00 16000.00 20000.00-140.00

-120.00

-100.00

-80.00

-60.00

-40.00

-20.00

0.00dBFS

Graph 1: Total harmonic distortion (THD) at 1kHz at an output of 1-watt into an 8-ohm non-inductive load, referenced to 0dB. [Naim NAP 250 Power Amplifier]

Newport Test Labs

0.00 Hz 4000.00 8000.00 12000.00 16000.00 20000.00-140.00

-120.00

-100.00

-80.00

-60.00

-40.00

-20.00

0.00dBFS

Graph 2: Total harmonic distortion (THD) at 1kHz at an output of 1-watt into a 4-ohm non-inductive load, referenced to 0dB. [Naim NAP 250 Power Amplifier]

Newport Test Labs

Graph 1: Total harmonic distortion (THD) at 1kHz at an output of 1-watt into an 8-ohm non-inductive load, referenced to 0dB. [Naim Audio NAP-250DR Integrated Amplifier]

Graph 2: Total harmonic distortion (THD) at 1kHz at an output of 1-watt into a 4-ohm non-inductive load, referenced to 0dB. [Naim Audio NAP-250DR Integrated Amplifier]

0.00 Hz 4000.00 8000.00 12000.00 16000.00 20000.00-140.00

-120.00

-100.00

-80.00

-60.00

-40.00

-20.00

0.00dBFS

Graph 3: Total harmonic distortion (THD) at 1kHz at rated output (80-watts) into an 8-ohm non-inductive load, referenced to 0dB. [Naim NAP 250 Power Amplifier]

Newport Test Labs

Graph 3: Total harmonic distortion (THD) at 1kHz at an output of 150-watts into an 8-ohm non-inductive load, referenced to 0dB. [Naim Audio NAP-250DR Integrated Amplifier]

0.00 Hz 4000.00 8000.00 12000.00 16000.00 20000.00-140.00

-120.00

-100.00

-80.00

-60.00

-40.00

-20.00

0.00dBFS

Graph 4: Total harmonic distortion (THD) at 1kHz at rated output (150-watts) into a 4-ohm non-inductive load, referenced to 0dB. [Naim NAP 250 Power Amplifier]

Newport Test Labs

Graph 4: Total harmonic distortion (THD) at 1kHz at an output of 300-watts into a 4-ohm non-inductive load, referenced to 0dB. [Naim Audio NAP-250DR Integrated Amplifier]

Distortion at a power output of 1-watt was very low, as you can see from Graph 1 (8Ω load) and Graph 2 (4Ω load). At one watt into 8Ω, the NAP 250DR’s output spectrum contained a second harmonic distortion com-ponent at –98dB (0.0012%), a third at –95dB (0.0017%), a fifth at –107dB (0.0004%) and a seventh at –113dB (0.0002%). The peaks to the left of the graph are low-frequency noise components at 50Hz, 100Hz and 150Hz. The level of the second and third harmonic

distortion components increased when the amplifier was driving 4Ω loads, but only to –90dB (0.0031%).

Driving 4Ω loads at 1kHz a fourth har-monic became obvious (at least visually!) at –114dB (0.0001%) while the fifth and seventh harmonics remained at approximate-ly the same levels as when the amplifier was driving 8Ω loads. The levels of low-frequency components also rose a little, the result of the power supply having to work harder when the amplifier is driving 4Ω loads. The very low levels of distortion, combined with the

complete absence of higher-frequency dis-tortion components suggests to me that the amplifier would have a completely neutral tonal character in this regard.

Distortion levels increased when the NAP 250DR was operating at its maximum output power. At 80-watts into 8Ω, a 1kHz test signal resulted in a second harmonic distortion component at –85dB (0.0056%), a third at –90dB (0.0031%), a fourth at –95dB (0.0017%), a fifth at –96dB (0.0015%), a sev-enth at –104dB (0.0006%) and an eighth at 106dB (0.0005%). As you can see from Graph 3, higher-order components are also present, but they’re all around –120dB (0.0001%) or lower. These levels of distortion would be completely inaudible.

The same observation can be made for the NAP 250DR’s distortion into 4Ω loads at an output of 150-watts per channel. You can see that the amplifier is having a little more difficulty with the lower impedance, so that

distortion is slightly higher, but apart from the second harmonic at –82dB (0.0079%) and the fifth at –86dB (0.005%), the first nine harmon-ics are all more than 90dB down (0.0031%) and most are down at –100dB (0.001%).

IMD was low, particularly the higher-order sidebands, which averaged around –90dB (0.0031%) for the first pair (18 and 21kHz), around –100dB (0.001%) for the second pair (17 and 22kHz) and –105dB (0.0005%) for the third pair of sidebands at 16 and 23kHz. The unwanted 1kHz regeneration was at –98dB (0.0012%). Ignore the noise at the left of this graph: it’s the result of a transient measure-ment error.

Newport Test Labs measured the signal-to-noise ratio of the NAP 250DR at 76dB un-weighted and at 83dB A-weighted, referred to a one watt output. Referenced to rated output, these results improved to 94dB unweighted and 100dB A-weighted. These figures came on the back of a fairly high input sensitivity,

Newport Test Labs measured the signal-to-noise ratio of the NAP 250DR at 100dB A-weighted

Page 6: on test · on test Naim nAP 250DR PoweR AmPlifieR 52 Australian Hi-Fi  So there’s an impression of attack and speed in the way that drums, for example, fire …

lAb RePoRt

55Australian Hi-Fi

Naim nAP 250DR PoweR AmPlifieR

0.00 Hz 6000.00 12000.00 18000.00 24000.00 30000.00-140.00

-120.00

-100.00

-80.00

-60.00

-40.00

-20.00

0.00dBFS

Graph 5: Intermodulation distortion (CCIF-IMD) using test signals at 19kHz and 20kHz, at an output of 1-watt into an 8-ohm non-inductive load, referenced to 0dB. [Naim NAP 250 Power Amplifier]

Newport Test Labs

Graph 5: Intermodulation distortion (CCIF-IMD) using test signals at 19kHz and 20kHz, at an output of 1-watt into an 8-ohm non-inductive load, referenced to 0dB. [Naim Audio NAP-250DR Integrated Amplifier]

10.00 Hz 100.00 1000.00 10000.00-3.00

-2.50

-2.00

-1.50

-1.00

-0.50

0.00

0.50

1.00

1.50

2.00

2.50

3.00dBr

Graph 6: Frequency response of line input at an output of 1-watt into an 8-ohm non-inductive load (black trace) and into a combination resistive/inductive/capacitive load representative of a typical two-way loudspeaker system (red trace). [Naim NAP 250 Power Amplifier]

Newport Test Labs

Graph 6: Frequency response of line input at an out-put of 1-watt into an 8-ohm non-inductive load (black trace) and into a combination resistive/inductive/capacitive load representative of a typical two-way loudspeaker system (red trace). [Naim Audio NAP-250DR Integrated Amplifier]

with the Naim requiring only 105mV at its input for a 1-watt output, and only 934mV for rated power output.

Square wave performance was exemplary, with the 100Hz square wave showing barely any tilt (as would be expected from the nearly d.c. low-frequency extension). The 1kHz square wave, although not perfect, showed only modest rounding on the leading edge, with the rounding on the 10kHz wave being more evident but typical. Undoubted star of the show, however, was the square wave reproduction when the Naim was driving a highly capacitive load, which was completely atypical. There is a tiny amount of ringing, but it’s so negligible that it’s barely visible at all, so not only will this amplifier be stable into all loudspeaker loads, it should also ‘sound’ good in listening sessions, as amplifiers exhibiting this type of performance have in the past typically been rated very highly in subjective listening tests with all types of loudspeakers.

Damping factor was relatively low (40 at 1kHz) but even at this level is sufficient to handle the back-emf from large bass drivers. Mains power consumption at idle was 15.98-watts, increasing to 58-watts at a continuous output of 1-watt and topping out

at 374-watts when the amplifier is operating at full power into 8Ω loads.

My opinion is that the Naim NAP 250DR performed very well on Newport Test Labs’ test bench. Steve Holding

Page 7: on test · on test Naim nAP 250DR PoweR AmPlifieR 52 Australian Hi-Fi  So there’s an impression of attack and speed in the way that drums, for example, fire …

figure 2. Total harmonic distortion (THD) at 1kHz at an output of 1-watt into a 4-ohm non-inductive load, referenced to 0dB. [Lavardin IT Integrated Amplifier]

figure 3. Total harmonic distortion (THD) at 1kHz at an output of 52-watts into an 8-ohm non-inductive load, referenced to 0dB. [Lavardin IT Integrated Amplifier]

figure 1. Total harmonic distortion (THD) at 1kHz at an output of 1-watt into an 8-ohm non-inductive load, referenced to 0dB. [Lavardin IT Integrated Amplifier]

figure 4. Total harmonic distortion (THD) at 1kHz at an output of 57-watts into a 4-ohm non-inductive load, referenced to 0dB. [Lavardin IT Integrated Amplifier]

figure 5. Intermodulation distortion (CCIF-IMD) using test signals at 19kHz and 20kHz, at an output of 1-watt into an 8-ohm non-inductive load, referenced to 0dB. [Lavardin IT Integrated Amplifier]

figure 6. Frequency response of line input at an output of 1-watt into an 8-ohm non-inductive load (black trace) and into a combination resistive/inductive/capacitive load representative of a typical two-way loudspeaker system (red trace). [Lavardin IT Integrated Amplifier]

lab report

85Australian Hi-Fi

New Subscription or Extend Subscription or Gift Subscription

Mr Mrs Miss Ms

Your Name

Your Address

Postcode

Daytime Phone ( )

E-mail

IF A GIFT SUBSCRIPTION Mr Mrs Miss Ms

Recipient’s Name

Recipient’s Address

Postcode

Daytime Phone ( )

E-mail

Terms and conditions: Price offer available to Australian and NZ residents only and expires 18/12/16. All prices include GST. Savings based on total cover price. Overseas Airmail 14 issues A$195 or 7 issues A$99. Australian Hi-Fi subscription comprises of 7 issues PA – 6 regular issues and 1 special issue. Subscriptions commence with the next available issue. Please allow 6-8 weeks for delivery of your first magazine. This form may be used as a Tax Invoice. nextmedia Pty Limited ABN 84 128 805 970. Please tick if you do not wish to receive special offers or information from nextmedia or its partners via mail email. For full Privacy Notice, refer to www.nextmedia.com.au. If you would prefer to receive your communication electronically, please ensure we have your current email address. M

A/H

F611

PAYMENT DETAILS

I enclose a cheque/money order for $

payable to Next Media Pty Ltd OR Charge my credit card:

Mastercard Visa American Express

Name on Card

Expiry Date / CVV:

Cardholder’s Signature

SYDNEY (02) 9901 6111TOLLFREE 1300 361 146

SUBSCRIPTIONSPO BOX 3355

ST LEONARDS NSW 1590

MYMAGAZINES.COM.AU

W

REVIEWED

September/October 2016 | $9.99 | www.avhub.com.au

WE REVIEWDYNAUDIO’S NEWEST

BUDGET-PRICED FLOORSTANDERS!

Dynaudio Emit M30Loudspeakers

Bel Canto eOne DAC2.7DAC/Preamp

Parasound HaloIntegrated Amplifi er

Lavardin ITIntegrated Amplifi er

Elac Debut B6Loudspeakers

Mitchell & Johnson HP1Headphones

Audio-Technica ATH-SR5BTHeadphones

WIN A HI-FI SYSTEM VALUED

AT $5,440!

SUBSCRIPTION OFFER!

AHF Sep16_001 Cover.indd 1

8/19/2016 2:16:31 PM

INCLUDES HOME CINEMA & HI-FI LIVING SPECIAL EACH YEAR

Please provide phone or email in case of delivery issues

14 ISSUES (2 YEARS) $109 SAVE OVER $30 7 ISSUES (1 YEAR) $59 SAVE OVER 15%

YES! PLEASE SEND ME A SUBSCRIPTION TO AUSTRALIAN HI-FI

Yes, you can read some of our reviews in full on

AVHub.com.au. You can now swipe your way through

every page of Australian Hi-Fi on your iPad or Android

tablet, (or computer) using our snazzy Digital Issues.

But there’s nothing like the proper print edition, landing

in your letterbox sealed in shiny cellophane, ready for

you to read at your leisure, at full size, in

the order we intended, in the bath, if you like.

Get every issue of Australian Hi-Fi the way it should be.

SUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBESUBSCRIBEANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDANDSAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!SAVE!

HF Jul15_000 House Subs.indd 3 10/26/2016 2:30:55 PM