Massdrop x THX AAA™ 789 Linear Amplifier - Impressions Thread
Oct 31, 2018 at 12:38 PM Post #211 of 2,613
They get it straight from US I believe and not through Germany I guess. Mine has finally cleared the customs so with maximum luck I have it on friday :). I just happened to click home a RME ADI-2 DAC. So many useful features in modern dacs my dacs have inputs and a selector for them and power button and that´s it :p
 
Oct 31, 2018 at 4:48 PM Post #212 of 2,613
Booring shopping question. Just curious if any EU customers got their yet? Seems to be boat shopping from germany?

I got my amp delivered last Friday. Perfect working condition and great sound. Not quite AHB2 level, but well above the price range imo.
 
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Nov 1, 2018 at 2:52 AM Post #213 of 2,613
Yes it's no problem to hot plug/unplug 789's XLR-4 headphone cables.

Nice, thank you for clarifying that!

We recommend pausing the audio whenever plug/unplug 1/4" and 3.5mm TRS since they short T-R or R-S every time a user plugs/unplugs. Due to AAA's miniscule output impedance ~65 mOhms, even a tiny audio signal can cause full current >1A to flow through the short which trips the overcurrent protection, shutting the amp down for a few seconds before auto-rebooting.

Pausing the audio is certainly less of a hassle than adjusting the volume or turning it off. Good to know that that is good enough!

Conventional amps with 1-10 Ohm or higher output impedance don't face this problem. Their output impedance limits the current. But of course, Zout > 1 Ohm isn't optimal for fidelity.

The Schiit Jotunheim is specified as having < 0.1 ohms output impedance, but does not come with such a warning. But maybe it should, who knows. :)

The Gustard H20 also has < 0.1 ohms output impedance (as per their revised specs). However, it does not even have a manual that could warn me, so who knows. :-D

It's a good precaution, I suppose. And in its best mode (balanced) it's optional, so that's great.
 
Nov 3, 2018 at 4:26 PM Post #214 of 2,613
Got my replacement and it powered up just fine!

Been listening to it for the last hour and it's certainly preforming as advertised. Very transparent and powerful. Especially seems to like being paired up with my Yggdrasil, which gives it some extra punch and musicality.
 
Nov 5, 2018 at 12:44 PM Post #215 of 2,613
Edit: Panicked got it working. Seems my us to eu adapter is borderline getting connection but it´s working fine now.

Surely appear to drive my Audeze LCD-2 just fine balanced. It´s my absolute favourite headphone so really important. Will have to wait but feels I can do without my bulky Yamaha RDS-440 receiver now.
 
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Nov 5, 2018 at 1:01 PM Post #216 of 2,613
So frustrating... Waiting over 2 weeks for it to ship and now it don´t power on. The brick reads green so it seems to be on the amp side. The power connector fit really loose so maybe something there broken? I read you should pull the power button but I can´t pull mine out at all?
Pulling still helps. My power button doesn't seem to move either when I pull it, but something gets unstuck anyway. It doesn't move, I don't feel anything getting released, there's no particular sound to it... but it works most of the time.

Contact Massdrop support, I got the option to return it for a full refund, exchange it for a new one, or keep it for a 20% discount.
 
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Nov 5, 2018 at 1:25 PM Post #217 of 2,613
Pulling still helps. My power button doesn't seem to move either when I pull it, but something gets unstuck anyway. It doesn't move, I don't feel anything getting released, there's no particular sound to it... but it works most of the time.

Contact Massdrop support, I got the option to return it for a full refund, exchange it for a new one, or keep it for a 20% discount.

Thanks. I hope it was just my adapter but time will tell. I got it working and boy it´s exactly what I hoped for for my Audeze LCD-2. Similar balance as my yamaha RDS-440 but cleaner and absolute blackness. And it seem to have enough oomph in balanced mode to drive it to it´s full potential.

The only thing the noise of the yamaha can somehow sound more analogue and natural I suppose and it adds maybe some warmth so will see what happens but now it seems I can replace it and never look back. But time will tell when they honeymoon period is over.
 
Nov 5, 2018 at 1:38 PM Post #218 of 2,613
Pulling still helps. My power button doesn't seem to move either when I pull it, but something gets unstuck anyway. It doesn't move, I don't feel anything getting released, there's no particular sound to it... but it works most of the time.

Contact Massdrop support, I got the option to return it for a full refund, exchange it for a new one, or keep it for a 20% discount.
curious what you decided to do with them? i sent another message because mine is acting up again. its the button for sure. one thing i also dont like is if you look after a number of presses you can see the sides of the button start to get a bit scratched. at least mine did. it doesnt sit perfectly centered and is rubbing on the left side when pressed. bummer because it sounds really very very good when i can get it to power on. i also have a very low serial number which i personally like but id rather i think have a working unit. lol
 
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Nov 5, 2018 at 1:45 PM Post #220 of 2,613
imo its a bad design with the button like that i would have far preff an actual click. even if it doesnt stay pressed down a nice click would at least (usually) let me know the mechanism is making contact in there. im going to have to ask for a replacement i cant deal with a 350$ product that only works 25% of the time lol
 
Nov 9, 2018 at 9:51 AM Post #221 of 2,613
Hey yall,

I know this is the thread for the massdrop amp, but since I was looking for a more early solution to my lack of good SS amp, I wanted to ask about the amp on Monoprice's site.

Does anyone know if Monoprice has website wide sales? For instance, do you think they might mark down their thx balanced Dac/amp on Black Friday?
 
Nov 9, 2018 at 9:57 AM Post #222 of 2,613
I know this is the thread for the massdrop amp, but since I was looking for a more early solution to my lack of good SS amp, I wanted to ask about the amp on Monoprice's site.

Does anyone know if Monoprice has website wide sales? For instance, do you think they might mark down their thx balanced Dac/amp on Black Friday?

Their THX items are brand new. The desktop amp is still unreleased, the portable thx amp released some days ago.

In general, items than are brand spanking new will not be discounted. There was a sale some days ago (NOV sale) and none of the new items were discounted. Just doesn't make a lot of sense business-wise.
 
Nov 9, 2018 at 4:46 PM Post #223 of 2,613
Just got my THX AAA amp today. I've only been listening to it for an hour or so, but my initial impressions are very positive. The first thing I noticed about the amp was that it seems to reproduce treble in a way that while being clear and pronounced, there is somehow no harshness or discomfort from it. Many amps that I've experienced in the past whether home theater or head fi always seemed to be a turn off since I get discomfort from pronounced treble reproduction. This THX AAA amp is the first amp I've ever heard that gives me no discomfort at fairly loud volumes while not being warm. Granted I probably listen to lower volumes than most as I have been using 3 headphones with it so far all SE on lowest gain .33x and have not needed to get past 2:00 on my most power hungry hifiman he-400i planars.

I would say that the advertisement of this amp being a "super o2 amp" is accurate. The only real difference I notice between my massdrop o2 amp and this one is that there is maybe a bit more dynamic range with the AAA and the treble characteristics that I mentioned earlier. This is the biggest positive for me since I've in the past hated amps advertised as "transparent" like my magni 3 for instance as they just seem to be grainy and harsh. The o2 amp was better than the magni 3, but it would still get a bit shrill to me if you got more greedy for volume. So far this has not been the case with the AAA amp. I'm waiting on a balanced cable for my HD6XX and am looking at my options for my Audeze LCD2C in cables as well. I'm looking forward to testing the difference with balanced vs not as the crosstalk and power ratings look way better. I wonder if I'll actually hear a difference? I'm usually skeptical about these things, but it is possible to change my mind as well due to past experience.


The headphones I've used with the amp so far are Sennheiser HD558 with 598cs earpad mod, Hifiman he-400i with Dekoni fenestrated lambskin pad mod, and stock Audeze LCD2C. These three headphones all paired well with the AAA amp and the Topping D50 dac I'm using as a source. I've not hooked up my HD6XX yet to listen, but will some time later as well. Sound stage and dynamics are only helped with this amp and there does not seem to be any negative aspects introduced to the music in my opinion. My final thoughts are that I would recommend this amp to anyone that is looking for a powerful and dynamic amp that has great bass and very clear and pronounced treble without becoming fatiguing. This amp is an objectivist with sensitive ears' dream. As far as build quality goes I've not experienced any problem with the power button yet as it seems to be lined up correctly. The gain button selector on my unit also lines up properly. The pass through works and is nice since it passes through all the time whether the unit is powered on or off. This lets me quickly switch between speakers and headphones without unplugging or powering off anything. Just turn the volume down on the hp amp, and turn the volume up on my jds labs passive preamp to use my power amp and speakers. Or you if you are really feeling randy, just listen to the headphones ad speakers at the same time? Sacrilege? I hope everyone who decides to get one of these has the same initial experience as me. Great product for a reasonable price :)



Edit: I just tried the Massdrop Senneiser Hd6XX with the thx 789 and in SE with the stock cord they are my favorite headphones with the topping and thx amp. This pairing gets my top recommendation. I'm really glad I've got a balanced cable for the hd6xx on the way now!
 
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Nov 9, 2018 at 5:55 PM Post #224 of 2,613
Some days in and yes it´s a good amp for sure. And no issues at all just my us to euro power adapter surely. It don´t discriminate any of my headphones but Focal Elear still just must have my Trafomatic Audio Head One. It´s a mediocer headphone on anything else but still for solid state the THX 789 is the best try so far for it.

Another tricky headphone that needs control is the DX 1000 and yes it works sublime here. Strong competitor to my Goldpoint Headphone Pro. I dare not to say what is better or worse yet.

Sennheiser HD 800S. Here I am quite sure this is number one. I didn´t expect this I expected to preferr my Trafomatic Audio Head One maybe it´s the smooth treble that hugs the ears some more that make it work better for me I don´t know.

Audeze LCD-2 in balanced mode I can´t dream of it being underpowered either. It goes toe to toe with my giant killer. My Yamaha RDS-440 for 20$. I would say the RDS-440 do have a more natural tone to it. THX 789 comes across as a bit of modern digital sound but will see once I got used to it. That digital sound do sound expensive most of the time :wink:
 

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