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MM/MC PHONO PREAMPLIFIER

Vietnam War, but the Iroquois [named after a tribe of native North American Indians] were used primarily as gunships, escorting the larger Chinooks.) A little googling revealed that Boeing named its Chinook helicopter after a small tribe of native North American Indians who were located in the North-West of America and had the unusual habit of de-termining their social hierarchy by the means of fl attening the heads of newborn babies by tying a board tightly across the top of their head, which would result in the skull becom-ing malformed. The resulting ‘fl at-headed’ children were at the top of the Chinookian social hierarchy, ‘above’ those Chinooks with round, unfl attened heads. However, all this googling proved to be a wild goose chase, be-cause Eveanna was actually thinking about a fi sh when she named her phono stage… spe-cifi cally the Chinook salmon (Oncorhynchus Tshawytscha) which is the largest species in the Pacifi c salmon family. This is why her advertising slogan for the Chinook is: ‘Don’t let this one get away! Hook a Chinook!’

Anyway, fi sh, helicopter, and Indian tribe with fl attened heads aside (though I must add one other piece of trivia, which is that at the height of the Vietnam War, the US had more helicopters in Vietnam than existed in the rest of the world!), Manley’s Chinook is

You’ve got to hand it to Eveanna Manley, head honchess at Manley Laboratories. She’s not one to shy away from a challenge—and or let

commercial sensibilities get in the way of her pursuit of the ultimate sound. So not content with deciding to specialise in the manu-facture and production of valve amplifi ers, which most marketing experts would con-sider a ‘niche’ market, she’s now gone even more ‘niche’ and produced a valve phono pre-amplifi er. But what a phono pre-amp it is! It’s essentially a stripped-down version of her Steelhead, which sells here in Australia for $11,499. But if you’ve already peeked at the information panel on the opposite page, you’ll see that the Chinook sells for just $2,999. Yep, that’s pretty high for a phono pre-amp… or at least that’s what I thought until I heard it!

THE EQUIPMENTI was rather taken by the model name Evean-na gave to this model, as I immediately asso-ciated it with the Chinook CH-47 medium-lift helicopter manufactured by Boeing that was the standard medium-lift chopper used throughout the Vietnam War. (Most people associate the Bell UH-1 Iroquois helicopter—commonly known as the ‘Huey’—with the

a straight-forward MM/MC phono preamp that uses the triode sections of a 6922 valve in combination with a completely passive RIAA equalization network which then links to another 6922 dual triode valve used as an output driver. Manley Labs claims that the valves are in a ‘White Follower’ confi gura-tion and promotes this circuit design with the slogan ‘no wimpy cathode followers here’… which confused me somewhat because the so-called ‘White Follower’ circuit developed in the 1940s by the famous inventor E.L. White (and used in all output transformerless power amplifi ers) is in fact a cathode follower circuit. I can only guess that she means that due to its super-low output impedance, it’s not a ‘wimpy’ circuit! (And, as you’ll discover, if you read the test results, this is certainly the understatement of the year!)

There’s nothing on the front panel except for the old-fashioned back-illuminated ‘Manley’ logo (which for some reason always reminds me of a Coca-Cola sign) and a single internally illuminated power switch. How-ever, as my regular readers will expectof me, I can fi nd fault even with this, and the single fault is that when it’s pressed in, it doesn’t sit below the level of the front panel, despite already being recessed into a small depres-sion on the front panel (it sits proud by about

Manley Chinook

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Manley Chinook MM/MC Phono Preamplifi er

cartridge will be the fi rst to suffer, plus you’ll get increased distortion, a lower signal-to-noise ratio and, perhaps most importantly, quashed dynamics. If you’re currently using a turntable and your phono preamplifi er isn’t adjustable you may already be experiencing all these limitations.

As you can see, the Chinook has a rack-mount face-plate. Why? I’m not exactly sure. Few audiophiles use standard commercial racking, so I can only assume that Manley Labs thinks the Chinook will be adopted by professional recording studios. The only thing contradicting this theory is that the Chinook does not have balanced outputs, which would be essential for studio use. If Manley is indeed intending that the Chinook be used in professional situations, it should defi nitely add balanced outputs via XLR. The front plate is 483mm wide and 89mm high. The unit itself is 285mm deep including the protrusions on the rear panel. It weighs 6.8kg. And, like all Manley’s products, the Chinook is built in Chino, California, in Manley’s own premises.

IN USE AND LISTENING SESSIONSSwitch the Chinook on and the front-panel pushbutton glows a bright blue to show that power is available, so it glows all the time the unit is plugged in. I found this a tad off-putting. When a component is in stand-by mode, I’d prefer something a little more muted. Press the button in and the Manley Labs logo glows a soft white (it’s backlit by LEDs), but the blue colour of the button doesn’t change at all. After approximately 30 seconds, there’s a ‘click’ sound from the left end of the Chinook and the Manley Labs logo lights up very brightly to show that all systems are go.

When connecting the Chinook, do pay attention to which of the two

MANLEY CHINOOKMM/MC PHONO PREAMPLIFIER

Brand: Manley LaboratoriesModel: ChinookCategory: Phono PreampRRP: $2,999Warranty: Five Years/Six Months*Distributor: Syntec International Pty LtdAddress: 60 Gibbes Street Chatswood NSW 2067

1800 648 628 (02) 9910 6700 (02) 9910 6710 sales@syntec.com.au www.syntec.com.au

(*On valves and badge lamps.)

Readers interested in a full technical ap-praisal of the performance of the Manley Laboratories Chinook Phono Preampli-fi er should continue on and read the LABORATORY REPORT published on page 114. Readers should note that the results mentioned in the report, tabulated in performance charts and/or displayed

using graphs and/or photo-graphs should be construed as applying only to the specifi c sample tested.

Lab Report on page 114

• Extraordinary sound• Adjustment options• Superb dynamics

• No balanced outputs• Front panel button• Screw removal

LAB REPORT

1mm). Tiny thing, I know, and completely petty, but in the pursuit of perfection…

All the action (or nearly all the action) takes place on the rear panel, where there are banks of DIP switches for adjusting the input resistance and capacitance so you can exactly match the requirements of your particular phono cartridge and cables. The other adjust-ments you can make are internal, where you have to lift the lid in order to alter the gain of the Chinook to accommodate either moving coil (60dB gain) or moving magnet (45dB gain) cartridges. I have a few complaints with this too. Firstly, Manley hasn’t exactly made it easy to get the lid off. There are no fewer than eight screws to get out, and they’re rather shallow (Philips #1) head types. I think hex-head screws would be superior (but admittedly would not fi t as neatly as the ones Manley is using). Once you get the lid off, I didn’t fi nd the instructions on how to set the switches were particularly clear, but there are only four switches and only two settings, so you can’t really go wrong. And, if you do, no harm can result. The fact I found the instruc-tions for setting gain ambiguous is most in-teresting because the instructions on how to set the rear panel DIP switches were so clear and unambiguous—and if you don’t get it, there’s a huge diagram showing all the switch settings and the resulting values. Curious.

It’s just as well the instructions are clear, because you can choose between 32 different resistance settings, from 26Ω to 47kΩ and 7 different capacitance settings, from 50pF to 350pF. These will cover just about every phono cartridge/cable combination I’ve ever heard of.

Why should you bother about getting the matching right? Basically because if you don’t you won’t be extracting the best performance from your phono cartridge… no matter how good—or expensive—it is. If you have a mismatch, the frequency response of your

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Manley Chinook MM/MC Phono Preamplifi erON TEST

was once I started listening, because although my own gear is perfectly matched to my cartridges, substituting the Chinook into my system gave an improvement I would not have thought possible. The improvement was not in frequency balance or lower levels of distortion, but in dynamics. Crescendos leapt from the vinyl in a way they hadn’t before, and transients became more sudden, more displacing, and somehow more visceral. I also fancied that the extreme highs became airier, even though I don’t think I was hearing more high frequencies than I was previously. Perhaps this is a subtle difference in the RIAA equalisation. Manley’s literature points out that the Chinook is unusual in that it in-cludes a fourth time constant at 3.2uS to ex-tend high-frequency response above 20kHz, to ensure that it’s fl at out to 50kHz rather than rolled off above 20kHz. The difference the Chinook made to my vinyl version of Dark Side of the Moon was palpable. Whereas the newer SACD version had previously taken over as my favourite ‘sound’ of this performance, the Chinook restored the vinyl version to its rightful place. The same was true of Emerson, Lake and Palmer’s Tarkus, which is for my money one of the greatest rock albums ever recorded. The complexity and depth of the music is breath-taking. I was thrilled to hear earlier this year that ELP will be re-issuing its complete discography. The project was due to start three months ago

(April 2012), but so far, nothing. I can only wait in hope. If you’re unfamiliar with ELP, I’d recommend picking up a CD (or if you can, an LP!) of ‘The Best of Emerson Lake and Palmer’ which contains their best-selling (and most accessible) works. If you fi nd you’re into it, then move on to Tarkus!

CONCLUSIONAlthough the Chinook may share most of the circuitry of the Steelhead, it’s not a Steelhead in terms of convenience, and it doesn’t quite have the fl exibility of the Steelhead… though it’s not missing a lot. Eveanna Manley says ‘the Chinook is really designed for music lovers, not the switch tweakers’. Ken Kessler is a great fan of the Steelhead, and is on record as say-ing that it was ‘the best-sounding phono stage I’ve ever experienced’… though Kessler did go on to say that what Manley was asking for the Steelhead was ‘nut-case money’! I can say that while I haven’t heard the Steelhead, I am prepared to say that the Chinook is by far and away the best phono preamp I’ve ever had the pleasure to hear and, by virtue of its valve topology, offers levels of headroom that I don’t think could be matched by any solid-state phono stage. It’s not inexpensive, but then again it’s nowhere near ‘nut-case’ money. In fact if you want the best phono preamp around that’s not a Steelhead, my opinion is that the Chinook is a defi nite “gimme”. greg borrowman

gold-plated RCA connectors are the phono inputs and which are the line outputs. The rear panel of my sample had the outputs clearly identifi ed, but the inputs weren’t quite so clearly identifi ed: I think that putting 47kΩ in front of the words ‘phono inputs’ detracts from the clarity of the message.

At one stage when I swapped over cartridges and had to use the internal DIP switches to change the gain from 45dB to 60dB I realised that there might be method behind Manley Lab’s seeming madness in making the inside of the pre-amplifi er so inaccessible. The method is that by the time I’d fi nally removing the last of the eight screws holding the lid in place, around 15 minutes had elapsed, which was suffi cient time for the capacitors inside the amplifi er to have completely discharged, meaning that the circuitry was safe if I accidentally touched it. Sensibly, Manley makes special note that you should disconnect everything and wait 15 minutes before removing the top of the Chinook. It even mentions out the old elec-tricians’ rule that you should only ever use one hand when reaching into the enclosure or touching any parts and that you should keep your other hand ‘in your pocket.’ The reason for this advice is that if you follow this advice—and you most certainly should!—it’s unlikely that you will be in danger if something completely unexpected happens. The Owners Manual goes on to give practical advice on how to remove and re-insert valves, how to work out if you have a ‘bad’ valve and advice on compatible valve types should you not be able to get an exact replacement in your locale. One thing Manley does not men-tion directly (although it does so in passing) is that it’s better if you don’t try to move the Chinook while the valves are still hot. If you need to move it for any reason, turn it off and then wait until it’s completely cold.

Most of my listening was done with a Garrott-tipped and tweaked Shure Era IV moving-magnet and Ortofon SPU moving-coil cartridges. In the process of tweaking the DIP switches to get everything perfect, I discovered that the switching process is completely electrically silent—there are no annoying (and potentially damaging) clicks and pops. Wonderful! Even more wonderful

LAB REPORT ON PAGE 114

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114 Australian

LAB REPORT Manley Chinook MC/MM Phono Preamplifi er

Manley Chinook Phono Preamplifi erTest Measured Result Units/Comment

Frequency Response @ 1 volt o/p See Graph –1dB

Channel Separation (dB) 88dB / 85dB / 75dB (20Hz / 1kHz / 20kHz)

Channel Balance 0.08 dB @ 1kHz

THD+N 0.12% @ 1-volt output

Signal-to-Noise (unwghted/wghted) 68dB / 86dB dB referred to 1-volt output

Input Sensitivity (CD Input) 5.5mV for 1-volt out

Phono Overload Margin 35dB at 1kHz

Power Consumption 1.13 / 43.89 watts (Standby / On)

Mains Voltage Variation during Test 242 – 252 Minimum – Maximum

Heatsink Temperature (Degrees C) 51 Above output valve

TEST RESULTSNewport Test Labs measured the frequency response of the Manley Labs Chinook using a hand-built precision inverse RIAA network. The result is shown in Graph 2. You can see that the frequency response extends from 20Hz to 30kHz ±0.2dB, which is ‘way better than Manley’s specifi cation and incredibly accurate. And when you look at the graph, you can see that most of these variations occur above 1kHz. Between 30Hz and 1kHz, which takes in almost all of the important midrange, the response is virtually a fl at line. Note, too, that the 30kHz upper limit is a measuring limit with this test: as you can see from the graph, the Chinook is showing no signs of rolling off, so I can well believe Man-ley’s claim that it extends to beyond 50kHz. Below 20Hz the response rolls off, but not ex-cessively, so that it’s only 1dB down at 10Hz and 5dB down at 4.8Hz. Channel separation was measured at 88dB at 20Hz, 85dB at 1kHz and an incredible 75dB at 20kHz. This is superb performance, and far in excess of the requirements for any phono cartridge. Also exceptional was channel balance, at 0.08dB.

Harmonic distortion is shown in Graph 1. You can see that there’s only a second harmonic component at –85dB (0.005%) and a third harmonic at –81dB (0.008%). (Ignore

the spike up just below 16kHz, it’s unwanted breakthrough into the measuring equipment from a nearby CRT). The noise fl oor is very low. From around 500Hz upwards, it’s more than 100dB down. You can see that there’s a single spike down at 50Hz that’s around –58dB down, but then the harmonics of this are more than 80dB down. Overall, Newport Test Labs measured THD+N at 0.12%. As for the signal-to-noise ratio, Newport Test Labs measured the wideband S/N of the Manley Chinook at 68dB unweighted and 86dB A-weighted, referred to a 1-volt output. Manley doesn’t state standard S/N fi gures, preferring to quote ‘dynamic range at 1kHz’ and you

can see from the graph that at 1kHz, Newport Test Labs’ graph shows this to be around 105dB which is about midway between Manley Labs’ two claims of 91dB and 107dB, as Manley refers its 0dB levels to distortion levels, rather than signal levels.

Graph 3 shows the transfer function of the Manley Labs Chinook. Obviously the need for the graph to span a range of 60dB in order to fi t the function prevents close exami-nation of the curve itself, but a separate xls fi le print-out of the values confi rmed Man-ley’s claims for the accuracy of the transfer function. Gain levels were also spot-on. You certainly won’t have to worry about overload-

ing the input, because the Chinook can accept a massive 309mV before it will overload, giving an overload margin of a staggering 35dB.

Power consumption was moder-ate. When operating, the Chinook will pull just over 40-watts con-tinuously from your mains power supply. In its stand-by mode, con-sumption is a shade over 1-watt, so you can leave it in standby mode indefi nitely with impunity. When it’s operating, the Chinook runs quite cool thanks the perforated top and sides. The section of metal chassis right over the output valves measured at 51°C. Steve Holding

CONTINUED FROM PAGE 28

You certainly won’t have to worry about overloading.The Chinook can accept a massive 309mV, giving an overload margin of 35dB! 0.00 Hz 4000.00 8000.00 12000.00 16000.00 20000.00

-140.00

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Graph 1: THD at 1kHz, 1-volt out, referenced to 0dB. [Manley Laboratories Chinook Phono Preamp]

Newport Test LabsTest LabsT

10.00 Hz 100.00 1000.00 10000.00

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Graph 3: RIAA Equalisation Transfer Function [Manley Laboratories Chinook Phono Preamplifier]

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10.00 Hz 100.00 1000.00 10000.00 30000.00

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Graph 2: Frequency response (RIAA equalised). [Manley Laboratories Chinook Phono Preamplifier]

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