Building Hypex Nilai500 DIY Class D Amplifier Kits

Nilai is a city in the Seremban, Negeri Sembilan region of Malaysia. It It is the place where the latest Hypex modules are manufactured, and the origin of the moniker of the latest and greatest Hypex modules to hit the DIY market. Nilai is a cut above NCore, which was already class-leading, and better even than NCoreX – the new revision of Core that OEM customers are getting for integration into their products. Hypex wanted to do something special for the DIY market, a cornerstone of Hypex’ business for over a decade. The DIY market is the first to get access to the new Nilai class D technology which Hypex claim offers 10x better performance than the older NCore tech.

I’ll explore Nilai in greater detail in a future article. For now I have my hands on two of the new mono amp kits, and wanted to share a build article with you. Since I built the NC400 mono amps, which have been mainstays in my reference system for some time, I’m often asked whether anybody can really build their own amplifier without prior experience, expensive test equipment, or a workshop full of tools. My answer is always the same. Can you assemble a puzzle? If so, you can put together a Hypex amplifier.

Box Sleeve Hypex Nilai 500

We have here a pair of the mono kits. A stereo kit is also available, which has a larger enclosure and implements a pair of mono modules with a single power supply. The components are the same and this guide will apply to both, though the layout will obviously differ slightly. The stereo kit comes at a price advantage, but the mono kit gives you more power, better flexibility, and would be my choice every time at this level.

The packaging consists entirely of recycled cardboard, with each component individually bagged and neatly arranged in the box. The power supply and module occupy most of the top layer, along with several small bags of screws and cables. You get an IEC power inlet with T6 fuse, a power switch, input/trigger board, front button and LED board, hex and Torx keys and some instructions. Lastly there are the components that make up the enclosure – feet and screws, side extrusions, base and top panels and the front and rear panels, with metal brackets for the former.

Opened Box Hypex Nilai 500

The wiring is crimped, tinned and soldered for you as necessary, and everything you need is included besides a 3.5 mm flat screwdriver and 5.5 and 7 mm spanners, nut spinners or pliers to tighten the earth nuts and the nuts on the speaker terminals. A simple pair of long-nose combination pliers will do just fine. It helps immensely to have a plastic ice cube tray or pill box to hand to organise the screws and washers before you start. And set aside an hour or two if you’ve never done this before, though they can easily be built inside of 30 minutes.

Screws Laid Out In Tray Hypex Nilai 500

With everything unboxed, locate the power supply and its base plate. Using the small silver screws provided, affix the power supply to the plate with the small round protrusions pointing toward the circuit board. It only goes 1 way round due to the screw positions. 

Position the power supply onto the base of the enclosure. The side of the board that doesn’t contain any connection sockets faces the front of the amp, closest to the edge of the enclosure. It’s helpful to thread a screw up from underneath to help you align the first hole of the base plate. Secure the power supply with 5 black screws through the countersunk holes on the underside of the base.

Underside Of Base Showing Power Board Fixing Holes Hypex Nilai 500

Connect the wide ribbon cable in your cable pack to the connector on the side of the power supply, as it will be difficult to access with the sides of the enclosure in place.

Ribbon Cable Fitted To Main Board Hypex Nilai 500

Next locate the amplifier module. Position the module on the enclosure base with the cable terminals closest to the side of the enclosure where the power supply cable you connected previously is pointed. This positions the gain jumper and input connector as close as possible to the back of the amp. Screw the module into place through the underside of the enclosure with the four remaining black screws.

Main Board And Power Board Fitted To Base Hypex Nilai 500

locate the two side extrusions, the feet, four longer countersunk screws and four small spring washers. Discard the screws that are found in the bag with the feet, these are not required. Offer up a side of the bottom panel to one side extrusion. Place a spring washer onto the screw, thread the screw through each foot, through the small hole in the bottom of the side extrusion, and into the tapped hole in the bottom panel. Repeat for the opposite side.

Next assemble the back panel. Remove the speaker terminals from the black mounting plate and discard it. Remove the locating rings from the terminals and place them into the outer side of the back panel, aligning the protrusion on the ring with the notch cut into the terminal hole.

Removing Speaker Inputs From Plastic Plate Hypex Nilai 500

Fit each terminal with the cable entry points facing downward at a 45-degree angle, pointing away from each other. Thread the remaining plastic washer and the nut onto the rear of the terminal and tighten them down using a 7 mm nut driver, spanner or pliers.

Speaker Plugs Fitted Rear View Hypex Nilai 500

Note: you can install the terminals in any orientation you see fit. The orientation shown in the instructions may present you with a challenge if you use unusually thick cables or large spade connectors. In that case, fit the terminals with the cable entry holes pointing straight up, or upwards at an angle. Make sure to position the terminals correctly – the black (negative) terminal goes closest to the power inlet.

Fit the speaker cable to the terminals. Back out the grub screws on each side of the rear terminal post with a 3.5 mm flat screwdriver, push the tinned end of the speaker wire into the end of the post as far as it will go, and evenly tighten the screws to secure the cable. Connect white to the positive (red +) terminal and the black to the negative (black -) terminal.

Speaker Plugs Fitted Inside View With Cable Installed Hypex Nilai 500

Locate the IEC inlet socket, and fit the fuse to the clip at the front of the fuse drawer before pushing it into place. You can store the spare fuse in the spare hole inside the fuse drawer for safe keeping. Orient the back panel of the enclosure so that the writing is the correct way up and facing you. Push the IEC connector into place (it’s a tight fit) with the fuse drawer at the bottom. Do the same with the switch, with the spade connectors furthest from the edge of the panel.

Power Point And Switch Fitted Rear View Hypex Nilai 500

Install the wire with a spade connector at each end between the live terminal of the IEC connector (bottom connector, directly behind the fuse drawer) and connect the other end to the terminal of the switch furthest from the edge of the panel. Connect the wire with a spade at one end and a ring at the other to the earth terminal of the IEC connector, which is the terminal at the top. Locate the main power cable and connect the live (brown) wire to the other terminal on the switch, and the neutral or return (blue) wire to the remaining terminal of the IEC inlet.

Power Point And Switch Wiring Inside View Hypex Nilai 500

Fit the input board by slotting the XLR connector into place (careful of the release button) and using the two self-tapping screws provided.

Input Board Fitted Rear View Hypex Nilai 500

Connect the smaller ribbon cable to the connector on the side, and the input cable to its socket on the same board.

Input Board Fitted And Ribbon Wire Inside View Hypex Nilai 500

Bring the panel to the amp, and connect the rest of the wiring. Attach the speaker cables to the terminals on the amplifier using the provided Allen key. The cables are pre-fitted at 1 end with spade connectors which fit the gap between the cable clamp and the top of the terminal when the screw is tightened. Don’t over-tighten these as they can strip; snug is fine, as long as the cable is held in place. Make sure to connect the white wire to the LS+ (positive) terminal and the black wire to LS- (negative) or your loudspeaker phasing will be incorrect.

Connect the input cable to its socket on the amp, and the larger ribbon cable from the power supply to its socket on the front of the input board. Connect the main power cable to the matching 2-pin socket on the power supply. Connect the main power cable between the power input on the amplifier and the power socket on the power supply. The instructions indicate that the output socket in the middle of the row of connectors is to be used with a mono configuration, but it probably doesn’t make a difference. It’s important to twist the already twisted pairs of the power supply cables together though to minimise interference.

Overall View Of Inside Wired Up Hypex Nilai 500

All of the connectors in the amp are designed to only fit in 1 orientation. They might require some pressure to plug in, but don’t force anything. The power and input signal connectors have small clips that will click into place when the connectors are fully pushed home.

Join the rear panel to the amplifier. Locate four black screws and four of the larger spring washers. Thread a screw through the back panel, and install a spring washer behind, with the dome of the spring washer facing outwards. Locate the screws into the holes in the side extrusions and tighten them with the Allen key provided. I recommend starting with 1 screw and screw it in just enough so that the thread catches, then install the rest of the screws in the same manner and tighten everything down.

Using the fifth black countersunk screw, nut, toothed washer and spring washer provided, connect the ring of the earth cable to the bottom of the chassis. The toothed washer goes between the chassis and the ring, then the spring washer, then the nut. Tighten this securely with a 5.5 mm spanner, nut driver or pliers.

Earth Cable Screw Washers And Nut In Order Hypex Nilai 500

Fit the front panel mounting brackets using the remaining silver screws and spring washers.

You’ll find you have 1 plug left hanging, which goes to the power button and LED board. Connect this, locate the board into its cutout on the front panel, and screw it into place with the two pan-head screws and washers provided.

Before you fit the top, verify the location of the gain jumper on the amplifier board. There are three gain settings – high, medium and low, with a medium gain being the default. It’s probably the setting most users will stick with, but you may need to adjust this depending on the preamplifier or DAC you will use to drive the amplifiers. If you’re driving them directly from a DAC, for example, and using the DAC to control the system volume, you may find a higher gain is required to drive the amps to full power or to the desired volume. I recommend setting them to the medium setting and adjusting them later if necessary. For now, make sure they’re both set the same.

Gain Jumper Hypex Nilai 500

Locate the top panel and slide it into the slots in the extrusions. You may find this a tight fit, and you may have to slightly loosen the screws holding the back panel and feet to allow some movement in the side extrusions to get the panel to slot into place. The manufacturing tolerances in this enclosure are extremely tight.

Top Plate Fitted Hypex Nilai 500

Then, hook the front panel over its brackets, and push it against the face of the chassis until it locates fully.

Front Plate Fitted Hypex Nilai 500

Flip the amp over and using the 1.5 mm hex key provided install the two retaining grub screws into the bottom edge of the front panel.

Front Plate Grub Screws Fitted Hypex Nilai 500

And that is all that is required to assemble your amplifier. Connect up some speakers, plug in the power and an input signal, switch on and enjoy. If you don’t see any action from the front LED, check the rear switch is in either the upper or lower position. If you get no power at all, double check that you installed the fuse correctly and if you did, remove the front, slide the top away and check your connections.

In the next instalment I will detail the build of the new Hypex preamplifier kit. In future articles we will look at both units in more detail, objectively and subjectively, compare them to the NC400. I might also explore possible tweaks and modifications, and there are add-ons for the preamplifier to be introduced in due course. There are exciting things happening at the moment.

Quick build summary:

Building one of these amps can be achieved in just 15 steps:

  1. Mount power supply to power supply mounting plate, six silver screws.
  2. Mount power supply to base of enclosure, five black screws.
  3. Mount Nilai 500 amp module to base of enclosure, four black screws.
  4. Connect larger ribbon cable to power supply.
  5. Mount side extrusions and feet, four countersunk screws & spring washers.
  6. Mount speaker terminals to rear panel (7 mm nuts) and connect speaker cable (3.5 mm flat screwdriver).
  7. Mount IEC socket, install fuse and mount power switch. Connect power cables.
  8. mount input board, connect smaller ribbon and input cables.
  9. Connect speaker and input cables to amp, power cable to power supply board, wide ribbon to input board, power cable to amp module.
  10. Mount rear panel to enclosure.
  11. Install earth cable to enclosure base, black screw, toothed washer, spring washer, 5.5 mm nut.
  12. Mount front panel brackets, four silver screws, four spring washers.
  13. Connect button board to cable and install into front panel, two pinhead screws.
  14. Slide top panel into place.
  15. Install front panel, 2 grub screws.

By Ashley

I founded Audio Appraisal a few years ago and continue to regularly update it with fresh content. An avid vinyl collector and coffee addict, I can often be found at a workbench tinkering with a faulty electronic device, tweaking a turntable to extract the last bit of detail from those tiny grooves in the plastic stuff, or relaxing in front of the hi-fi with a good album. A musician, occasional producer and sound engineer, other hobbies include software programming, web development, long walks and occasional DIY. Follow @ashleycox2


  1. Hi Ashley,

    My name is Rex Roy, writing from Vancouver, British Columbia.
    I’ve been following your website and enjoying your reviews for quite some time.

    I am very pleased (and excited) to see your two recent articles, in which you assemble the new Hypex Nilai kits.

    Looking forward to reading your comments on how they sound/compare to your current reference pieces.

    In particular, I do hope you will have the opportunity to compare the power amps to the Musical Fidelity M6PRX,
    and the preamp to the Musical Fidelity M8SPRE.

    Best regards,
    Keep up the great work,
    R. Roy

    1. Thank you Rex for your comments and kind words on my reviews. I actually no-longer own the reference pieces you mention. My reference preamp currently is a Topping A90D with the additional input expander box, and my amps for some time have been Hypex NC400 monoblocks. What I will say is that the Hypex amps, even the NC400s, sound similar to the Musical Fidelity M6 PRX in that they have apparently limitless power, but they are clearly much quieter. The Hypex preamp is extremely quiet, much more so than the M8 but not as much as the Topping, and it is also quite limited in terms of connectivity which is something I will expand upon in the review, hopefully shortly. There is certainly more to come, so stay tuned!

      1. Hi Ashley,

        Rex Roy here.
        A year(!) has gone by since you published the above posts about
        the Nilai builds – amps and preamp.
        I’ve been checking your site regularly to find out what your ‘further thoughts’ might be on these products, but so far nothing.
        Are the mono power amps all that you thought they would be?
        I am using a stereo Hypex NCx500 module in an amp built by Dylan at Buckeye. I have read however that the Nilai amps might be slightly better.
        I’ve also read that the Icepower AS1200 board is outstanding.

        I’m also looking for a simple, highly transparent preamp that I can use as a reference, preferably with two XLR outputs, which the Nilai has, and very low output impedance, which the Nilai also has (in the neighborhood of 44 ohms I believe).
        Any thoughts? Is the Topping still high on your list of preamps?

        Keep up the good work,
        Best regards,
        Rex Roy

        1. Apologies, I’ve been delayed in publishing full reviews. I wanted to use them for a period of time and I was hoping there would be some add-ons for the preamp by now but they haven’t been released yet. The Nilai500 amps are incredible and are now my reference amps. I cannot imagine a better amplifier. They take the input source, increase the gain and drive any loudspeaker I have used. As for the preamp, I use a TOpping A90D with the EXT90 input extender. It is transparent, clean, quiet, ruler flat and low distortion, so it’s perfect for the Hypex amps. It is not perfect. The user interface is a pain to use, there is only 1 balanced output, the balanced input impedance is very low which can affect some devices (mainly older devices) if their output stages can’t drive a low impedance load, there are only 2 single-ended inputs, and the remote is dreadful. The Hypex Nilai preamp is transparent, low distortion and very clean, with a lovely user interface, but it has limitations. It delivers only 4 volts RMS input and output so there isn’t much headroom particularly on teh input side, it is likely the preamplifier will be driven to clipping before any amplifier will. It only has 1 balanced input (ridiculous) and 2 single-ended inputs (not enough). It doesn’t have as much headphone output pwoer as the topping, if that matters to you.

          I don’t think that there is a ‘perfect preamp’ on the market. In fact I think the Topping and the Hypex are probably he 2 best solutions out there at the moment, which is a bit of a shame. There is an analogue preamp in development but it is in the early planning stages. Unfortunately good analogue preamps are something of a rarity these days.

          1. Hi Ashley,

            Thanks so much for taking the time to formulate such a considered and detailed reply. Very clear,
            and very helpful. Since I started reading your reviews a few years ago, I find that your general approach to audio and the reproduction of music has a great many points of commonality with my own approach.

            Re the above remarks: I too have been searching for a high quality preamp for quite some time, and have tried all sorts of them, and they almost all fall short
            in at least one parameter or another.

            I would be very interested to find out, when the time is right, what you are referring to when you mention
            “an analogue preamp in development”. Please keep
            me posted if at all possible.

            Thanks again for your help,
            Best regards,
            Rex Roy

  2. Way to go for knocking that one out of the park. You know your shit.

    Having run afoul of that imbecile/asshole Michael Fremer at Stereophile and a few more of his ilk, I’m always heartened to see real content from users/reviewers that truly understand audio and are publishing reviews that aren’t presenting the “This Sounds Good To Me” bullshit that 90% (or more) of the audio sites publish now.

    Count yourself amongst those who are not the idiots that push on-line reviews who have no understanding of the tech they are reviewing. You did a great job.

    I very jealous. I’m assuming you got two monoblocks so, damn aren’t you lucky! You now have two of the best amps ever made.

    Hey, if you got Purifi monos or a Benchmark AHB-2, you’d still have fantastic amps that were 99.5% as good.

    If everything shakes out with the supplied specs matching independent measurements, the Nilai will be the best audio amplifier ever. It will mean that it will have no “sound” since all of its distortions, noises and non-linearities will be below human audibility by a few orders of magnitude.

    Morons like Michael Fremer think their hearing is perfect. This is their arrogance on display. They like vinyl, tube amps and $4,000 power chords. All of that is bull shit. This amp is not.

    The truth is that truly good electronics had surpassed human hearing over 10 years ago. This amp takes it even further. The most fantastic thing is that Benchmark, Purifi and Hypex have made the best amps in the world and regular people can afford them.

    Audio reviewers don’t want to hear that the best amps, pre’s & pre/pros no longer have a sound. Other than confirming their specs through measurements, audio sites needn’t have some jackass giving their perspective. That means, of course, that the jackasses are losing money or just straight out of a job.

    (Had a reviewer at magazine tell me that my Emotiva XMC-1 pre/pro was a pice of shit… I then reminded him that his magazine did comprehensive measurements and named it a product of the year…never heard back from him)

    The only area left for true improvement is speakers. That path is blazed by pro monitors and hi-fi companies like KEF, Legacy, Meridian, Kii, Dynaudio, etc. DSP is the answer. Yes, new transducers will make marginal improvements, but active DSP is the future.

    Speakers are the only area left for subjective audio reviewing. You might say, “But what about DACs?”

    Honestly, if you are talking about cheapo stuff that you’ll hook up to a computer’s USB, sure. I’m doubtful that any properly designed and constructed DAC, pre/pro or integrated will elicit any sound quality difference that a human can hear on most or any music.

    This is where current audio reviewing breaks down. Unlike 30 years ago, publications and sites make no effort to research whether current hi-fi DACs (let’s say $1K or more) even have a “sound” that humans can demonstrably hear in double blind tests. Sorry for bringing up science and statistics.

    I’ll accept that the inexpensive ones will have more noise and a bit more low level grunge (measured and heard it). I’ve worked as a musician/producer/engineer in the past. I know the drill.

    Bottom line: any audio equipment that measures to have linear phase with distortion & noise around or below -130dB is perfect to the human sense of hearing.

    Humans can’t tolerate average sound levels of 105dB for much more than an hour without hearing injury. The best studios and their microphones have self noise of around 15dB. An anechoic chamber may have a quiescent noise level of around 5dB.

    The best hi-fi listening room that you’d want to live in has background noise of 25-30dB. While we can hear into the background noise, it won’t be very deep at the limits of our hearing.

    So, at best, in optimal conditions, our hearing has a dynamic resolution of about 90dB or so in a normal listening room in a home. Below the threshold is too low to hear and above is our ears overloading. Ever been to a rock concert where it starts to turn into a cacophonous din after an hour?

    Human hearing is neither infinite or even that great amongst other mammals.

    As Dirty Harry once said in a movie, “A man’s got to know his limitations.” Of course, this was this the final line after he killed the bad guy.

    Bottom line: people, for the most part, are fucking stupid. Dilettantes like Micheal Fremer and the rest prove this

    Audio recording & engineering is about either recording an acoustic sound as faithfully as possible or creating an musical landscape that is compelling regardless of its lack of true realism (a lot of my music uses synths and electric instruments). Audio reproduction is about taking that recording and playing it back as it sounded in the studio.

    It’s amazing how many “audiophiles” don’t want that. They want a “sound”. That is not hi-fi.

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