|Standard Objective 2 Headphone Amp|
The Objective 2 was a reference design, engineered and constructed by NwAvGuy and is essentially an "open-source" product. NwAvGuy makes absolutely no profit from the Objective 2 and is not involved in any way with O2 sales, as he states on his blog. The O2 is built and sold from several retailers. Despite different brand names, the Objective 2 is essentially the same (there will be very minor aesthetic and price differences). The O2 is also available in several different flavors. I received my DIY kit from Mayflower electronics, as of this writing the kit costs $95 dollars. It includes all of the necessary components to build a standalone Objective 2 yourself. Another DIY alternative is to purchase the O2 board, and source the electrical components yourself. This method is cheaper, but obviously requires more effort. Other flavors include the already built standalone Objective 2, the Objective + ODAC combo (the amp combined with NwAvGuy's DAC board) and purely desktop versions of the Objective 2 with a 6.3mm port as opposed to a 3.5mm port. As previously mentioned, I purchased the DIY kit, which is essentially the standard $120 dollar Objective 2. This is the model being reviewed.
The Objective 2 is designed and built to exacting specifications, and every single technical aspect is available for review, unlike other amplifier brands who selectively hide specifications. I suggest heading over to NwAvGuy's blog to check out the technical specifications as they are extremely in depth. I will only scratch the surface of the O2's technical specifications only to illustrate the quality of the amplifier.
The problem with many other headphones amplifiers is high output impedance. Many comparable and even more expensive headphone amplifiers have an output impedance of 10-Ohms or more. According to NwAvGuy's blog, high output impedance essentially muddies clarity and dampens bass response. Having side-by-sided the Objective 2 with standard outputs, such as audio outputs from laptops/ portable devices as well as other amplifiers, I agree with NwAvGuy's assessment. The Objective 2's low, 2-Ohm output impedance resolves this problem. The Objective 2 produces an extremely transparent and crisp sound signature, courtesy of it's low output impedance. Unlike tube amplifiers and other solid state amps, the O2 is extremely flat, there is little to no sound coloration, hence the name "Objective." The O2 outputs slightly over 600mW of power. This is enough juice to power any dynamic headphone on the market with ease. The specifications state that the O2 can power headphones anywhere from a 16-Ohm to 600-Ohm impedance. In other words, the Objective 2 has no problem being used with a wide range of headphones, from sensitive IEM's to full sized 300-Ohm + dynamic and even orthodynamic headphones. The only headphones they cannot effectively power are electrostatic headphones. In addition, absolutely no audio hiss or static is present, something I have noticed with other amplifiers. Even with extremely sensitive IEM's, the sound is extremely crisp with absolutely no audible hiss present.
I use the O2 with particularly middle of the road headphones such as Sennheiser HD 280 Pro's, Grado SR-80i's, Etymonic HF5 IEM's, Audio- Technica ATH-M50X's, Sony MDR-7506's etc. None of these headphones technically need amplification from a power requirement standpoint, all hover between the 32-Ohm to 64-Ohm impedance range. However, I detect a noticeable increase in bass impact and overall clarity when using my headphones with the Objective 2. I also use the Objective 2 as a benchmark amplifier when I review headphones, as it brings out the accurate and unaltered sound signature of the headphones that I test and review as a result of it's lack of sound coloration. The Objective 2 is a neccessity for my headphone reviews, and is my overall daily driver for a desktop headphone amp. No matter what amplifiers I purchase or receive in the future, the Objective 2 will always be a part of my review process, due to its precision and sound reproduction accuracy.
The Objective 2 is hands down one of the best budget amplifiers you can buy. Despite it's low cost, the O2 outperforms comparable and even far more expensive amplifiers. It's a simplistic, minimalist design from a electronic and aesthetic standpoint. For audio enthusiasts who demand a quality, accurate headphone amplifier for a low cost, should seriously consider the Objective 2 and Objective 2 + ODAC combo.
CLICK HERE for Mayflower Electronics product page
CLICK HERE for NwAvGuy's blog