Click to view our Accessibility Statement or contact us with accessibility-related questions
Massdrop Objective 2 Headphone Amp: Desktop Edition

Massdrop Objective 2 Headphone Amp: Desktop Edition

Where's the price?
To negotiate the best possible price for our customers, we agree to hide prices prior to logging in.
10.8K requests
Free Returns in USA
Product Description
In 2011, audio engineer NwAvGuy published a blog post titled “O2 Headphone Amp,” in which he outlined his philosophy on defining sound quality and detailed his ideal audiophile circuit design. Our version of NwAvGuy's famous O2 amplifier, the Objective 2 Desktop Edition features updates based on feedback from the community Read More
Want to know something about this product or how to use it?
Ask the community!

May 2, 2020
Do i have to add a DAC to use this amp with the HD 6XX? I need help
May 3, 2020
I am by no means an audio gear expert, but I have the O2 amp and HD 6XX (the combination you mentioned). O2 has a headphone jack (to plug in your headphones), a port (for power), and RCA cable inputs. So, the only possible inputs to the amp are RCA audio cables (For Left and Right channels, in white and red). So, how do we connect the music source to the amplifier? One possible way is, use a 3.5mm to 2-Male RCA Adapter cable. But I am not sure if the audio quality will be clear, since music will be amplified but the clarity will be as good (or bad) as the in-built DAC in your laptop/desktop or phone. It makes sense to buy a DAC, from all the sources I have read. You can buy the 3.5 mm to RCA cable for 9$, and check the audio quality (Frankly, I have not checked it too, though I assume it should work). I am using 2 devices as DAC. End-to-end connections: (1) Laptop (source) -- > Centrance DACport HD (DAC) --> Objective 2 (Amp)--> Headphones (Senn HD 6xx) Apple Mac --> Centrance's USB 'slot' =Centrance= Headphones 'slot' ---> 3.5mm 2-Male RCA Adapter cable to the Objective 2 amplifier --> Headphones. (1) DAP (source and DAC) --> Objective 2 (Amp)--> Headphones (Senn HD 6xx) Shanling M0 (Headphones slot) ---> 3.5mm to 2-Male RCA Adapter cable --- > Objective 2 amplifier --> Headphones. The DAP acts as a DAC since it has a very good DAC chip. I connect HD 6xx directly to it too. It works great (as loud as I can handle, and very clear). I almost don't need an amp.
Jun 4, 2020
What does the "SE" label mean on the output jack?
Jun 29, 2020
Single ended, Not a balanced output...
What are the differences between the different gain models? Which is best for K7XX and which is best for HD6XX?
Dec 24, 2019
The different gain stages are just about multiply the amount of voltage applied and amplifying the initial preamp signal more. Both the hd6xx and k7xx are relatively easy to drive dynamic headphones so both should be okay on the 2.5x/low gain mode of the standard model. It's possible that the 6xx may need to be moved to the higher mode but as the O2 is such a neutral amplifier the gain stages don't change the sound so it's simply a matter of you going "I've turned the volume past half way and it's not loud enough so I'll turn up the gain". Completely up to if you need the extra volume or not.
Jul 2, 2020
What voltage do I need to pick in order to get the European power adapter?
Jul 15, 2020
According to some comments and the product pics it seems like the product isn't available with the EU plug. You can choose either the 120V USA plug or the 240V USA plug. You will either need to buy an adapter or a new power cord and transformer.
Jan 15, 2021
What US power supply should I buy for the 240V - Standard Gain model? They sent me a European power supply for some reason.
Jan 16, 2021
The same thing happened to me. I chose the 240v because I wasn't paying attention.