The Objectivist’s DAC/Amp

For the objectivist audiophile seeking a complete desktop solution, there’s the Massdrop O2 + SDAC: a DAC/amp that brings two great products together in one affordable, easy-to-use package. It features the Massdrop Objective 2 (or O2), the community’s favorite solid-state amp, alongside the Massdrop x Grace Design Standard DAC (or SDAC), a collaboration with a company long known for its incredibly accurate, transparent studio gear. The result is an all-in-one unit that measures objectively well and works with a variety of headphone impedances. Plus, its small form factor is designed to stack with the Massdrop × Cavalli Audio Liquid Carbon X Amp and other Massdrop Made audiophile products.

Drop O2 + SDAC DAC/Amp

About the Massdrop x Grace Design Standard DAC

The Standard DAC sets a new standard in entry-level DACs. Designed with the objectivist audiophile in mind, the SDAC delivers objectively good performance meant to meet or exceed the measurements of the popular ODAC while retaining many of its other benefits. It’s equipped with the new AKM AK4452 digital-to-analog conversion chip and can process the most common file types up to 24 bit/96 kHz with no harshness or edge and the kind of resolution and detail that’ll make you want to listen on and on. It runs off of USB bus power with plug-and-play operation, which means you won’t need drivers or any special software to get started.

Drop O2 + SDAC DAC/Amp
Drop O2 + SDAC DAC/Amp

About the Massdrop Objective 2 Headphone Amp

From 2011 to 2012, anonymous audio engineer and blogger NwAvGuy created some of the DIY audio community’s most popular designs—then as quickly as he entered that world, he disappeared. The Objective 2 is his most famous headphone amplifier, based on his sound quality philosophy and ideal circuit design as published in his 2011 post, “O2 Headphone Amp.” Made for benchmark performance at an entry-level price, something the community hadn’t seen before, the O2 is an excellent, no-frills baseline reference amplifier. It’s capable of powering everything from IEMs to the Sennheiser HD 800.

Drop O2 + SDAC DAC/Amp

About the Jack Configurations

On the back of the device, you'll see a single set of RCA jacks labeled with symbols for both input and output. When you're using the USB input, the RCA jacks act as an output from the SDAC. If you disconnect the USB, you can connect analog input from your favorite DAC straight to the O2.

Drop O2 + SDAC DAC/Amp
SDAC Only: Frequency response, 20Hz–20 kHz:
SDAC Only: Frequency Response Deviation
SDAC Only: THD+N at 20 Hz -0.15 dBFS
SDAC Only: THD+N at 100 Hz, -0.15 dBFS
SDAC Only: THD+N at 10 kHz, -0.15 dBFS
SDAC Only: IMD CCIF, -6.03 dBFS, 19/20kHz, 24/96k
SDAC Only: IMD SMPTE -6 dBFS, 24/96k
SDAC Only: Noise, A-weighted
SDAC Only: Dynamic range, A-weighted
SDAC Only: Crosstalk at 1 kHz, -10 dBFS (3.5mm jack)
SDAC Only: 1kHz Sine
SDAC Only: FFT – Left
SDAC Only: FFT – Right


DAC Section

  • Massdrop x Grace Design
  • DAC chip: AKM AK4452
  • Audio formats: Up to 24 bit/96 kHz
  • Frequency response, 20Hz–20 kHz: +/-0.02 dB
  • THD+N at 20 Hz -0.15 dBFS: 0.0013%
  • THD+N at 100 Hz, -0.15 dBFS: 0.0013%
  • THD+N at 10 kHz, -0.15 dBFS: 0.0024%
  • IMD CCIF, -6.03 dBFS, 19/20kHz, 24/96k: 0.0005%
  • IMD SMPTE -6 dBFS, 24/96k: 0.0015%
  • Noise, A-weighted:  -105 dBu
  • Dynamic range, A-weighted: >114 dB
  • Linearity, -90 dBFS: -0.07 dB
  • Crosstalk at 1 kHz, -10 dBFS (3.5mm jack): -102 dB
  • Sum of jitter components at 11,025 Hz, -1 dBFS: -133 dB
  • Maximum output:  2.15VRMS
  • USB controller: XMOS XU208-128-TQ64
  • Inputs: USB micro
  • Output: RCA
  • Power: USB Class 1 (no drivers required for Windows, Mac, or Linux)

Amp Section

  • Input: RCA, SDAC (when powered)
  • Output: 6.35 mm
  • Power: AC adapter included (purchase separately: plug adapter for your country’s outlet)
  • Gain: 1.0x and 3.3x
  • Frequency response: +/-0.1 dB (20 Hz–20 kHz)
  • THD (1 kHz, 150 ohms): 0.0016%
  • IMD CCIF (15 ohms): 0.001%
  • IMD SMPTE: 0.002%
  • Noise (ref 400 mV): -105 dB
  • Max output (33 ohms): 613 mW
  • Max output (150 ohms): 355 mW
  • Max output (600 ohms): 88 mW
  • Output impedance: 0.54 ohms
  • Crosstalk (15 ohms): -65 dB
  • Channel balance (50% volume): 0.6 dB


  • Front ¼ in (6.35 mm) output
  • Rear RCA input/output
  • Rear microUSB
  • Rear power
  • Chassis material: Anodized aluminum
  • Case dimensions: 4.12 x 3.87 x 1.12 in (10.46 x 9.82 x 2.85 cm)
  • Weight: 9.28 oz (263 g)


  • 3.3 ft (1 m) micro-USB to USB cable
  • Drop's 1-year warranty


We get it. Sometimes what you ordered just doesn’t work out. If that’s the case for you, don’t fret! All customers (both US and international) may return this item in new, unused condition within 30 days of delivery.


Estimated ship date is Oct 1, 2021 PT.

Payment will be collected at checkout.

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User Photos55
Hung right in with the DM Source!
Easily mounted under my desk. Super easy to access.
Mounted under desk, with some 3M Dual Lock tape. I have a mod-mic wire pinched between the DAC Amp and desk, and the 3M strips hold it no problem. The unit is pretty light.
Goes well with the Dt990 pro 250 Ohms
I like to see what I am buying :)
Compact size
Nice little package
6XX Driver
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