After powering the unit up for the first time I experienced a couple of issues. First, there was no audio out of the passive speaker and the gain level was so high as to hear the noise floor. I checked all of the connection to no avail and then powered down the unit. After powering the DUT back up there were no more issues. I haven't tried BT, only the 3.5mm unbalanced input. Listening to my Classic Rock Station off air I found the sound to be well balanced and the level of gain to be very high, (loud without much input). They sound clean with detail and most certainly have wide dispersion. I don't hang my hat on any speakers without giving them time to break in, which is what I'm doing today, (07-06). One thing to note, after a few hours of playing at a med-low level the powered speaker was very hot at the bottom. Far more so than I would have expected and close to a burn potential to people, (I don't keep my finger on something hot so I'm ok). The plastic may not...
Jul 6, 2023
Massdrop x THX Achromatic Audio Amplifier (THX AAA™) 789 and Massdrop x Grace Design Standard DAC powering a Massdrop X Sennheiser HD 6XX
THX AAA Technology The original concept for THX’s AAA technology was developed by Laurie Fincham, Senior Vice President of Audio Research and Development at THX. Fincham, who is well known in the audiophile community, helped introduce the Steerable Line Array technology for speakers and held previous roles at both Kef and Celestion Loudspeakers. According to Fincham, the massive amounts of engineering and research that went into the product was centered on creating an amplifier that would be audibly invisible. Even the name, Achromatic Audio Amplifier (AAA) is an homage to the transparency of the amp - “achromatic” meaning “without color”. Capable of driving any headphone, including high-impedance, high-current, and low-sensitivity types (like planars), the THX AAA 789 amp transmits the original audio in its purest possible form. That’s largely thanks to THX AAA technology, which reduces harmonic, intermodulation, and crossover distortions. Virtually every conventional amplifier distorts significantly when driving current into a headphone, producing crossover distortion that causes listening fatigue. The engineers at THX set out to solve this problem—and to deliver the performance of a class-A amplifier without the heat and weight—and thus THX AAA technology was born. Each channel of the THX AAA 789 amp is equipped with a low-bias class-AB main amplifier and an auxiliary error-correction amplifier, the former providing the majority of the power and the latter providing a realtime, low-power error-correction signal. The two work together to null all distortion. Finally, the THX AAA 789 has multiple gain level settings to optimize for headphone and in-ear (IEM) listening. Additional features of the Massdrop x THX Achromatic Audio Amplifier (THX AAA™) 789 include:
- Frequency response: + 0.01 dB / - 0.03 dB 20 Hz–20 kHz; + 0.05 dB / - 0.15 dB 10 Hz–50 kHz
- Input impedance: 50 kOhms balanced or unbalanced
- Chassis: High-grade CNC-milled aluminum with bead-blasted finish
- Power supply: 24 VDC inline brick, universal input 100–240 VAC
- Dimensions: 8.3 x 9.1 x 2.2 in (210 x 230 x 57 mm)
- Weight: 3.4 lbs (1,520 g)
- Includes switching power supply that handles 100–240 VAC (US plug; adapter needed for global use)
- Manufacturer’s 1-year warranty
Thanks to the Massdrop community, the initial pre-order quantities flew off the shelf. For everyone who wasn’t able to take advantage of the pre-order, you can get in on the next limited run of Massdrop x THX Achromatic Audio Amplifier (THX AAA™) 789 by purchasing it starting 11/13. We couldn’t be more proud of this collaboration with Massdrop, and we’re excited for you, the audiophile community, to experience Achromatic Audio Amplifier (AAA) technology for yourself.