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JDS Labs Assembled Objective2 Headphone Amplifier Reviews

miceblue

A High Performer for a Low Cost, but Don't Mind the Front-Panel!

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Pros: Excellent sound quality, great price/performance ratio, battery and/or AC powered, adjustable gain options, no background hiss, packs plenty of power

Cons: Everything is on the front-panel, low-volume channel imbalance, too bulky to be used as a portable amp, finicky with TRRS jacks

    Without referring to "He-Who-Must-Not-Be-Named's" (A.K.A. NwAvGuy) blog, and speaking from my own listening experiences, I really do think the Objective 2 is a great headphone amplifier. No, I don't think this is the amp to end all amps, but it's a dang good one and it only cost me $156 USD (which includes the Triad brand WAU12-200 AC adaptor). In fact, it can be found even cheaper nowadays from the same vendor, JDS Labs, for $140 (including the same adaptor).         What's in the Package? JDS Labs Objective 2 headphone amplifier, wrapped in an anti-static bag 2 removable, rechargeable Tenergy 9 V nickel-metal hydride (Ni-MH)...
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DSW92

Unbelievable!

Posted

Pros: Noticeable improvement in some cases, very little improvement in other cases

Cons: Everything is on front panel

UPDATE: So, this amp makes the signal just a bit cleaner. It was pretty noticeable on my Q701s, noticeable for general clarity, separation, esp cymbals got a bit clearer. For my HD 558 (w/ foam mod), slightly noticeable, but not that much. For my closed-back headphones->very minuscule, you might notice if you listen really hard. When I bought this, I just needed power for my Q701s so I was surprised the quality actually improved, thus I might have exaggerated my initial impressions a tiny bit. Overall the difference minor even for the Q701, but still pretty noticeable. It's not OH WOW I CAN'T BELIEVE THIS, IT'S LIKE DAY AND NIGHT kind of difference.   I bought this amp for my...
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MrMateoHead

The Little Beast that Laughs at Everyone

Posted

Pros: Does its Job and Does it Well

Cons: Pricey? Even for what you get . . .

Lets see, a battery powered Amp that runs for hours on hours with a charge, or a desktop Amp that can throw almost a watt out and run forever?   I don't know - its sort of both. It is too big to be taken anywhere, but definitely small enough to travel if you want it to. I ordered mine with a black face plate which I think is a little cooler looking.   There appears to be some "mythology" surrounding this amp, some claim it "ruins" their sound quality while others think its awesome. I think its an amp - that is, it takes a signal, amplifies it, and otherwise has no real impact on what you hear. It has no real noise I can detect (except at max gain of 6.5X with nothing playing...
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Accelerator01

It enhances the audio overall, and the performance is affected by the source the most.

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Pros: Good sound to price ratio, Very versatile for modding, Delivers the sound without coloring, enhances soundstage, decently powerful.

Cons: short battery life (8-9 hours), long charge time (12 hrs using 18VAC, 770mA), audio quality becomes source dependent. Not very portable.

This is my first review submission for head-fi, hope that it could provide some comparison and enough information to let you decide whether to make a buy for it. But do remember this review is from my point of view and the ultimate decision is down to your ears to decide.   First few things to start off with here that i believe will be important:   The sound of O2 really depends on the audio source. The fact that O2 is a very neutral amplifier makes it reliant on the DAC and the file formats it is using. For instance, using the DX50 as line out vs. using DX100 as line out, the difference is greatly noticeable. In another instance, my friend tried my O2 using his phone as...
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ag8908

It might not deliver more power than your laptop or phone jack

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Pros: Very accurately reproduces the source signal; I guess it could help if the source's headphone jack isn't strong enough

Cons: Could use more power

The objective facts   Background: I listen to music on a higher-end (purchased for $800) Asus laptop, or my Galaxy Note 2 smartphone. With my SRH940s, the phone sounds better in terms of sound signature, but with my Sennheiser HD800s, the laptop sounds better for some reason. But they're both very close. All of these experiments were done listening to music on Spotify 320kbps; that's how I listen to headphones 99% of the time so that's the only way to test for my purposes.   How I tested this: I connected the O2 amp, with low gain, to my laptop's output jack. I set the volume of the O2 amp to its highest level (in other words, I controlled the volume of the music from my...
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Hi-Fi'er

Excellent in Price Category and Value

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Pros: Light, Gain Switch, Replaceable Battery

Cons: Not Lithium Batteries for More Power or Run Time

I've been reading so many replies and reviews how the O2, Magni and Vali sound the same. After weeks of listening to all of them, (yes I have them all) they are all not exactly the same . I've been using the same music and all else in the system is the same and have only changed the amps. Started with O2, then went to Magni. Yes the Magni and O2 sound very close. The Magni does sound a tad processed and thin compared to O2 but the Magni does have more authority as it is more powerful in comparison even though they all seem to struggle reproducing the source. The O2 is a really nice amp but when compared to the Magni the O2 is better overall, but sound wise when compared to Vali in sound...
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akshayshah12

Neutral Amp. Great Value.

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Pros: Flat sound. tight bass.

Cons: Charging mechanism is pathetic.

It lives upto its name. This ne is a gem as far as neutrality is considered most neautral Amp i have had or tried so far. I have tried HiFi man EF5 Fiio E11, E17 ,little dot mk2 etc. and found them clearly sub par comparing the bar this product has raised for its price. The immediate this one can notice is great improvement in both treble and Bass. Bass is quite tight. Treble is cold and accurate. Might sound little harsh for headphones like ATH50 but suits well enough for HD650. Wanted to try out well known tube amps especially Schiit Valhalla, Bravo audio ocean and the HD650 specialist (as per many folks on forums) Bottlehead crack. Unfortunately they are not easy to find in the part of...
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itsmejulieeye

Best Bang Per Buck Headphone AMP... Period !

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Pros: Sublime Transparent Sound, Price, Build Quality, Adaptability.

Cons: Maybe could have used the source input & PSU inputs at back

1st things 1st I guess ; I tip my hat to the Guy who Designed the O2 & to JDS Labs also for making it ready built. Now I don't know the Guy who came up with this O2 Headphone Amp but if I did I would certainly shake his hand. I don't say this lightly but here it is then ; This little Headphone AMP is quite simply put the best sounding Headphone AMP I have ever heard, PERIOD ! You add in the fact that I imported it into the UK direct ready built by JDS Labs for just under £100 including a UK PSU for recharging & I guess that possibly makes this little gem then truly the best value for money Hi-Fi component I own including any full Size Hi-Fi components in my Linn/ Musical Fidelity main...
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ILoveGrado

Just The Music, Ma'am

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Pros: Neutrality, Definition, Cleanliness (Black Background), Articulation, Speed (PRAT factor), Imaging, Transparency, Power, Value (Price/Performance)

Cons: If you prefer a certain sound signature from an amp, it has no obvious character of its own, therefore it depends on our source and headphone choice

I have always loved the Grado RA1 which uses the high output NJM4556 op amp. It was one of my very first introduction to the world of headphone amping, and for years it was the mainstay of my main listening rig, both desktop and portable. The JDS O2 amplifier is using similar op amp(s) for its output stage ( and doubles it!), thus I found this JDS Labs Objective2 amp to be easily lovable right from the first listen. It does bear a resemblance in sound to the RA1, but it has more definition, cleaner sound, and more power as well.I had owned a lot of affordable amps: the various CMoys ( I have owned most major CMoy version:JDS, Zigis, Penguin Coffee Amp), 3 Channel PIMETA,...
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tdockweiler

Sounds good with everything I own

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Pros: Transparent (duh), Not bright/thin/cold and requires no specific type of headphone

Cons: don't like the inputs on the front

Just a few impressions since nobody really reads these:   All my headphones work well with it. Everything sounds just like it should. Garbage tracks actually still sound like garbage. Very revealing (yes, I know) and if my recording sounds tinny/harsh/thin it will sound like that (unless I'm using the HD-650) without any change Doesn't sound bright (if it does, it's the recording or headphone) and doesn't require a specific type of headphone for good "synergy" (IMO so far). Doesn't sound cold/thin etc. It's warm (sounding) if the recording or headphone is. Some recordings sound like they have all the warmth sucked out. Sounds crystal clear really. It actually might sound...
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