• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required as is 20 years of participation in forums (not all true). Come here to have fun, be ready to be teased and not take online life too seriously. We now measure and review equipment for free! Click here for details.

Review and Measurements of Massdrop THX AAA 789 Amp

bequietjk

Senior Member
Joined
Jan 4, 2019
Messages
324
Likes
345
My bad i didnt consider the performance of my dacs outputs.

What i want to clarify is that i find a difference in sound when using the balanced input vs the unbalanced on the 789, but what must also be considered is the performance of the dac being used as time and time again, not all dacs balanced + unbalanced outputs are created equal.
 
Joined
Feb 4, 2019
Messages
85
Likes
72
Location
San Jose, CA
My bad i didnt consider the performance of my dacs outputs.

What i want to clarify is that i find a difference in sound when using the balanced input vs the unbalanced on the 789, but what must also be considered is the performance of the dac being used as time and time again, not all dacs balanced + unbalanced outputs are created equal.
Performance is (in 99% cases) FR, power/clipping/loudness, channel imbalance/crosstalk. You have to consider which one changes when you compare A to B. If for any reason you end up with just "listening" you have to make sure your loudness is normalized. Otherwise it's impossible to compare anything just by listening.

edit: lol lowndness
 

Rottmannash

Senior Member
Forum Donor
Joined
Nov 11, 2020
Messages
433
Likes
240
Location
Nashville
My chain is PC via Audirvana > D70 > balanced to THX 789. Typically listen balanced to HP's and the power on gain 1 and gain 2 is very impressive, even with power hungry cans. Have never used gain 3. Have never sent the signal from the DAC to the amp unbalanced so can't speak to that.
 
Joined
Nov 27, 2018
Messages
47
Likes
11
Hey guys, after I turn on my 789 amp, is it normal to hear one click sound followed by the led signal turning on? ONLY 1 click sound. I thought the click was to show it had turned on right. I have been using it fine since early 2019

Because I was on another thread for another amp, the L30. I said both the L30 and THX 789 made one click noise after turning on. I was told clicking noise in amps are bad and could mean they're broken and could lead to headphone damages
 

raistlin65

Major Contributor
Forum Donor
Joined
Nov 13, 2019
Messages
1,563
Likes
2,191
Location
Grand Rapids, MI
I'm quite enjoying my 789. It addresses the main reason I decided to upgrade over my Atom amp: the THX 789 does not want to fishtail all over the place when plugging and unplugging headphones. I also like the volume knob better because it's longer (I have big fingers). And I'm enjoying not having to unplug my headphones to listen to my speakers or even having to turn the 789 on. The passthrough is a plus given I didn't need preamp capability.

Sonically, for $100, the Atom is the better choice since there is no audible difference. But I am happy with spending the extra money for the THX 789 from a user-friendliness perspective.

BTW: Using the Tempotec Sonata HD Pro as my DAC. Works great with the THX 789.
 

Veri

Major Contributor
Joined
Feb 6, 2018
Messages
6,674
Likes
7,844
The only things I disliked about the knob is the low weight, and eventual scratchiness at initial turn. Otherwise it's a fine amp indeed.
 

Veri

Major Contributor
Joined
Feb 6, 2018
Messages
6,674
Likes
7,844
No scratchiness for me. Maybe yours need some deoxit.
Oh yeah good to bring that up, that fixes the issue right away, indeed :) My past amps did not develop this issue though. Maybe dust collects somewhere, I'm not sure of the cause.
 
Top Bottom