Enleum HPA-23RM Reference Headphone Amplifier

 Introduction

"Enleum" is a combination of the words "Enlightenment" and "Eum" (Korean for "Sound"). You may have heard of Soo In Chae's work under "Bakoon" which was a collaboration between Soo In (founder of Enleum) and Akira Nagai. 

Description

The HPA-23RM (the "R" and "M" being shorthand for Reference and Mobile) is a unique headphone amplifier with two different amplification circuits - a voltage, and current output stage. The voltage stage is a MOSFET output stage based on a simplified version of the JET2 bias circuit seen in the AMP-23R. The current output stage is derived from the HPA-21's bipolar transistor circuit. While this device is not something you would lug around on a regular basis, it is portable enough to be moved around and can be used on-the-go thanks to its built-in battery. Similar in size to a paper-backed novel, the Enleum measures 116mm x 164.5mm x 22mm and weighs 750 grams.

On the front panel, a toggle switch selects gain, while a recessed rotary knob functions as both a volume control and power switch. A 3.5mm socket is mated to the voltage stage, while a 1/4 inch socket is used for the current output stage. A row of LED lights indicate charge status, battery life and operation. 

The inputs are located on the rear panel, with a USB-C socket used for charging, and a pair of RCA sockets and a 3.5mm socket used for the input signal. There is no selector switch, so only one input may be used at a time. If the 3.5mm socket is in use, this is given priority over the RCA input. 

The current-output stage is capable of 1W of power, and half of that into the voltage output (into a 30 ohm load).   

 

In operation

Rotating the volume knob from its resting position to about 8 o'clock brings the unit into standby mode. The LEDs light up to indicate the battery level. The HPA-23RM uses a discrete resistor relay network to control the volume and further advancing the knob unmutes the unit, with an audible click as you move between each volume level. The manual advises you to bring the volume knob back to the standby position before plugging and unplugging headphones to avoid damage to the unit. 

The unit is specified to operate for up to 5 hours of use in voltage output mode, and 3.5 hours in current output mode, which matched my user experience. Thankfully, the HPA-23RM can be charged while in use.

Sound Quality

For the purposes of this review, I used the Enleum with an iFi Pro iDSD DAC as a source. To cover a variety of IEMs and headphones, I tried the Enleum with the Letshuoer S12 Pro IEM, Beyer DT-880 (250 ohm), Drop HD 8xx and the Audeze LCD2.1. 

As a starting point, Enleum recommends that the voltage output be used with IEMs / headphones that are sensitive, or have a varying impedance curve, while the current output be used with headphones that have a flat impedance curve such as planar headphones. This is not a hard rule, and Enleum does encourage you to experiment. Matching a headphone with a varying impedance curve with the current output does result in a frequency response that tracks the impedance curve, which could be either a good or bad thing depending on your objective. For example, the Drop HD 8xx has an impedance peak at about 100 Hz and a falling impedance in the high-frequencies. Listening to these headphones through the current output gives you added bass and attenuated high-frequencies. Unless you are seeking to alter the tone of your headphones, I found following Enleum's advice to give the best results.

Tonally, the Enleum has a slightly warm and organic midrange, while maintaining an airy and detailed treble. The real shocker is the tightness and power of the bass, which is quite impressive if you consider that this is a battery-powered device. On bright headphones like the Beyer and Drop, this does balance things out a bit, although the warm-sounding Audeze sounded great with the Enleum too. 

The Enleum is highly detailed throughout the frequency range and casts a wide and open soundstage, with a sense of dynamic freedom that eludes most headphone amps. From a performance point of view, the Enleum is easily at the very top, outperforming the headphone output stage of the iDSD DAC, or the Vioelectric HPA V281 that I owned in the past. In my view, the Enleum is really in its element when paired with planar headphones.  

The Enleum does have its weak points. Although there is a gain switch, using either the Beyer or Drop headphones on current mode was tricky, with the volume steps being too far apart. On the positive side, the discrete resistor volume provided precise channel balance even at very low volume levels or high-sensitivity headphones or IEMs. I would also have preferred for the voltage output mode to be paired with a 1/4 inch socket too. 

Battery life is a bit short to make mobile use practical and the repeated charging cycles will necessitate regular battery replacement. Thankfully, the Enleum uses a spring-loaded battery holder for its dual 18650 Lithium-ion batteries, which are widely available. Your unit shouldn't require a return home to South Korea for servicing, and battery replacement should be straightforward. 

Conclusion

Despite the high price tag, the Enleum rewards with top-level sonic performance. It is a must-audition for planar headphone users, and does a fine job with dynamic headphones too. Don't let the mobile moniker fool you though, this amp makes perfect sense for desktop use too - Highly Recommended.

A big thanks goes to Cornerstone Audio for making this review possible.

Price : S$ 4,200

Cornerstone Audio

444 Race Course Rd, S21888 (by appointment only)

E-mail : contact@cornerstone-audio.com  

Telephone : +65 8890 4885         

KZ xHBB PR2 In-Ear Monitor

Introduction

Knowledge Zenith (KZ) is back with a planar driver IEM tuned by HBB, the popular Youtuber who runs Bad Guy Good Audio Reviews. Priced at USD 45, this is aimed squarely at the budget planar market.

Description

Based on a single 13.2mm planar magnetic driver, the KZ PR2 is made from an alloy die-cast shell. The supplied 1.2m long cable is silver-plated and you can also order a mic version for USD 2 extra. The cable is nothing special - no chin slider, and the 3.5mm plug is not interchangeable. At least it's flexible and doesn't tangle up easily. The PR2 uses 0.75mm pins, so feel free to express yourself with a third-party cable of your choice. I ordered the version with the mic and the voice quality is quite decent and works well enough for conference calls in a quiet environment. 

Included in the box are four tips - one set of foam tips and three pairs of silicon tips in different sizes. There is no carrying case, or anything else fancy. 

The cut-away diagram on KZ's website shows a silver-plated diaphragm with seven N52 rubidium magnets on either side of the diaphragm.

Here is a picture of the measured response from KZ's website :-

Specified impedance is 15 ohms (+/- 3 ohms), and sensitivity at 94db (+/- 3 db). Well, planar drivers are hard to drive, and this one is especially difficult. Driven directly out of a computer or mobile phone headphone jack, the resultant performance is poor to mediocre at best. Apart from limited volume, music sounds strained and confused.  

Sound Quality

Bring proper amplification to the party, and the PR2 sounds great. Both an Aurender Flow DAC/headamp and a Questyle M15 dongle DAC had enough power to allow the PR2 to shine. 

Bass is especially impressive, with a tight and impactful quality. The tuning is neutral, with good and clean vocals and highs. Decay is good, although on the drier side. Staging and imaging are also above average, with good separation and layering. There is a touch of forwardness to the midrange though, which gives vocals a subtle presence boost. You also get speed and details galore, which is especially impressive given the low price tag. 

Tonally, this is one of the brighter-sounding IEMs on the market, with very little midbass and midrange warmth. You could use EQ to tune this IEM more to your liking, but the intrinsic character won't change that much.  If you prefer a warm and bassy IEM, you are better off with something else. 

In comparison to the Letshuoer S12 Pro (the other planar IEM in my collection), the PR2 is not quite as musical or fun to listen to. The S12 Pro has a much better cable, interchangeable connectors (including a 2.5 and 4.4mm balanced plug), and is easier to drive. The S12 Pro has a warmer and fuller balance, and better dimensionality. The S12 Pro also costs four times more than the PR2, and in my opinion, the performance gap between both is not that big. This gives a clear nod to the PR2 in the value stakes. According to HBB, the PR2 uses the same driver as the KZ PR1 Pro which is almost twice the price of the PR2. In short, you get a lot for your money. 

Conclusion

An outstanding bargain if you are a fan of its neutral tuning. The low sensitivity makes a good dongle DAC or headamp mandatory though - Best Buy.

Price - USD 45

http://kz-audio.com

WFH Special #2 - Creative Outlier Air V3

Introduction

Not a fan of wired headsets for your office conference calls? Consider true wireless in-ear-monitors as an alternative. Lightweight and comfortable, they are a more practical choice in tropical weather if you do not run air-conditioning. 

Apart from office use, they will be perfect for accompanying you for your exercise sessions, or travelling. This makes them an easy sell to the Minister of Finance at home. 

Description

The Outlier Air V3 ("V3") is the third-generation version of the Outlier Air - Creative's true wireless in-ear-monitors. 

The charging case remains at about the same size as the original Outlier Air ("V1") which means that it is bulky and clunky to carry around. Sharing the same footprint, the V3 case is slightly taller. You do get 40 hours of playtime though with 10 hours per charge, which is improvement over the 30 hour lifespan of the original model. The case may be charged via a USB-C port, or Qi-compatible wireless charging. Charging time via cable is between 2 to 3 hours.

The V3 uses Bluetooth V 5.2. Supported audio codes are AAC and SBC. Purists will be disappointed to note that aptX support has been dropped. Like the V1, the V3 is IPX5 certified for water resistance. 

The driver for the V3 uses a 6 mm bio-cellulose driver, which is a change from the 5.6 mm graphene-coated drivers used in the V1. 

The V3 case, fully loaded with earbuds weighed in at 76.6 grams, compared to 61.8 grams for the V1. The earbuds for the V3 are 5.3 grams in weight (per side), while the V1 are 5.1 grams. 

By default, the usual volume and play control functions, Siri or Google Assistant, as well as ambient and active noise reduction modes are accessible via touch control. However, you can also customise the controls via the Creative App. This App is also used to flash firmware upgrades and applying EQ settings.

Besides the Creative App, you will need to download the SXFI App to transfer your personal profile over to the Outlier Air. Music also has to be played through this App in order to enjoy SXFI. This is an inconvenience, especially if your music source is from a streaming service since the App supports playback of local music files only.  

Use, Fit and Comfort 

Taking the earbuds out of the case will put the V3 into pairing mode automatically. You also have the option of just using one side (useful for conference calls). I noticed that the earbuds would also squeal loudly when being returned to their case. I traced this to feedback from the microphones when either ambient mode or active noise reduction is being used. Alternatively, place the earbuds back in the case one at a time to avoid this. 

Fit will be subjective. The V1 with its larger shell, fitted my ears better and provided a better seal. The V3 felt less secure, and did not seal as well in my right ear. However, this can be easily remedied by changing out the tips to suit your personal preference. The V3 sat quite securely during exercise sessions, although I would feel less confident to use them for long runs. They were also comfortable enough to be used for long listening sessions.

Battery life was consistent with specifications and the V3 had no issue connecting with my phone placed about 6m away so long as line-of-sight is maintained. 

Sound

The V3 turned in a competent performance, with a significant improvement over the V1. Bass performance was tighter and more impactful, while midrange was much clearer - the V1 had a tendency to sound muffled and nasal. High frequencies also had a touch more openness and extension. Soundstaging on the V3 was also wider and more spacious, with better placement of voices and instruments. 

Tonally, I would say that the V3 had a slightly warm balance, with neutral bass and highs, and a laidback midrange. Some listeners may find the bass balance a bit light, but this can be fixed in the EQ settings.

Putting aside the richer feature set, the V3's sonic performance is reason enough to upgrade from the V1. 

The active noise reduction works reasonably well. However, as the name suggests it attenuates outside noise instead of canceling it. Nevertheless, the end result is good enough for the typical home environment, or for traveling. 

The microphone pickup is above average and voice pick-up is reasonably clear.  

Conclusion

The V3 is a solid performer at a bargain price. The Singapore online shop regularly runs promotions, and you can usually get a pair at a good discount - Best Buy

Creative Outlier Air V3

Driver

6 mm Bio-cellulose Driver

Battery Type and Life

Battery in Charging Case: 1 x Rechargeable Lithium Polymer Battery 450 mAh, Battery in Earbuds: 2 x Rechargeable Lithium-ion Polymer Battery 55 mAh

Charging Time

2 to 3 hours

Connector Type

Bluetooth 5.2

Audio Codec

AAC, SBC

Weather-proof Resistant

IPX5

Price - S$ 99

WFH Special #1 - Creative SXFI Gamer USB-C Gaming Headset

Introduction

The SXFI Gamer is a wired USB-C gaming headset with Super X-Fi technology and a flexible goose neck microphone (Creative Technology refers to this as "CommanderMic"). 

I am not suggesting that you play computer games during office hours while on your work-from-home stints. Instead, use your SXFI Gamer for conference calls, listening to music, and gaming sessions. You won't get the evil eye from your spouse too when justifying your purchase.

The recommended retail price is very reasonably priced at S$ 179.

Description

Super X-Fi  is Creative's proprietary technology that seeks to create a life-like soundstage that is akin to the music experience of listening to speakers. Regular headphone users will know that the soundstage is trapped in your head, which greatly diminishes the realism of the listening experience. 

To use Super X-Fi, you need to download the SXFI App on your phone, create an account and start the process of head and ear mapping. This involves using your phone camera to take pictures of your face and ears. 

The personalised settings are then downloaded into a SXFI certified headphone, like the SXFI Gamer.

The package includes the headphone set, the detachable CommanderMic, and both a USB C and 3.5 mm audio cable. A USB-C to USB adapter is thoughtfully provided in case your computer only has normal USB ports.

The 3.5mm audio cable looks like any stock cable, while the USB C cable is Kevlar jacketed which should provide long and reliable use. The USB cable is unfortunately very sensitive to microphonics and friction between the cable and your clothes will be picked up and annoyingly amplified.  

The headset comes with large and heavily padded over-ear pads which are mounted in a plastic frame that allows a small amount of swivel. Combined with the low-pressure headband, the SXFI Gamer is very comfortable to wear for extended periods of time. Noise isolation is also decent, with both little noise making it through, or being leaked out. The headband also has a numbered scale to make adjustments both easy and repeatable - something I wished that other manufacturers would do. Both headphone cups are equipped with an RGB ring. This is tastefully done, and you end up looking like a serious gamer rather than out-of-control Christmas tree lights.

Downloading the SXFI Control program on either your PC or Mac will allow you to adjust the EQ on your headphone, as well as customise the RGB rings on your headphone. You can also adjust between 2 channel mode and 5.1 or 7.1 modes, and other settings like the microphone and headset volume.

A variety of controls are placed on the left side of the headphone - a mic mute button, a volume control wheel, and buttons to toggle Super X-Fi and the RGB light mode (on, off, or a cycle mode).

The CommanderMic is equipped with active noise cancellation to suppress ambient noise. A red LED is placed at the microphone inlet so positioning is easy. The LED flashes when the microphone is muted, which is a nice touch.

I used the SXFI Gamer via USB on both a Windows 10 and macOS Catalina computer without any issues. I also did some testing via the 3.5mm jack on a variety of mobile phones and DAPs. 

Sound Quality  

Tonally, these headphones are close to neutral with good levels of detail. The 50mm drivers impart a solid and hefty feel to bass lines. However, the SXFI Gamer avoids the thick and heavy handed approach, so you will not get overblown or exaggerated bass. Bass is tight and tuneful, and powerful when the source material dictates it. If you like a bass-heavy presentation, you can always fix that through the EQ function.

Vocals are reproduced clearly and with minimal amount of grain. High frequencies have sparkle and extension, and cymbals have a crisp and clear response. There is a hint of splash and confusion during heavy mixes, but this is to be expected given the modest price of the SXFI Gamer. Sonics wise, these headphones perform way above the competition in the same price bracket.

Depressing the SXFI button toggles between the normal, Super X-Fi and Battle Mode. I found the Super X-Fi mode to work best on 5.1 and 7.1 material. At its best, this imparted a spacious and more speaker-like experience. However on 2 channel material, the effect is somewhat unnatural and hollow. Similarly, Battle Mode did its job on first-person shooters by altering the frequency curve to accentuate footsteps and suppressing the rest of the audio-band. While you can hear your enemies better, this came at the expense of an unnatural tone that made the experience less immersive and realistic. 

The surprise star of the show is the CommanderMic. The microphone is very clear and the software does a decent job of suppressing ambient noise. However, the microphone is highly directional and has to be pointed directly at your mouth for best results. I often preferred using these headphones for conference calls over my professional headsets from big-name manufacturers. 

The SXFI Gamer sounds almost identical using the 3.5mm cable, with results varying only slightly depending on the equipment used. These headphones are easy to drive and sound comfortable powered through a mobile phone jack. However, you will lose a lot of functionality as none of the buttons nor sound modes will work. Nevertheless this is a good option so that you can take the SXFI Gamer on a business trip and use them on the road or airplane with your mobile phone or DAP.

Conclusion

Equally comfortable doing multiple duties as a gaming or office headset, or music listening for the audiophile on a budget, the SXFI Gamer offers outstanding value at its recommended retail price of S$ 179. 

At the time of writing, they are being offered at a discounted price of S$89 which makes this an absolute no brainer - Best Buy. 

Creative SXFI Gamer USB-C Gaming Headset

Specifications

Audio Processing

Super X-Fi

Interface

USB, 3.5 mm Stereo Input

Weight

With Mic 349g (12.31 oz), Without Mic 336g (11.85 oz)

Frequency Response

20–20,000 Hz

Microphone

Frequency Response: 100–16,000 Hz
Sensitivity: - 42 dBV / Pa

Price : S$ 179

http://sg.creative.com/

Astell&Kern USB-C Dual DAC Cable

Introduction

Chances are that you use your notebook, tablet, or mobile phone to play music, especially through a streaming service like Tidal or Spotify. Sound quality is typically poor or mediocre. Integrated audio chips work in noisy electrical environments, and usually lack the necessary power to drive high-quality headphones. 

Astell&Kern have released a USB-C DAC / headphone amp that provides an instant boost to your sound quality and lets you use your 3.5mm wired equipment with devices that lack a headphone jack, like some of the new mobile phones.

Description

The USB-C Dual DAC Cable ("Dual DAC") is based on twin Cirrus Logic CS43198 MasterHIFI Digital-to-Analog Converters. The CS43198 is a Delta-Sigma oversampling DAC that supports up to 384 kHz sampling rate / 32-bit resolution for PCM and DSD 256. 

As expected from an Astell&Kern product, the Dual DAC is finished to a high standard. The compact metal Zinc alloy body (it is no bigger than a thumb-drive at 50 mm x 17 mm x 10.3mm !) houses an integrated circuit with bespoke designed capacitors and an optimised audio circuit to minimise power fluctuations and provide premium sound quality. 

Astell&Kern claims that the analog amplifier is powerful enough to drive a variety of high impedance headphones with a 2V rms output level (condition no load). Output impedance is suitably low at 2 ohms, which should ensure lower distortion into low impedance headphones. 

The fixed cable is a durable 4-core cable made out of a core of Technora aramid fiber, with a layer of thick silver-plated copper wrapped around it, followed by a further layer of copper wire in a spiral arrangement. The tastefully angled housing is carried over to the matching USB-C connector. A single LED indicates operation, while volume is controlled through the device it is paired with. 

Operation

The Dual DAC worked without any issue with a variety of devices I tried - a Samsung Galaxy S10+ mobile phone, a Windows 10 notebook, and a 2020 Macbook Pro notebook. The bulk of my listening was done on the Samsung, playing music either through the Tidal or USB Audio Player Pro app. Power-draw was modest and I did not notice any adverse impact on battery life. Sadly, the Dual DAC is incompatible with iOS devices due to current limitations through their ports. Both high-resolution PCM and DSD files played without any issue.

The USB-C connector is quite large and may not fit properly through your mobile phone case. My case cut-outs were not big enough and I had to remove my phone case to plug in the Dual DAC. I am in two minds about the fixed lead. I like the idea of a fixed cable, but it is quite short and in the case of my Windows 10 notebook, the USB ports are located on the side of the screen, which left the Dual DAC suspended in the air.

Sound Quality

The Dual DAC provided a significant uplift in sound quality and drive capability, with the improvements most noticeable on difficult to drive headphones. I tried it with a variety of IEMs, as well as two headphones - a Beyer DT880 (250 ohm version) and an E-MU Teak. Most of my listening was done on the E-MU for reasons explained below.

The most striking improvement was in the reproduction of low-frequencies. The Dual DAC added a tight punchiness that went deep. Vocals gained clarity and refinement, adding sweetness and uncovering details that were previously obscured. High-frequencies too gained extension and airiness, giving music a brighter and more illuminated tone. The soundstage opened up, with an increase in dimensionality, and the sense of acoustic space in the recording.

Pairing the Dual DAC with IEMs brought improvements in sound quality, but the Dual DAC's strength was in bringing extra current and voltage drive for more difficult to drive headphones (within reason). While the DT880 showed improvements with the Dual DAC, it lacked the dynamic freedom and ease compared to my desktop headphone amps. The E-MU Teak is easier to drive in comparison and was very comfortable with the Dual DAC, even at high levels. Given the compact size of the Dual DAC, this is a reasonable compromise.

I was impressed with the high level of sound quality delivered by the Dual DAC and can highly recommend it to Android phone users who want the best sound quality on the go, or to business travelers that need a high-quality and portable audio rig.

Conclusion 

From a pricing standpoint, the Dual DAC is a premium product that carries a corresponding price tag. The competition offers similar products, some at a lower price point with features like balanced drive capability. I think the pricing is fair, and like any Astell&Kern product, you get lasting pride of ownership. 

The Dual DAC will be available in May 2021 at a retail price of S$ 189- Highly Recommended.

You can purchase the Dual DAC from AV One (https://av1group.com.sg), Connect IT, E1 Personal Audio, Headphones.SG, Jaben, Stereo Electronics, and Treoo.com.

 

 

  

Bottlehead Crack and Bottlehead S.E.X. Headphone Amplifiers

Introduction

COVID-19 and the lockdown making you sing the blues? Maybe it's time to get out your soldering iron, and start building a kit that you had your eyes on? That's exactly what I did - my poor Bottlehead S.E.X. kit has been collecting dust since I ordered it sometime last year. 

Bottlehead is an established company that has been offering vacuum tube kits to audiophiles since 1995. Their product range covers a wide variety of tube equipment, as well as a speaker kit. 

While kits are not for everyone, I encourage every audiophile to at least try assembling a kit at least once. A lot can be learnt from the experience, including soldering, basic circuit design, patience, and the ability to use swear words in ways that you never thought possible. 

On a more serious note, immense satisfaction can be obtained from building something that you can truly call your own masterpiece. Photos of builds around the world show that audiophiles are a pretty talented lot, with some builds exhibiting build techniques and wood / metalworking quality that can put even professional companies to shame.

As an educational process, I probably learnt more from DIY work than anything else. Mistakes in assembly or poor construction technique will teach you many things, including the importance of good grounding practice, and the importance of proper wire routing.

Bottlehead kits are far from being the cheapest on the market, but their builds are guided by very clear instructions with lots of pictures. They also have a very supportive online forum where you can find a lot of tips and suggestions for modifications. If you encounter problems, the folks there are helpful and willing to go the extra mile to ensure your build is successful.

Introduction to Crack 

This type of Crack is legal around the world and no need to risk your liberty or health to enjoy this. 

The Bottlehead Crack 1.1. OTL Headphone Amplifier kit is described as a Level 1 kit, perfect for first time builders, involving an evening or two of build time. The cheeky name is a common trait across Bottlehead products - they believe that their products involve feelings of euphoria!

The circuit of the Crack is simple, with a low parts count. The power supply is a C-R-C-R-C design, so no chokes to complicate your life (and more importantly, bump up the cost of a starter kit). A lone 12AU7 tube is directly coupled to a similarly lonely 6080 tube used as a cathode follower. As both tubes are dual triodes, each triode section handles one channel. 

There is no output transformer (OTL means Output Transformer Less). Tube designs typically need an output transformer to match the high resistance of the tube output stage, to the low impedance load being driven, e.g. a loudspeaker or headphone. The choice of the 6080 tube (which has a relatively low plate resistance), allows the omission of an output transformer provided that the matching headphone has a high impedance. The Crack has an output impedance of 150 ohms, and is recommended to be paired with headphones of 200 ohms or higher. Parts quality is decent with nothing fancy save for the ultrafast rectifiers. The two most obvious cost-saving measures are the electrolytic output coupling capacitors and the cheap carbon potentiometer.

The Crack can also be upgraded with the Speedball upgrade kit, which is a constant current source supply for the plate of the 12AU7 tube, and the cathode load of the 6080 tube. A similar upgrade kit is also available for the S.E.X.   

Introduction to S.E.X.

This is a family-friendly blog, and this is one three-letter word that can be legally enjoyed with the whole family. Like Crack, S.E.X. is a two-stage circuit. Version 3.0 of the S.E.X. uses a 6FJ7 tube. If you have never heard of the 6FJ7, that makes two of us. The 6FJ7 is a dual triode with dissimilar sections fitted in a Compactron envelope. Described as a TV oscillator tube, this is not a tube that you will be fighting over with other audiophiles.     

The S.E.X. is a substantially more complicated build compared to the Crack. I took more than four evenings to complete the kit, taking my time to carefully check the instructions, and building the kit at a leisurely pace. The S.E.X. has five transformers, consisting of one power transformer, two output transformers, and two plate chokes. Unlike the Crack, the S.E.X. is able to power sensitive speakers, with 2W on tap. 

After completing the kit, I admired my extremely skillful soldering, powered up everything, and music flowed forth like voices from Heaven. The truth of the matter is that I could not pass the resistance tests as set out in the instruction manual and had to go to the Bottlehead Forum for help. Bottlehead's Paul Birkeland noticed almost immediately that one of my ground wires was not connected and all resistance tests passed after I fixed that. Interestingly, I had no plate voltage on one channel. Checking all connections carefully with a magnifier and torchlight showed that one of my connections had not yet been soldered. Some of my sloppier solder joints were re-flowed and everything was good after that, or so I thought.

I switched on the S.E.X. only to be greeted by loud popping and static from one channel. This was puzzling since I was pretty sure that all issues had by now been addressed. After swapping interconnects, I realised that the sound would stop when I gently tapped the chassis near the left tube. I removed the left tube and after a few sharp taps to the envelope (please do not do this to a hot tube), it was quiet - time to look for a replacement tube.      

Build Experience

I bought the Crack pre-owned, and it came with the Speedball upgrade already installed. So, my experience relates to my build of the S.E.X. kit.

Thanks to the excellent instructions and well-thought-out kit, assembly of either kit should be achievable, even for the novice who cannot read a circuit diagram. However, understanding the circuit makes things a lot easier, as well as good soldering techniques. Neither of these kits is in my opinion suitable for a person with no soldering experience, nor a basic understanding of electronics. My suggestion is for the inexperienced to do some basic reading, and practice stripping wires, trimming parts and soldering some waste or spare components on a practice board.

The instructions are also catered for the world of Imperial measurements. I had absolutely no idea what a number #4, #6 or #8 screw size is, although to give Bottlehead credit, some of these parts are listed in the instructions with metric dimensions.

It also pays to be very attentive when reading the instructions. As multiple connections may be made to a single terminal hole, you have to make sure that you only solder the point when asked to do so. Despite taking my time, I made this mistake a few times. Thankfully the terminal strips have plenty of space for fixing these mistakes.

Due to a mistake made in stripping the supplied ethernet cable (used for signal hook-up), I had to use some spare Canare star-quad microphone cable to run from the RCA sockets to the potentiometer. Otherwise, I used all the parts as supplied. The carbon potentiometers could have better tracking, and show noticeable channel mismatch at very low volume levels. At practical listening volumes, the channel tracking was acceptable.  

Sound Quality

In today's episode of Spy vs. Spy, will White Spy (S.E.X.) or Black Spy (Crack) emerge triumphant? 

To give both spies a level playing field, only two high impedance headphones were used - a Sennheiser HD6xx (300 ohms) and a Beyer DT-880 (250 ohms). Both spies were sent on physical training camps and a few simple missions to ensure that they were in tip-top condition. 

Black Spy by virtue of its creamy and wet midbass will win over a lot of fans. I thought it would make the Sennheiser sound too dark, but it actually worked quite well. For the brighter sounding Beyer, it added fullness and heft to the sound. Black Spy was not the most meticulous or detailed of spies and glossed over some details. However, if you have an aversion to thin, bright and etched recordings, Black Spy will be your best friend.

The Crack is not tonally neutral. It adds a pleasing warmth to your recordings and takes an edge off all the nasties. Bass control is a bit loose and if you favour fast-paced rock or EDM tracks, this is probably not the best choice for you. 

White Spy, on the other hand, is leaner, faster, and a lot more detailed. The immediate thought that strikes you is, "Where did the bass go?". The bass is taut, tuneful, and very controlled with no flab. I actually appreciated the detailed and articulate bass lines of the S.E.X. 

In similar fashion, vocals are more open and textured, with a deeper insight into the recording. The neutral approach also means that your enjoyment will be dependent on the quality of your recording. My only criticism of the S.E.X. is that I did find myself missing the bass impact of the Crack. A half-way house between the two would have been perfect. I will revisit how the S.E.X. performs after installation of the CCS upgrade kit. 

Conclusion

Which kit is best for you ? My thoughts on this :-

Crack 

• First-time builder
• Preference for a warm and forgiving sound
• To be paired suitable headphones (>200 ohm impedance)

S.E.X.

• Second-time or advanced builder
• Preference for a faster and more neutral sound
• To be paired with a variety of headphones, including low impedance models
• To be paired with sensitive speakers 

A select few listeners would prefer the Crack over the S.E.X. I personally think the S.E.X. is worth the extra cost for a more sophisticated sound, better transparency, and more flexibility with partnering equipment. 

Bottlehead Crack
USD 315 or 430 with Speedball Upgrade

Bottlehead S.E.X.
USD 539 or 574 with C4S Upgrade

Products are sold directly from bottlehead.com

News - Mr Speakers, renamed Dan Clark Audio released the Aeon 2 portable headphones in Singapore

SINGAPORE | December 20th, 2019 

Dan Clark Audio is pleased to announce the launch of the all new Aeon 2 Open and Closed high-fidelity over-ear headphones in Singapore. The new headphones build upon the legacy of its predecessor - the ever popular AEON Flow headphones, but ramped up with new design elements. Previously known as Mr Speakers, the company rebranded to Dan Clark Audio, the founder's namesake.

Dan Clark, founder of Mr Speakers, and now Dan Clark Audio, is an electrical engineer who has been working in and around the high-end audio market for more than twenty years. Dan’s experience includes working in high-end retail, designing amplifiers and electronics for personal use, and designing commercial and custom loudspeaker solutions, including the highly-regarded and award winning Platinum Audio speakers from the late 1990’s.

The new Aeon 2 features the latest engineering innovations from Dan, married with smart industrial design at a price that makes them not only attainable, but thoroughly enjoyable for the Hi-Fi community.

The original Aeon broke new grounds with its smart industrial design that is the hallmark of Dan Clark Audio design ethic. Known for its elegant shape of the ear-cups, lightweight nitinol headband, and the amazing performance of its in-house designed planer drivers, it was highly raved when it first launched. Now, with Aeon 2, it encompasses all the goodness of the original Aeon with the following new advancements:

Improved Performance

The new Aeon 2 features a colossal performance upgrade. Dan and his team took what they learned designing the most awarded planar headphones in the market last year - the Ether 2, and completely redesigned the driver from the ground up for the new Aeon 2.

New features include:
Updated driver structure flipped 180 degrees, removing magnet and flow structures from the direct signal path of the ear
Streamlined flow elements converted to a single construction, removing gaps
Higher precision machined flow structures vs. injection moulding
Superior Driver damping by developing new materials resulting in improved resolution and frequency response

The sum of all these innovations is a headphone that resolves music on an emotional level unheard of at this price point: visceral bass, transparent mids, and detail up top that is complementary not fatiguing.

Uncompromised Portability

The engineering team at Dan Clark Audio noticed that while the original Aeon came with a great case, it was a little bulky and hard to travel with. When they set out to create the next iteration of Aeon, the team knew they had to address Aeon 2's portability without sacrificing performance.

The attention to small details for their customers in mind resulted in a new case for Aeon 2, and an intelligent folding mechanism for the headphones, as part of its smart industrial design ethos. The new and improved Aeon 2 that would travel more efficiently without sacrificing function and performance.

The headphones are not only more compact and easier to bring along for your travels now, the new design actually improved the clamping, fit, feel, and structural integrity of the entire headphones. The form fitting and protective case also fits your cable of choice and takes up half the room in your backpack than the old Aeon case.

Pricing and Availability

Dan Clark Audio Aeon 2 is available immediately at a recommended retail price (RRP) of S$1,399 (including GST) exclusively at AV One and Lazada (https://www.lazada.sg/shop/av1group).

About Dan Clark Audio

Dan Clark Audio was founded with a simple goal in mind: make great headphone products and have fun doing it. At Dan Clark Audio, we believe audiophile performance can be delivered at a variety of prices and we strive to deliver incredible performance and high value for each and every product. Founded by Dan Clark, an electrical engineer who has been working in and around the high-end audio market for more than twenty years. Dan’s experience includes working in high-end retail, designing amplifiers and electronics for personal use, and designing commercial and custom loudspeaker solutions, including the highly-regarded and award winning Platinum Audio speakers from the late 1990’s. Dan has a particular fondness for Isobaric subwoofers.

News : Meze Audio launches multi-award winning headphones - Empyrean, the first Isodynamic Hybrid Array Headphone in Singapore

SINGAPORE | 16th August 2019 - Meze Audio, a high-end audio company renowned for developing premium audiophile headphones and earphones, introduces their new flagship: Empyrean - the first Isodynamic Hybrid Array Headphone with Eng Siang International as its sole official distributor in Singapore. 

The stunning pair is made in collaboration with Rinaro, a progressive audio company with over 30 years of research and development on planar magnetics. It has bagged 13 awards and counting since its initial launch.

Antonio Meze, lead designer and founder of Meze Audio said "Empyrean was born from passion, curiosity and innovation. As a business, we have allowed ourselves the freedom to experiment and take risks in search of the perfect sound. To generate something truly remarkable, one must dare to explore, and that's what we did with Empyrean. We pushed and refined industry's standards and achieved a true game changer for audiophiles."

Headphones with no compromise

The result of the collaboration brings a no-compromise ultra high resolution audio headphones with an Isodynamic Hybrid Array Driver, MZ3, made exclusively for the Empyrean.

With MZ3, an Isodynamic Hybrid Array Driver, a new standard in planar magnetic audio was established - the first dual shaped voice coil array. The only one of its kind, this unique piece of technology is one of the lightest and most advanced planar magnetic drivers on the market.

The MZ3 combines individual switchback and spiral shaped voice coils, allowing sound to be targeted with accuracy around the natural shape of the ear, ensuring absolute comfort and fit for the listeners. This also provides increased exposure of direct sound wave frequencies over the 10kHz range and improves imaging and location by decreasing the impact of short wave time delays caused by diffused field reflections.

Designed with users in mind

Embodying Meze's daring aesthetic, user-centred design elements and Rinaro's experience in research and development within the field of planar magnetics, Meze Empyrean is both a sophisticated piece of design, and one of the most technologically innovative planar magnetic headphones. 

An innovative feature is the Isomagnetic ear cup attachment which utilises the demagnetising field generated by the driver to hold the ear cup in place whilst also redirecting the magnetic field back into the driver and improving driver efficiency. Empyrean's cleverly designed pressure distribution wings - a patented suspension wings increase the leather headrest's contact surface area with your head and can help relieve uncomfortable pressure points.

Empyrean comes with 2 sets of detachable ear pads, in leather and Alcantara variants. Not just luxurious, each pad variant presents a different soundscape for the user. With the leather pads, one can enjoy the vocal and instrumental nuances of your favourite playlist, focusing more on the mids. The Alcantara pads gives you more depth and attention to the treble details. 

Exquisite craftsmanship

Meze went out of their way to create an audiophile headphone that is powerful yet lightweight enough for extended hours of use. A blend of premium materials, the Empyrean utilises exquisite craftsmanship and detailing that unmistakably Meze.

Each driver has been hand assembled and tested in an industrial facility in Ukraine. 

Designed and engineered in Baia Mare, Romania, the Empyrean is made of lightweight carbon and aluminium using high precision Computer Numeric Control (CNC) sculpted chassis, milled from a single piece of solid aluminium. Each cut is precise and a work of art in its own right.

• Driver Type: Rinaro Isodynamic Hybrid Array 

• Frequency Response: 4 - 110,000 Hz

• Impedance: 31,6 Ω

• Weight: Approximately 430g

• Accessories included: High strength aluminium suitcase with foam inserts case, 2 sets of ear pads: Real leather, Alcantara, Cable options: 3m OFC cable, 4pin mini XLR plugs ending with 6.3 jack connector OR 1.3m OFC cable, 4pin mini XLR plugs ending with 3.5 jack connector or 3m OFC cable, 4pin mini XLR plugs ending with 4 pin XLR connector

Specifications

Price and Availability

Meze Empyrean is available immediately at the recommended retail price (RRP) of S$4,599 (including GST) at authorised retailers including AV One, E1 Personal Audio, and Lazada (https://www.lazada.sg/shop/av1group).

About Meze Audio

Meze Audio was founded in 2011 in Baia Mare, Romania. Meze Audio headphones embody the classical values of clarity, balance and harmony. This is not a trend and it's not intended to last for just a season. These are Classics. These are devices to fall in love with. We achieve this standard by combining high-end technology and style with quality materials and good craftsmanship. To all this we add the most important ingredient: our passion.

All our models, headphones and earphones, are developed in-house from the ground up, in the spirit of our original 'no-compromise' vision.