“ 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...” --miceblue
“ Okay, a serious question not related to the review: what is the difference between the "Audio Quality" rating and the "Quality" rating, and how is the "Quality" rating different from the "Design" rating? *scratches head* Anyway, back to the review. I did a video review for the C5 on YouTube if you are interested in an auditory/visual...” --miceblue
“This review is based on matching the Mini X with Hifiman He-500 Headphones. You may be reading this review, unsure what to make of this Amp, asking how can a cheap sub $200 amp offer the power needed for an expensive Headphone such as the Hifiman He-500? If you have done your homework you will find this is the stereo amp everybody is...” --fluidz
“This was provided to me from JDS Labs as a free review unit, so I need to give a big, big, big thank you to JDS Labs for their generosity! You might be able to see in the photos that my unit has some blemishes in the aluminum case. These will not appear in normal units. Since Head-Fi doesn't display the rating details from the reviewer, but rather the community average, here are my...” --miceblue
“ The JDS Labs O2 + ODAC combo (and just about every other version) is built into a simple metal enclosure (mine is black) and all of the inputs and outputs, save for the USB input are located on the front of the device. Aesthetically, I don’t love that design decision but I understand it’s one that was likely made due to the O2 being designed originally as a portable (sort of)...” --TheGame21x
“Amazing sounding amp, easy to charge with a mini USB, bass boost works really well without muddying the sound, low/high gain switch. Sounds better than any other amp I have tried, ie Fred Fred cmoy and fiio e7 ” --Mkvy
“ ****Note**** As always, these are strictly my opinions. I try to present these products as honestly as possible and try to describe them as best as possible. As always, YMMV. ****NOTE**** FISCHER AUDIO MYSTIFY PORTABLE HEADPHONE AMP SPEC’S: Frequency “flatness”: +/- 0.5db Dynamic Range: 110 db Total Harmonic Distortion: 0.001% Intermodulation...” --LFF
UPA-200 represents a true breakthrough in audiophile-quality amplification. At last, a truly affordable stereo power amplifier that can satisfy the most discerning aficionado, and at the same, is affordable to anyone with a desire for real quality. Our advanced engineering and design techniques have resulted in an amazing new amplifier. Its rock solid performance and affordable price point...
Taken for item page: "The Objective2 (O2) is an open source headphone amplifier designed by NwAvGuy, with emphasis on benchmark performance and low cost. This item includes a preassembled and hand tested O2 circuit board, ready for use. You will also need an enclosure and AC adapter. The O2 has created a stir in Head-Fi.org’s do-it-yourself community. After posting one too many ...