With much happiness I post this review of the Aclear Porta NXT-2AK Headphone Conditioner by Nakamura Corp. (4 1/2 years in the making). Unfortunately, and with much regret this review comes at a time when Nakamura Corp. simply are not offering this product anymore. It would go on to be replaced by an inferior and cheaper product and the line of portable headphone conditioners offered, ultimately scrapped by the company all together to focus on their desktop/home solutions.
Fortunately for myself I happened to stumble upon Nakamura Corp. purely by chance when yours truly was just stepping back into the personally audio hobby. At the time it had been many years since owning a simple home setup consisting of an old school pioneer receiver and decent sony speakers. Before that my personal audio portable was the venerable Iriver H40, which as young as I was at the time was truly eye opening.
Rewind 4 1/2 years ago and I was taking a good look into and ultimately investing in the Sony PCM D100 personal audio recorder and stepping back into personal audio. Based on what I had read it would do nicely for my foray back into audio, though it wouldn't necessarily provide the cleanest and blackest background out there due in large part to it pulling double duty and built mostly with the intention of recording. Knowing I was not deterred and purchased it post haste. Being happy with this setup and at the time using the Sony DR-Z7 going on at the time 30 years old, I was quite pleased with the clean and extremely detailed sound. However, it would be after stumbling upon a post by user @windwolf447 here in regards to a headphone conditioner few had heard of and his youtube video, that I was intrigued further if this could round out my setup and provide a little more audio pleasure.
Reaching out personally to the company and after a series of exchanges they graciously provided a unit with the intention of a review. However, things were not conducive for me to hold to that agreement and though I reached out and made it clear I would be put on hold indefinitely for the review, they were kind enough to let me keep the unit until I could produce. After much hard times, and eventually working my way out of those hard times, I was able to focus more on audio and even put out a review for my latest player at the time, the Aune M2S, which too this day still holds a special place in my heart. The Aune M2S was able to give me that quality playback that reminded me of my setup with the PCM-D100 and Sony DR-Z7 combo I no longer owned.
At first there was simply no using the conditioner with the Aune, as the M2S only had a SE and LO and the included cable that came with the NXT-2AK was built with the intention of the AK series of players with their 2.5mm TRRS balanced out. I would remedy this though and purchase a SE to SE cable and was surprised at what this conditioner could do even though I was told beforehand in the booklet :
![20180218_134224[1].jpg](https://cdn.head-fi.org/a/10072069_thumb.jpg "20180218_134224[1].jpg")
From seeing here on the top of the last page it reads, "5. It can ensure enough volume levels in most DAP's even with high impedance headphones.". This would be big for me as I made my move from the still worthwhile and very affordable Sony MH1C to the latest MEE P1's (with its 150 Ohm impedance). Additionally, it should be mentioned right here this also has a VERY nifty ability to Impedance match headphones to the source from a range of 12-300 OHMs. Going forward, this would allow me the comfort of knowing that no matter the player, things like impedance matching were not going to be a concern as far as my personal setup was concerned. My issue with the Aune at the time was they simply couldn't give as great of a quality playback without their B1 amp to pick up and carry the driving duties, as well as from plugging my MEE P1's straight into the player. The bass was lacking and the mids seemed recessed based off memory, with the highs being nothing special. With the B1 only, it was better but at the same time that stack was not very fun to lug around and quickly my biggest gripe would end up being 4hrs of playback with the B1 attached, in addition to the weight. After forgetting about the NXT-2AK for a minute I decided to test the Aune M2S and headphone conditioner to see what if anything would happen. To my immediate surprise I realized the overall sound signature was much more balanced then what it had been by the player itself. Even more surprising with the MEE P1 I felt the bass was full of quality and quantity, something I had needed to rely on the B1 amp to provide. Suddenly I was coming to the realization I didn't need the b1 amp anymore, and was quite happy for sometime with this pairing. This would be the first time that I could really hear and understand what the Nakamura was providing me. It was taking all the good and simply making it better within reach to acquire. No longer was I tethered down and consistently monitoring a battery waiting for it to cut off. No longer was that sneaking suspicion there that this was somehow not as good as I felt it could be. The Aclear Porta NXT-2AK had finally delivered on its promises and finally I had grown actual appreciation for this personal audio accessory.
Fast forward a bit and I would come to sell off the Aune in favor for a new product I had accidentally come across, the Venturecraft Soundroid Valoq 627SM Limited Edition. While being a capable player in its own right and certainly having a few issues of its own, I would again see the benefit of using the headphone conditioner albeit in smaller doses this time. See, the Valoq had a lot going for it right off the back with the latest AKM VERITA AK4490 DAC chip (at the time) and 627sm op amp, which is quite respectable in circles for those in the know. It honestly didn't benefit from the headphone conditioner much, albeit though a slightly blacker background with little extension on both sides of the spectrum, though not very noticeable. It would be around this time that I would participate with a series of headphone tours provided and setup by user @Barra. Additionally, I would just so happen to lose my phone and have it replaced with the LG V10. For the sake of providing well rounded user feedback I would eventually end up utilizing the V10 with all the phones that came my way (Lime Ears Aether, AAW 900 &500, Hidition Nt6 & Nt6PRO, 64 Audio Tia Fourte & Tzar18) in addition to my P1's. This would be the second time my eyes would be open to the awesome sauce inside the headphone conditioner. Due in large part to the fact that most players I used in the past were made from the ground up to concentrate purely on sound, there was very very little background noise/hums and clicks I ever discerned. However, with the sensitivity of some of these phones and the amp in the LG V10 I was able to pick those noises out right away. Using the screen, opening an app, turning off and on the wifi were things I could hear noticeably. When pairing the Headphone Conditioner with the phone and IEM's this was greatly reduced and limited those noise artifacts, which resulted in a much better listening experience all around, though it did little to bring me around to the overall signature of the LG V10 itself.
Since taking part in those tours time has moved on, and I've found myself the owner of Hifiman's now older TOTL player, the 901s. For those that have interacted and conversed with me will know I make no effort to hide my love for this player, which currently utilizes the Minibox Gold. Using the two together now with and replacing the included IC with a much better (IMHO) IC from Double Helix Cables, Comp4. I feel this has brought the Hifiman, further extension, tighter and more controlled bass, a touch of clarity in the mids, while bringing a shine to the mid treble - high treble region without bringing any sign of harshness. Depth of the soundstage I feel deepened if only enough to give the impression of a blacker background which has been my experience in the past with certain players. The higher end of the frequency spectrum is allowed to reveal itself in such a way while not getting to a point of exacerbation, the nuance and micro details, splash of a high hat are true to life. Its been very interesting with this current setup fueled by my recent purchase of the Sony XBA Z5, a IEM by all means considered fun, smooth and warm by most. With the Alo Audio Reference 8 cable now in the frame along with my player and conditioner I have a sound I'm very happy with, wide extension on both side with GREAT control. The mids never get buried, are more in line and are just as revealing as the rest of the frequency. The Synergy is simply outstanding while providing a very balanced signature (every way an upgrade to my favorite P1s and coming very close to and exceeding other top tier offerings provided by companies in the past), and having tested much higher priced gear I feel this keeps up in every way while saving me mucho dinero.
One final thing I will leave here in regards to the NXT-2AK is something again unique to this particular model. It has output for 2.5mm trrs and 3.5mm trrs and 3.5mm trs. Meaning I really don't have to worry about purchasing cables and getting them re-terminated since I can just swap out the IC between source and the conditioner. This has been a convenience that has further saved me money, and allowed me to do what I love which is just focus on the music. It's really a shame Nakamura Corp. does not make this anymore as I feel the market it was aimed at was simply slow to catch on to what they were doing. Simply put they were ahead of the curve in meeting the needs of the customer base. With evermore conveniences such as WIFI, bluetooth, Android OS as well as DAC functionality being requested and implemented in todays DAP scene this would help to give consumers that little bit to pull from their systems for those willing to spend the money, to get there all while stripping the noise that comes with those conveniences asked.
Which brings me to my only negative about the NXT-2AK, its price tag. At retail it was I believe around 400 or so dollars. That's quite an investment to ask for when there really isn't a lot known about your product. At the same time with balanced HO 2.5mm trrs, 3.5mm trrs, and SE3.5mm trs, carbon fiber surface panel and their unrivaled even to this day "super thin, high -performance isolation transformer in a machined aluminum case". You can easily see they were putting out a product with their aim on QUALITY first and foremost and everything else second..
Thank you Nakamura Corp. for this wonderful piece of kit, thank you for your trust, and may this serve as a testament to a product never regarded for what it should have been. I eagerly await the day you decide to cater to the portable market again as I'll be waiting with open arms and open HO.
4 1/2 years in the making....better late than never.
Specifications:
Max Specification Level : 250 mw/ch
Matched Impedence: 12-300 OHMS
Frequency Property: 5Hz - 70kHz
Input terminal: 3.5mm trrs 4- pin stereo mini jack
Output terminal 3.5mm trrs 4pin stereo mini jack,
2.5mm trrs 4 pin stereo jack (compatible with 3.5mm trs)
Size: Width ca.55 mm, Depth ca.88 mm, Heigh ca. 14.5mm, Weight ca.160 g
Accessories: 1 x 3.5mm trrs 4-pin - 2.5mm trrs 4 pin gold plated plug 18 cm long.
Edited, rounded out impressions, and changed the beginning which I felt was a little redundant.
Fortunately for myself I happened to stumble upon Nakamura Corp. purely by chance when yours truly was just stepping back into the personally audio hobby. At the time it had been many years since owning a simple home setup consisting of an old school pioneer receiver and decent sony speakers. Before that my personal audio portable was the venerable Iriver H40, which as young as I was at the time was truly eye opening.
Rewind 4 1/2 years ago and I was taking a good look into and ultimately investing in the Sony PCM D100 personal audio recorder and stepping back into personal audio. Based on what I had read it would do nicely for my foray back into audio, though it wouldn't necessarily provide the cleanest and blackest background out there due in large part to it pulling double duty and built mostly with the intention of recording. Knowing I was not deterred and purchased it post haste. Being happy with this setup and at the time using the Sony DR-Z7 going on at the time 30 years old, I was quite pleased with the clean and extremely detailed sound. However, it would be after stumbling upon a post by user @windwolf447 here in regards to a headphone conditioner few had heard of and his youtube video, that I was intrigued further if this could round out my setup and provide a little more audio pleasure.
Reaching out personally to the company and after a series of exchanges they graciously provided a unit with the intention of a review. However, things were not conducive for me to hold to that agreement and though I reached out and made it clear I would be put on hold indefinitely for the review, they were kind enough to let me keep the unit until I could produce. After much hard times, and eventually working my way out of those hard times, I was able to focus more on audio and even put out a review for my latest player at the time, the Aune M2S, which too this day still holds a special place in my heart. The Aune M2S was able to give me that quality playback that reminded me of my setup with the PCM-D100 and Sony DR-Z7 combo I no longer owned.
At first there was simply no using the conditioner with the Aune, as the M2S only had a SE and LO and the included cable that came with the NXT-2AK was built with the intention of the AK series of players with their 2.5mm TRRS balanced out. I would remedy this though and purchase a SE to SE cable and was surprised at what this conditioner could do even though I was told beforehand in the booklet :
![20180218_134224[1].jpg](https://cdn.head-fi.org/a/10072069.jpg "20180218_134224[1].jpg")
From seeing here on the top of the last page it reads, "5. It can ensure enough volume levels in most DAP's even with high impedance headphones.". This would be big for me as I made my move from the still worthwhile and very affordable Sony MH1C to the latest MEE P1's (with its 150 Ohm impedance). Additionally, it should be mentioned right here this also has a VERY nifty ability to Impedance match headphones to the source from a range of 12-300 OHMs. Going forward, this would allow me the comfort of knowing that no matter the player, things like impedance matching were not going to be a concern as far as my personal setup was concerned. My issue with the Aune at the time was they simply couldn't give as great of a quality playback without their B1 amp to pick up and carry the driving duties, as well as from plugging my MEE P1's straight into the player. The bass was lacking and the mids seemed recessed based off memory, with the highs being nothing special. With the B1 only, it was better but at the same time that stack was not very fun to lug around and quickly my biggest gripe would end up being 4hrs of playback with the B1 attached, in addition to the weight. After forgetting about the NXT-2AK for a minute I decided to test the Aune M2S and headphone conditioner to see what if anything would happen. To my immediate surprise I realized the overall sound signature was much more balanced then what it had been by the player itself. Even more surprising with the MEE P1 I felt the bass was full of quality and quantity, something I had needed to rely on the B1 amp to provide. Suddenly I was coming to the realization I didn't need the b1 amp anymore, and was quite happy for sometime with this pairing. This would be the first time that I could really hear and understand what the Nakamura was providing me. It was taking all the good and simply making it better within reach to acquire. No longer was I tethered down and consistently monitoring a battery waiting for it to cut off. No longer was that sneaking suspicion there that this was somehow not as good as I felt it could be. The Aclear Porta NXT-2AK had finally delivered on its promises and finally I had grown actual appreciation for this personal audio accessory.
Fast forward a bit and I would come to sell off the Aune in favor for a new product I had accidentally come across, the Venturecraft Soundroid Valoq 627SM Limited Edition. While being a capable player in its own right and certainly having a few issues of its own, I would again see the benefit of using the headphone conditioner albeit in smaller doses this time. See, the Valoq had a lot going for it right off the back with the latest AKM VERITA AK4490 DAC chip (at the time) and 627sm op amp, which is quite respectable in circles for those in the know. It honestly didn't benefit from the headphone conditioner much, albeit though a slightly blacker background with little extension on both sides of the spectrum, though not very noticeable. It would be around this time that I would participate with a series of headphone tours provided and setup by user @Barra. Additionally, I would just so happen to lose my phone and have it replaced with the LG V10. For the sake of providing well rounded user feedback I would eventually end up utilizing the V10 with all the phones that came my way (Lime Ears Aether, AAW 900 &500, Hidition Nt6 & Nt6PRO, 64 Audio Tia Fourte & Tzar18) in addition to my P1's. This would be the second time my eyes would be open to the awesome sauce inside the headphone conditioner. Due in large part to the fact that most players I used in the past were made from the ground up to concentrate purely on sound, there was very very little background noise/hums and clicks I ever discerned. However, with the sensitivity of some of these phones and the amp in the LG V10 I was able to pick those noises out right away. Using the screen, opening an app, turning off and on the wifi were things I could hear noticeably. When pairing the Headphone Conditioner with the phone and IEM's this was greatly reduced and limited those noise artifacts, which resulted in a much better listening experience all around, though it did little to bring me around to the overall signature of the LG V10 itself.
Since taking part in those tours time has moved on, and I've found myself the owner of Hifiman's now older TOTL player, the 901s. For those that have interacted and conversed with me will know I make no effort to hide my love for this player, which currently utilizes the Minibox Gold. Using the two together now with and replacing the included IC with a much better (IMHO) IC from Double Helix Cables, Comp4. I feel this has brought the Hifiman, further extension, tighter and more controlled bass, a touch of clarity in the mids, while bringing a shine to the mid treble - high treble region without bringing any sign of harshness. Depth of the soundstage I feel deepened if only enough to give the impression of a blacker background which has been my experience in the past with certain players. The higher end of the frequency spectrum is allowed to reveal itself in such a way while not getting to a point of exacerbation, the nuance and micro details, splash of a high hat are true to life. Its been very interesting with this current setup fueled by my recent purchase of the Sony XBA Z5, a IEM by all means considered fun, smooth and warm by most. With the Alo Audio Reference 8 cable now in the frame along with my player and conditioner I have a sound I'm very happy with, wide extension on both side with GREAT control. The mids never get buried, are more in line and are just as revealing as the rest of the frequency. The Synergy is simply outstanding while providing a very balanced signature (every way an upgrade to my favorite P1s and coming very close to and exceeding other top tier offerings provided by companies in the past), and having tested much higher priced gear I feel this keeps up in every way while saving me mucho dinero.
One final thing I will leave here in regards to the NXT-2AK is something again unique to this particular model. It has output for 2.5mm trrs and 3.5mm trrs and 3.5mm trs. Meaning I really don't have to worry about purchasing cables and getting them re-terminated since I can just swap out the IC between source and the conditioner. This has been a convenience that has further saved me money, and allowed me to do what I love which is just focus on the music. It's really a shame Nakamura Corp. does not make this anymore as I feel the market it was aimed at was simply slow to catch on to what they were doing. Simply put they were ahead of the curve in meeting the needs of the customer base. With evermore conveniences such as WIFI, bluetooth, Android OS as well as DAC functionality being requested and implemented in todays DAP scene this would help to give consumers that little bit to pull from their systems for those willing to spend the money, to get there all while stripping the noise that comes with those conveniences asked.
Which brings me to my only negative about the NXT-2AK, its price tag. At retail it was I believe around 400 or so dollars. That's quite an investment to ask for when there really isn't a lot known about your product. At the same time with balanced HO 2.5mm trrs, 3.5mm trrs, and SE3.5mm trs, carbon fiber surface panel and their unrivaled even to this day "super thin, high -performance isolation transformer in a machined aluminum case". You can easily see they were putting out a product with their aim on QUALITY first and foremost and everything else second..
Thank you Nakamura Corp. for this wonderful piece of kit, thank you for your trust, and may this serve as a testament to a product never regarded for what it should have been. I eagerly await the day you decide to cater to the portable market again as I'll be waiting with open arms and open HO.
4 1/2 years in the making....better late than never.
Specifications:
Max Specification Level : 250 mw/ch
Matched Impedence: 12-300 OHMS
Frequency Property: 5Hz - 70kHz
Input terminal: 3.5mm trrs 4- pin stereo mini jack
Output terminal 3.5mm trrs 4pin stereo mini jack,
2.5mm trrs 4 pin stereo jack (compatible with 3.5mm trs)
Size: Width ca.55 mm, Depth ca.88 mm, Heigh ca. 14.5mm, Weight ca.160 g
Accessories: 1 x 3.5mm trrs 4-pin - 2.5mm trrs 4 pin gold plated plug 18 cm long.
Edited, rounded out impressions, and changed the beginning which I felt was a little redundant.
