genuine national JDSLABS Objective2 By NwAvGuy headphone amplifier JDS LABS

I am happy with the sound quality. Good soundstage and separation. Quiet backround.

i side by side compare the Beyerdynamic A20, Matrix M-stage, NuForce HA200, Asgard 2 with this amp, Beyerdynamic A20 is worth the price, you can hear the difference more bass and more detailed highs, I tested it with HD650 and shure 535 LTD, a close behind is Matrix M-stage, which connect directly through USB cable to Macbook, I run only FLAC loss-less file on VOX player on Mac, the NuForce HA200, Asgard 2 and quite far behind the matrix and this amp, but i do hear the difference between t his amp and Matrix M-stage, it's worth the extra price paid. Note I used Fiio E10K as DAC USB input from Macbook, and use 3.5mm to RCA output to connect the Beyerdynamic A20 amp, this amp is the last ranking to my test, it's too much blur bass.

be warned, this amp is not very powerful. a disappointment to be honest. and the layout of the interface panel was not designed to be used by a man's hands - everything is very close together with jacks in and out too close to buttons and knobs.

I was a high-end audio salesman for several years, so I am an expert about how things are done in this profit-motivated industry. Regarding amps and DACS, the law of diminishing returns starts at around $300 for the pair. The purpose of this pair is to convert a digital signal from a computer device into an analog signal that is sufficiently loud without detracting from nor adding to the original signal. Solid state amps do the best job at that, as they do not color, distort, mute, and add noises (popping, hissing, clicking, etc.) like tube amps do. As such, a $350 portable JDS Labs O2 solid state amp and Standalone ODAC pairing will achieve 90% to 95% of the audio quality of any $5,000 or even $50,000 setup, marketing spam notwithstanding. I suggest buying them directly from the manufacturer (JDS Labs) for best service. A great alternative pairing is the $199 Schiit solid state Magni 2 amp and Modi 2 DAC combo, but they are not portable and you may have to upgrade to the costlier Uber versions of both (another $120 or so) to achieve compatibility with your equipment. Do NOT worry about the two cheap but state-of-the-art DACS' incompatibility with so-called high resolution files, as there is no audible improvement with them, as per subjective third-party measurements and self-proclaimed audiophile listening tests. Empirical evidence is minimal in the audio industry, which has opened the doors for outlandish manufacturers' claims that rationalize the ridiculously inflated prices of their laughably overhyped yet ordinary products. Third-party measurements of sensitivity, efficiency, frequency response, distortion, and the like are some of the few characteristics that can be objectively measured -- and they empirically evidence every claim made in this review. Everything else is subjective and nothing more than marketing pseudoscience intended to reap the biggest profits for the manufacturers and retailers. I reiterate: professional magazine reviewers are compensated for writing rave reviews for overpriced "high-end" components, which are perpetuated and propagated by barely-literate, unsophisticated, naive blue collar types who post "expert" reviews at so-called audiophile websites. What are the educational credentials of the aforementioned magazine and "audiophile" reviewers, again? Remember, in the audio industry, price is rarely proportional to sound quality.

I do recommend ordering direct to get the options and gain settings that work best for you. I have 2.5 and 0. 2.5 works for when the output of the device or phone is lower and I need more volume. 0 works for line level and where the volume does not need to go so high, It also is more transparent. My HD555/595 are neutral and detailed with my cmoy bb. With the O2 on 0, they disappear. My ath im50 are decent earbuds, I needed something reasonably neutral and blocked out noise. They are good but the bottom is a bit sluggish and bloated. Extension could be better. the character of the bass improved drastically with the O2. The bass got noticeably quicker, tighter. The extreme bottom suddenly appeared. Imaging improved and the top end lost some harshness.It has little sonic character of its own. It does not add bass or make your headphones sound more exciting. It controls the output of your headphones more precisely than your laptop or phone could. That way, your phone or other output does not need to drive the headphones but more easily provides a control signal to the O2, which can more easily drive your headphones in a far more controlled and precise manner. Of course, you can use a DAC or other device as well as the input.

Fine clean neutral sound well suited to quality headphones. Made in the United States and delivered by air within 7 workingdays from their distributors in Japan. Requires an AC/AC power adaptor available from JDS US website duty free within 7 days.Customer service from JDS Labs was excellent.

売価からは想像の付かない程の素晴らしい音がします。最近の高価なハイレゾ対応デジタルアンプと比べると解像度に関しては譲る部分も有りますが、アナログ部分では引けを取らないと思いますので、コスパは最高です。良い物に出会いました！

300ΩのHD650を使用していますがノイズが全くなく、十分な音量が出ます電源端子とinput端子が前面にある点は少し残念です。ヘッドフォンアンプとしてこれ以上の製品は必要ないと思います