[BrotherKathos]

Hello everyone. I just wanted to share another little impression about the THX 789 and its difference I've found compared to a smaller amp like the Audioengine D1. I've got the Audioengine hooked to the THX as a Dac right now since it has rca outs for that. Its getting fed via toslink straight from my pc and I'm listening with some Beyerdynamic DT 770 M Drummer's edition headphones. Its a waiting period until the SMSL M9 gets here in a few days and will be paired with the Schiit Eitr.

Switching from the internal amp on the D1 to the THX is really a big step up in sound quality. The D1 on its own is one of the smoother all in one dacs in the sub $200 category, but the sound just gets taken to another level all together with the THX in the chain. I have to give the D1 credit though as its performing phenomenally as a dedicated dac in this application. The Beyers have never sounded so good. The presentation is very spacious for closed backs and there is very little of that typical Beyer glare or brighness with these.

The mids are a tad recessed, but the bass and treble are not that overemphasized. Its actually a happy change from the Hd6xx I've been listening to for a while now. I've got another Hd6xx on the way for this setup and will be able to compare bettre at that time, but I have to say, this THX 789 has once agin proven itself to be an amp that just works great with anything I've thrown at it. I've yet to find somthing that sounds off or bad with it in the chain. The Beyers are not fatiguing at all in this configuration. Thanks @AndrewM888 for putting out a great product!

 

[MacMan31]

Hello everyone. I just wanted to share another little impression about the THX 789 and its difference I've found compared to a smaller amp like the Audioengine D1. I've got the Audioengine hooked to the THX as a Dac right now since it has rca outs for that. Its getting fed via toslink straight from my pc and I'm listening with some Beyerdynamic DT 770 M Drummer's edition headphones. Its a waiting period until the SMSL M9 gets here in a few days and will be paired with the Schiit Eitr.

Switching from the internal amp on the D1 to the THX is really a big step up in sound quality. The D1 on its own is one of the smoother all in one dacs in the sub $200 category, but the sound just gets taken to another level all together with the THX in the chain. I have to give the D1 credit though as its performing phenomenally as a dedicated dac in this application. The Beyers have never sounded so good. The presentation is very spacious for closed backs and there is very little of that typical Beyer glare or brighness with these.

The mids are a tad recessed, but the bass and treble are not that overemphasized. Its actually a happy change from the Hd6xx I've been listening to for a while now. I've got another Hd6xx on the way for this setup and will be able to compare bettre at that time, but I have to say, this THX 789 has once agin proven itself to be an amp that just works great with anything I've thrown at it. I've yet to find somthing that sounds off or bad with it in the chain. The Beyers are not fatiguing at all in this configuration. Thanks @AndrewM888 for putting out a great product!

The AudioEngine D1 was my first DAC/amp. Then I switched to the Micca Origen+ which I really liked. Especially the form factor and features. Then I got the Aune X7S and paired it with the DAC in the Micca to start. Then I had bought the Massdrop O2+SDAC which is a great little DAC/amp for SE only use. But I still had the X7S and wanted to try balanced headphone out so I started using it as my daily paired with the Grace SDAC and sold the O2+SDAC. Now I have the XLR cable for my HD6XX on the way to go balanced. Once the THX 789 drops again perhaps I'll jump on it this time. Hopefully there won't be any issues with gain knob misalignment and whatnot.

 

[SnowRunner]

Hi Snowrunner,

Thanks for your patience. I hope Massdrop can stock up again soon!

THX AAA is a new, unique version of feed-forward error correction. It overcomes shortfalls of older feed-forward approaches to achieve the ultimate in linearity and minimal crossover distortion.

THX AAA topology is presently covered by numerous active patents in each of the major global countries. Replicating our IP requires a licensing agreement first, else it may be eligible for pursuit as patent or other infringement.

Please don't hesitate to recommend product or company collaborations you'd like to see for AAA in future. Where should this tech be?

Thanks,
Andrew

Hi @AndrewM888 ,

Thanks for your response, thats great to hear that it is under active patents and protected.
Just throwing out some thoughts, I wouldn't mind seeing a 'plus' version for a modest increase in price, where you improve the 789 platform where you can, either through Massdrop or otherwise, considering things like:
-An improved integrated power supply?
-More precise/machined switches with tighter QC?
-A ultra high power version for Planar Magnetic HP's, (eg. the Emotiva A-100 got a cult following for this)?
-Complementary models: eg. ones Integrated DAC's, or a Tube varient (if thats possible with this topology)?

Basically shooting for better sound where you can find it etc. The lifecycle for an amp (in my case) is usually several years, so having an extremely well made and sounding unit is very desirable even if the initial cost outlay is higher.

I would imagine less pretentious audiophile brands would be ideal to collab with, Massdrop, JDS Labs, Chinese brands (Fiio, Aune?) or tech brands trying to improve their audio (like how LG did with their V-series phones), eg. Sonos, Amazon etc. or targeting concert/public space PA systems where massive power is needed with minimal distortion. I'm sure this rabbit hole goes very deep, just would need to find a markets where this level of clarity can be exploited, or at least marketed.

 

[alpovs]

THX AAA is a new, unique version of feed-forward error correction. It overcomes shortfalls of older feed-forward approaches to achieve the ultimate in linearity and minimal crossover distortion.

THX AAA topology is presently covered by numerous active patents in each of the major global countries. Replicating our IP requires a licensing agreement first, else it may be eligible for pursuit as patent or other infringement.

Patents are public, so I hope it's OK if I ask to mention the patents you are referring to.

Accordingly to Google, THX has 26 patents and 4 of which are pending. One of the pending patents is "Amplifier circuit with reduced feedforward current". But it's the only one that seems to be relevant. The patent for "High-efficiency feedforward-error-correction amplifier" was filed in 1983 by a different entity and has expired. So, it seems anybody can make amplifiers with feed-forward error correction without infringing the patent.

 

[AndrewM888]

Patents are public, so I hope it's OK if I ask to mention the patents you are referring to.

Accordingly to Google, THX has 26 patents and 4 of which are pending. One of the pending patents is "Amplifier circuit with reduced feedforward current". But it's the only one that seems to be relevant. The patent for "High-efficiency feedforward-error-correction amplifier" was filed in 1983 by a different entity and has expired. So, it seems anybody can make amplifiers with feed-forward error correction without infringing the patent.

That's an incorrect assertion of the situation and how utility patents work. Patent titles don't dictate coverage. The title is mostly irrelevant. The claims are what matter. I.e how the cat is skinned vs prior art.

THX AAA patents are in effect and not expired.

 

[BrotherKathos]

The AudioEngine D1 was my first DAC/amp. Then I switched to the Micca Origen+ which I really liked. Especially the form factor and features. Then I got the Aune X7S and paired it with the DAC in the Micca to start. Then I had bought the Massdrop O2+SDAC which is a great little DAC/amp for SE only use. But I still had the X7S and wanted to try balanced headphone out so I started using it as my daily paired with the Grace SDAC and sold the O2+SDAC. Now I have the XLR cable for my HD6XX on the way to go balanced. Once the THX 789 drops again perhaps I'll jump on it this time. Hopefully there won't be any issues with gain knob misalignment and whatnot.

I'm a function over form kind of person, so I would not care as much as others is knobs were not lined up perfectly, even though mine are. As long as I can distinguish between gain and the unit puts out sound like no other in its class I'm happy. The sdac should work great with the THX, and personally I'd probably prefer it over the balanced version since i fear balanced dacs would give the signal too much power and cause me to be unable to easily get the correct volume for my personal taste even on lowest gain.

I use the balanced output on my lcd2c and with a SE dac I still many times only get to 9:00 on lowest gain as my desired volume. With more input voltage I'm not sure i would be able to get my desired volume without running into low volume channel imbalance problems. Anyone is welcome to chime in if I'm off base here regarding my assumptions.

 

[alpovs]

That's an incorrect assertion of the situation and how utility patents work. Patent titles don't dictate coverage. The title is mostly irrelevant. The claims are what matter. I.e how the cat is skinned vs prior art.

THX AAA patents are in effect and not expired.

I never said they expired but only one of them is remotely relevant to this amp. And you didn't add any new information. Oftentimes the product packaging or manual says "this product is covered by such and such patents". I tried to find out what patents are in this case but it seems to be a secret, while patents are public.

The 1983 expired patent "High-efficiency feedforward-error-correction amplifier" was filed by Peter Garde of NewSouth Innovations Pty Ltd, not THX.

 

[MacMan31]

I'm a function over form kind of person, so I would not care as much as others is knobs were not lined up perfectly, even though mine are. As long as I can distinguish between gain and the unit puts out sound like no other in its class I'm happy. The sdac should work great with the THX, and personally I'd probably prefer it over the balanced version since i fear balanced dacs would give the signal too much power and cause me to be unable to easily get the correct volume for my personal taste even on lowest gain.

I use the balanced output on my lcd2c and with a SE dac I still many times only get to 9:00 on lowest gain as my desired volume. With more input voltage I'm not sure i would be able to get my desired volume without running into low volume channel imbalance problems. Anyone is welcome to chime in if I'm off base here regarding my assumptions.

Is there a way to compare the X7S and THX 789 side by side? Like can I just split the RCA out from my SDAC into both amps and then just swap my headphones between them?

 

[ayang02]

Hi Snowrunner,

Thanks for your patience. I hope Massdrop can stock up again soon!

THX AAA is a new, unique version of feed-forward error correction. It overcomes shortfalls of older feed-forward approaches to achieve the ultimate in linearity and minimal crossover distortion.

THX AAA topology is presently covered by numerous active patents in each of the major global countries. Replicating our IP requires a licensing agreement first, else it may be eligible for pursuit as patent or other infringement.

Please don't hesitate to recommend product or company collaborations you'd like to see for AAA in future. Where should this tech be?

Thanks,
Andrew

I've been wondering whether this tech can be used in portable, battery-powered DAC/AMP units. Something like a Chord Hugo. If that's possible then that'll be so awesome!

 

[AndrewM888]

I've been wondering whether this tech can be used in portable, battery-powered DAC/AMP units. Something like a Chord Hugo. If that's possible then that'll be so awesome!

Check out the Monoprice Monolith portable with THX AAA-78.

 

[ayang02]

Check out the Monoprice Monolith portable with THX AAA-78.

Thanks for the info, I didn't know this exists. I just quickly glanced over the specs of this unit and it looks like the output for this unit is kind of low. Well, at least this is a portable unit and I hope we'll see more in the future.

 

[Fatdoi]

I can so see MD does a linear power supply for the 789 and Cavalli lines... I'm sure a lot of owners will want a proper psu than using bricks

 

[ayang02]

Just received my amp after 3 long weeks of waiting!

Lovely outer box design


The gain switch looks alright to me.


Love the clean sound out of this amp! I need to find a good DAC to pair with it FOR SURE.

 

[eeagle]

Is there a way to compare the X7S and THX 789 side by side? Like can I just split the RCA out from my SDAC into both amps and then just swap my headphones between them?

Sure, that is what the pass through set of RCA jacks on the 789 is for. Many amps have pass through connectors so a splitter is not required to allow a single source to drive multiple amps. I do this all the time to compare amps and HPs.

 

[MacMan31]

Just received my amp after 3 long weeks of waiting!

Lovely outer box design


The gain switch looks alright to me.


Love the clean sound out of this amp! I need to find a good DAC to pair with it FOR SURE.

Thank you for the pictures. What kind of tactile feel do you get when using the buttons and knobs? Do they feel solid?