Massdrop Objective 2 Headphone Amplifier (Part 1) Review

Two month ago I had review the Massdrop Grace Design SDAC here and probably this is the best sounding DAC under US$100 so far. But having this Grace SDAC alone is not complete if I am not stack it with the amplifier on the top of it.

And here it is, the Objective 2 headphone amplifier with the exact dimension with the Massdrop Grace Design SDAC. I think they are build to stack together.

The O2 amplifier package also have the same box style like the Grace SDAC. What makes this special is the greeting from the amplifier designer.

As you can see the name NwAvGuy on this packaging is actually a person's nick-name on some audio forum from long time ago. He had shared this O2 schematic so the everyone can build their own O2 amplifier.

To take the shortcut in the amplifier making process, especially for many people that don't have experience in building an amplifier like this, then this collaboration with Massdrop is the way to get this O2 amplifier directly.

This is the O2 amplifier, considerably a small size headphone amplifier and easy to carry with one hand.

All built material is made from the aluminum. The front panel have the most amplifier control such as power ON, headphone out, LED indicator, volume control and gain selector.

The back panel only for line input via RCA and the DC power input.

There is no 3,5 mm mini jack input, so if you want to connect this O2 amplifier to other common portable source with 3,5 mm jack output, you will need RCA to mini jack converter.

Since I will connect this O2 amplifier to Grace SDAC with the same RCA connector, all I need is a pair RCA cable from Schiit that I had before here.

The unit is included with power DC wall adapter. This adaptor is thankfully not a switching power supply, means it will perform in lower noise and very ideal for audio application like this.

This is how the O2 amplifier when stack together with the Grace design SDAC. Look sleek.

I review this O2 amplifier sound quality combine with Grace SDAC.

I using Xiaomi Mi 8 Lite as the digital source with the USB Audio Pro application to playback the music files on it.

In comparison, I am using the desktop CMOY amplifier and SMSL SP200 amplifier.

The headphones that I am using here is the Sennheiser HD600 and Beyerdynamic T1.

When listening with O2 amplifier, the gain setting is always set to low gain. It is better because no audible noise occurs compares to high gain setting.

My first impression for this O2 amplifier is a very relaxing sound signature. More likely a warm sounding amplifier with extended top end.

The detail on high frequency is very rich yet far from fatigue for long listening session. The treble detail is considerably more natural, unlike SMSL SP200 amplifier which more richer on treble but likely full of sound coloration.

When listening music with rich instruments arrangement with this O2 seems better because the separation between instruments are well arranged. This cannot be achieve with the CMOY amplifier.

The vocal in this O2 amplifier is more forward and center. It seems like the singer singing in front of you. This sound quality really reminds me to the Bottlehead Crack amplifier.

Then I immediately change this O2 amplifier to the Bottlehead Crack amplifier to get the A-B sound comparison. It sharing almost the same sound signature as the Bottlehead Crack amplifier but of course, because the Bottlehead Crack amplifier using vacuum tube as amplification, the sound quality, especially the mid-range still cannot be comparable at all.

I guess having this O2 amplifier on hand still a good choice to improve the sound quality over CMOY amplifier. Even for the SMSL SP200 which is too much detail and coloration. So I think this O2 maybe the answer for more warm sounding amplifier, just like a Bottlehead Crack amplifier.

With this good sound quality review, I hope you not open this O2 amplifier case to see what inside.

This O2 amplifier components layout is messy. Lots of cheap cables jumper everywhere and poor components arrangement.

If you a believer that single short wire will makes sound different, than when looking to this O2 amplifier internal will be a magnet to do some upgrade.

I guess I will do that for sure.

There is also 2 rechargeable battery slot inside. This makes me wondering if I could make this O2 amplifier portable, then stacked with Grace SDAC will be a great portable DAC amplifier combo.

So stay tune for the next post:)

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