Massdrop x THX AAA™ 789 Linear Amplifiersearch

Massdrop x THX AAA™ 789 Linear Amplifier

Massdrop x THX AAA™ 789 Linear Amplifier

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(47 reviews)
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Stickied
Movies THX Ltd. started as a company with a directive to ensure that upstream quality in cinema audio made it all the way to the audience in the theater. In the movie theater, you need great power in order to get the dynamic range needed for impactful music and action...with a very low noise floor and low amounts of distortion in order to hear crisp dialog and all the detail in the recording.
Measurements Patrick Flanagan at THX is one of those quiet guys who goes about his business with an engineer’s mind and a craftsman’s attention to detail. You may have met him at a Head-Fi meet in California as Jude Mansilla has been able to have him offer some free headphone or IEM measurements to the community on multiple occasions.
We met him at the 2016 SF Head-Fi Meet where he provided us with some measurements of IEMs we were working on:
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THX provides development and certification services to ensure that a whole range of audio products meet objective performance and quality metrics from frequency response to low distortion, with the goal of accurate sound reproduction.
New Technology The Massdrop x THX Achromatic Audio Amplifier (THX AAA™) 789 represents the next chapter in THX contribution to the audio world, where THX provides underlying circuit technology in the gear itself. The new design was born of necessity. THX needed amplifiers to power line arrays of speakers in their facility. Class A topology amplifiers run too hot and are inefficient to run for long periods of time. THX needed the cleanest signal possible, low noise, low distortion, cool temperature, and efficient power consumption. These requirements led THX and SVP of Audio R&D Laurie Fincham to revisit negative feedback designs, figure out how to implement feed-forward correction, and create the quietest, lowest distortion amplifiers.
THX Ltd. At-A-Glance: I. Highest quality sound for the utmost in cinematic experience (George Lucas’ original vision) II. Development and certifications for pro audio and audiophile gear (people like Patrick) III. Technological intellectual property in pro and consumer gear (Laurie Fincham’s amplifier design as an example)
A Series of Fortunate Events If we didn’t talk about Patrick, you might not know that THX is working every day behind the scenes to provide information to companies making audio gear…with and without the THX logo. And if we didn’t meet Patrick, this collaboration might not have happened.
Meeting Patrick at the event pictured above led to our visiting THX and seeing some of the measurement labs plus their demo room. (Fun stuff and just happens to be walking distance from our office in San Francisco!)
Visiting their headquarters led to an invitation for a sneak peek of the THX AAA feed-forward topology during the Rocky Mountain Audio Festival in Colorado 2016. We immediately saw the potential of this amplifier technology when we learned about it’s goals. Hearing the prototype- clean, clear, and natural (not sterile)...we knew that our community would like it too.
THX understands Massdrop’s connection with the headphone audiophile community and our drive to create custom-tailored products. THX collaborated with us to develop and bring this linear amplifier technology to you in this particular package, with the flexibility for in-ear monitors to large headphones. Capable for use in professional audio applications or for the audiophile that demands the most transparent upstream gear possible. This amplifier delivers the upstream quality of your music to your own personal headphone theater- in the comfort of your home or on your desk at work.
Massdrop x THX AAA 789 Linear Amplifier At-A-Glance: I. Lowest THD in class – world class transparency II. Extremely low channel crosstalk III. From low to high power – for your IEMs and your hard-to-drive headphones IV. Flexibility – from single-ended input/output to fully balanced throughput V. Form factor and usability - small, cool, efficient energy consumption VI. High value – high power and best performance at a low price point
By the way, we’re lucky to have Andrew Mason as a member here on Massdrop. Andrew is the THX expert in analog & power engineering who helped implement the THX AAA technology into our final product. If you have some technical questions about the amplifier, Andrew may just be around to answer them!
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Holidays... ruined, thanks Massdrop!
zep483
Holidays...enjoyed? Hopefully! :)
Stickied
I finished the review of this and gave it to my patrons yesterday. I will not be releasing the review until this comes back in stock because 10,000 people foaming at the mouth for X weeks is not a pretty picture. #lifealteringamptech
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If we work on turntables...is that a way to actually bring back the record industry?
ZeosPantera
Please Santa let this amp drop again soon 🙏 I've been good...
FWIW, Andrew Mason from THX posted on Head-Fi today that he hears a new drop of this amp is imminent. I'm still trying to decide between the THX 789 (if it drops in the near future) or saving for a couple more months and getting the Monoprice Liquid Platinum at exactly double the price.
Hi, has anyone had this shipped to Australia? What's the estimated transit time? 1 week after shipping? 2weeks? Cheers
Here is my cable
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My amp is working fine on SE outputs. My source is a topping D50 DAC. Yesterday I made an silver coated copper XLR cable to use with my HD650. Pin 1 left positive pin 2 left negative pin 3 right positive and pin 4 right negative being the default configuration. Using this cable the overcurrent protection get turned on as soon as you increase the volume at all 3 gain settings. Another forum member on Head Find had similar issues which resolved without him knowing the cause.
Audiodoc
A short inside the cable could cause that. See if any of the signal wires/pins have accidentally bridged to either of the ground wires/pins.
mesaone
Yes you were right. I inserted some heat shrink to prevent the strands from accidentally coming in contact with the ground. Now everything sounds great.
Finally got both my Massdrop HD6XX headphone and THX AAA on the same day. Now in the midst of burn in. Will setting to gain 1 and pushing the vol near max help achieve a faster burn in or will that be pushing the amp too close to edge for comfort ?
kiat
Too close to what edge? Cranking the pot to max won't hurt the amp. Just don't damage your headphones.
i'm excited to get this amp. is it ok to have two pairs of headphones plugged in at the same time? one balanced and one SE?
Is there a difference in sound when using single ended and balanced ?
Azeendeen
There shouldn't be. The XLR just provides more power
Hey guys, i placed an order and the unit was shipped out from NJ, USA on the 3rd of Dec to me ( I'm in the Far East ). Was processed in Germany ( IPZ-Ffm ) on 8th Dec ( Transit facility ), since then it hasn't updated and further details shows " The shipment will be transported to the destination country and, from there, handed over to the delivery organization." Has anyone experienced such a lapse between days during shipment so far?
wil84
It's standard, your package is on a truck/train to the destination country and that takes a few days
e.xo
Thanks man. Guess i shouldn't have worried. Amp arrived today!
First time using md...never again. I can't believe shipping is so slow! Ordered 789 on 16nov still not here. Oh well, even Amazon prime shipping takes 2 weeks for delivery.
Finally something that drives my HiFiMan HE-560's effortlessly; 45 ohm 90 SPL planars. The 789 arrived yesterday, the 560's require gain 3 a bit over 9 oclock with the balanced cable.
https://www.youtube.com/watch?v=MIAPJ_1Ruys Very good explanation (good details) and review about THX AAA 789
flanker
The video you linked shows the external features of the amp well, but the reviewer claims this amp is a fully balanced amp. This amp uses op-amps in the signal path and is not fully balanced.
Jude getting some measurements to us...will try to post here as soon as I can!
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I'm glad to hear that you're doing QA on these at the factory. If you trust the factory, that's a good place for QA to happen. I've already seen a couple of reports on head-fi from people who received units that were DOA. Given that and past experience with Massdrop QA, I'm not sure how much *I* can trust the factory, so I'd still be interested in hearing the results of your testing.
burn-in? burn-in? research...
Is it safe to plugin headphones that do not require much power? For example M220, HD58x, PC37x?
notsofast
Yes- you can plug IEMs into this amp!
CEE_TEE
+1! Gain 1 is great for IEMs.
I've had mine for what, a month now? I was impressed immediately after the unboxing and hooking it up. I've done some amp swapping since then, and it is even more impressive after side-by-side, direct comparisons. This is the best amp I've heard, compared it to to amps 2x the price or more, and its still a winner. It is an Awesome Amp and I feel lucky to have one. :-) Word of advice - this amp is so clean, and with such a black background, that you can easily damage your hearing. If you find the amp is a bit bright to begin with, but your 'ears adjust after a while' and then it's not so bright - you may have suffered some loss of high-frequency hearing due to this being so lacking in background hiss - and the loud transients have been hammering your ears (pleasurably perhaps, but still, hammering), so you listen at higher volume than normal. You gotta approach super-clean, powerful audio equipment with a certain degree of caution, and respect...fair warning! <edited for redundancy>
(Edited)
Just received the amp today! At first, it seemed like an accident to me because it costed me USD60 for import tax. And I totally forgot that I had joined the drop and the timer ran out while I was in a meeting! Coming from a Topping DX7s, I can tell that this amp produces sound noticeably fuller than the built-in amp in Topping DX7s. I'm glad that I had this accident! ;D
(Edited)
natthaps
A happy little accident as Bob Ross always says
Does this item ship to Australia
Hi fellows, Just joined the drop. Hoping this amp can feed my Elex and HE4XX well. I am hoping to connect my A&K SE100 to the THX 789 via 2.5mm balanced line-out. First I thought all I need is a 2.5 mm male to dual XLR-3 cable. Something like this:
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But then I read an article from Moon Audio suggesting that :"The grounding scheme of portable players have virtual grounds since they can't be tied to an earth ground. When you connect a DAP to a 2 channel stereo system with a true earth ground, some problems can occur...Just doing a 2.5mm TRRS connector to XLRs can often result in a hum issue." Basically they say in order to avoid such humming issue, a A&K PEE11 balanced adapter is needed. Like this:
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They claimed that "The ground from the 3.5mm is used to tie the ground of the Astell & Kern to the ground plane of the preamp. Just doing a 2.5mm TRRS connector to XLRs can often result in a hum issue. Why? There is no ground plane thus why it causes a grounding issue which results in the hum." Has any one used SE100 or any other DAP's 2.5mm balanced out to a desktop amp? Do I really need the balanced adapter to avoid the humming issue? I am pretty new to the amp world. Any comment is greatly appreciated.  Thanks a lot!!!
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vpn2001
Good find. Wish they'd include a pinout image, but the description seems to match what's required. Prices seem more sane than some customs, as well. Thinking about buying an XLR4-to-2x3.5mm TRS cable as a backup, since the canare starquad I have on hand is too thick for a comfortable headphone cable.
I was going to buy one of these today, can you redrop please!!!
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zep483
I have one for sale. Just received it last week but need a DAC/AMP unit for my system. Perfect in box with zero time on it. Will cover US shipping.
soundsgood
Hi, contact me if your unit is still available for sale. Khuongtrantrong@gmail.com Thanks
how often does this drop?
notsofast
I, too, would like to find an answer to that question. The drop before this one was in May if I remember correctly, and this one started in November. Considering this timeline, it may take Massdrop a while to release another drop. If anyone from Massdrop could give the possible date of the next drop for us, we can adjust our financials accordingly.
Do the balanced output work with the single ended input?
Svperstar
Of course.
well looks like I won't have the money in time for this batch, I hope the next batch is timely
Would like to check if I can do the following configuration DAC->RCA->THX AMP -> XLR output? thanks !!
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I’m using Massdrop M6XX
kiat
Bal in is best if your DAC permits, regardless of headphone. For 6xx you might like bal out for the extra voltage swing. Just be careful not to damage your hearing.
Why are they showing a picture of this amp stacked with the CTH?
Machinery1
To show a common form factor. I'd expect all massdrop "fullsize" equipment to use this footprint when possible. Lord knows it didn't need to be this large, the PCB has a lot of dead space. https://i.imgur.com/l1vR9YM.jpg
Very good little amp, sound perfect make the experience awesome. But you can not use it as a preamp, it's only a pass through.
I'm currently using Modi 3 and thinking about pairing it with the THX AAA. Is there any benefit in upgrading to a balanced DAC just to pair with THX AAA and why? If so, which balanced DAC should I consider?
YYL_1
RCA is fine actually. Balanced is not a big plus with this amp, since the SE and BAL get converted to the same output.
Hello, does anyone had paired it with SMSL SU-8 (V1) using balanced output?
dmitriykutelev
Literally just plugged in this same setup a few hours ago. Definitely hearing some more clarity from my old, fully decked out Burson play. First DAC/AMP so I do not have another combo to compare to.
@AndrewMason Question - (sorry if this is asked ad answered but searching through nearly 2000 messages would be painful!!)... I am driving my MD x THX AAA 789 with a Topping DX7S amp through the XLR outputs of the DX7S. As I understand it, there is a max voltage swing that the 789 can tolerate before it begins to clip in at least the highest gain setting... My question is what output level should I set the D7XS so it dos not cause a problem for the 789 in high gain when I am feeding the 789 with XLR inputs? Somewhere I read that was about -6dbfs... A related question... I really don't want to have to remember to reset the output level of the DAC when I switch gain on the 789... If I set the DX7S to the appropriate level to not clip at 789 in high gain mode and just leave it there for the other gain settings, will that result in any quality loss for the output of the 789 when I run the 789 at low or medium gain? I understand that I will lose some volume headroom, but I am OK with that (and if I ever have a problem with volume at the lower settings I can always raise the output level on the DX7S...)
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-93dB at 1kHz the benchmark frequency, and only on gain "1". That's still super super low. I'd venture its inaudible.
AndrewMason
Excellent, thanks. Bought one of the last units today :) very excited It's very cool btw @AndrewMason that you are so active in the community!!
To anyone who ordered this from Canada. What kind of import/customs fees did you end up having to pay extra?
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That's actually not too bad. I'm in Ontario with 13% HST.
Wallboy
I paid $70 COD at Canada Post 👎🏻