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Review and Measurements of Massdrop THX AAA 789 Amp

rajapruk

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I also think THX easily could change the game entirely on speaker amps if they would like to, doing this kind of cheap Massdrop version of Benchmark AHB2. Just power it with a wall-wart to not compete with audiophile sales of AHB2!
 
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helloworld

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I also think THX easily could change the game entirely on speaker amps if the would like to, doing this kind of cheap Massdrop version of Benchmark AHB2. Just power it with a wall-wart to not compete with audiophile sales of AHB2!
$500 equal performance ahb2:p
 

Veri

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I am betting we will see a lot of thxaaa solutions next year. Hopefully topping will use this module.
I'm not sure it's that simple!

Besides, how will thx aaa devices distinguish themselves? If they all perform like this.... :D
 

helloworld

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Besides, how will thx aaa devices distinguish themselves? If they all perform like this.... :D
Why do they need to distinguish themselves? they are basically chips, I guess the real profit for THX is to sell the chip/solution to those cell phone companies.
 

Jimster480

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Can you PLEASE PLEASE test SE performance?

I basically only use SE...

Also please test it with dual outputs and see if the quality drops. I haven't been able to detect any drops in quality (or volume) while driving both my Aeon and PM-2 at the same time.

Otherwise this is a great review. I'm glad to have this 789 even if realistically I couldn't hear a difference vs my O2 (at lower volumes).

But I have noticed now if I turn the volume up, there seems to be no distortion at all.
 

Veri

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Can you PLEASE PLEASE test SE performance?

I basically only use SE...

Do you mean SE output, input..? He briefly touched upon SE amplification performance

index.php

"You simply get copious more power at whopping level of 3.5 watts before clipping." >> the lines fall on top of each other until SE clipping point, so as long as you don't run out of headroom, SE performance is identical.

He has no balanced headphones right now so the subjective testing was all done via SE (as well as the khadas tone board input, connected via SE), showed no audible distortion whatsoever.
 

Coatessey

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Makes me wish I ordered one of these units, here’s to hoping Massdrop offers them again soon.

Thanks again Amir for all of the hard work.
 

maxxevv

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That is some awesome headphone amp there! Thanks again for the great work. Makes me really interested in the Monoprice one with the dual AKM chips now ...

I tested the balanced output with a 50 ohm load already and hence my question. With the higher impedance of your active speaker, it should even have less distortion.

To use it as you want, you would need to build a special cable that splits the 4-pin into two 3-pin XLRs.

They can be bought readily.

https://www.aliexpress.com/store/pr...l?spm=2114.12010612.8148356.68.4b627362OOqEZ4
 

Schackmannen

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@amirm Can you test THD+N vs frequency with headphones as loads as you have done before? Would be interesting to see if this amp still suffers from increased distortion compared to a dummy load.
 

badboygolf16v

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Even with the extra 100GBP I have to pay in the UK for taxes and customs this is still a good buy!
 

rajapruk

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Output impedance is stated much lower in the Massdrop specs than measured:

Balanced Output impedance: < 0.1 ohms
 

wadec22

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Output impedance is stated much lower in the Massdrop specs than measured:

Balanced Output impedance: < 0.1 ohms
output impedance is the only bummer here. my denon ah-d7200 pickup hiss on an o2 amplifier - so they (and some iems) are going to pick it up here as well.
 

FrantzM

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Makes me wish I ordered one of these units, here’s to hoping Massdrop offers them again soon.

Thanks again Amir for all of the hard work.
Same Here!! Now if they could re-Drop it. Any other way to acquire this gem?
 

Veri

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output impedance is the only bummer here. my denon ah-d7200 pickup hiss on an o2 amplifier - so they (and some iems) are going to pick it up here as well.
On SBAF someone said "It's dead quiet with both my Prophile 8 and Layla IEMs" for what that's worth.
 
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