Topping A90 vs THX 789: Review and Comparison

Amplifiers are useful when you need more sound from your speaker or headphone. You can find various brand amplifiers in the market and they are all good to satisfy your needs. From so many, amplifiers we are going to compare Topping A90 vs THX 789 and find out which one is the best for you.

If you see the details of these two amplifiers then you can find so many differences. They have differences in dimensions, weight, frequency response, output power, impedance, and other features difference. But both of them have their own unique features and can provide the best service. They also have a big difference in price.

Comparisons Table between Topping A90 vs THX 789:

General Specifications:

SpecificationsTOPPING A90THX AAA 789
Product Dimensions14.57 x 5.91 x 3.94 inches8.3 x 9.1 x 2.2 inches
Product Weight4.62 lbs3.4 lbs
Frequency Response(+ 0.01 dB) - 0.03 dB 20 Hz to 20 kHz;

+ 0.05 dB / - 0.15 dB 10 Hz to 50 kHz
0.05 dB 20 kHz to 40 kHz;
0.1 dB 20 kHz to 40 kHz;

Balanced Output Specifications:

SpecificationsTOPPING A90THX AAA 789
Output Power7600 mW x 2 @ 16 Ohms THD + N < 0.1%
6400 mW x 2 @ 32 Ohms THD + N < 0.1%
1000 mW x 2 @ 300 Ohms THD + N < 0.1%
500 mW x 2 @ 600 Ohms THD + N < 0.1%
6000 mW, 16 ohms, <1% THD
6000 mW, 32 ohms, <1% THD
800 mW, 300 ohms, <1% THD
400 mW, 600 ohms, <1% THD
IMD-110 dB at SMPTE4:1 @ 60 Hz to 7 kHz
-115 dB at SMPTE1:1 @ 60 Hz to 7 kHz
-118 dB CCIF @ 18 kHz + 19 kHz
-123 dB, SMPTE 70 Hz + 70 kHz, 300 ohms: 0.000071%
-124 dB, DFD 18 kHz + 19 kHz, 300 ohms: 0.000063%
Channel Cross Talk-102 dB at 1 kHz-127 dB, 300 ohms: 0.000045%
Output Impedance< 0.2 Ohms< 0.1 Ohms
Gain-3.5 dB @ G = L
6.0 dB @ G = M
15.5 dB @ G = H
0.66x , 2.0x, 6.6x (-4, +6, +16 dB), selectable via front switch
SNR138 dB @ MAX OUT 1 kHz A - wt136 dB, 300 ohms, <1% THD

Single-Ended Output Specifications:

SpecificationsTOPPING A90THX AAA 789
Output Power3300 mW x 2 @ 16 Ohms THD + N < 0.1%
2000 mW x 2 @ 32 Ohms THD + N < 0.1%
250 mW x 2 @ 300 Ohms THD + N < 0.1%
125 mW x 2 @ 600 Ohms THD + N < 0.1%
3000 mW, 16 ohms, <1% THD
1800 mW, 32 ohms, <1% THD
200 mW, 300 ohms, <1% THD
100 mW, 600 ohms, <1% THD
IMD-110 dB at SMPTE4:1 @ 60 Hz to 7 kHz
-115 dB at SMPTE1:1 @ 60 Hz to 7 kHz
-118 dB CCIF @ 18 kHz + 19 kHz
-117 dB, SMPTE 70 Hz + 70 kHz, 300 ohms: 0.000141%
-125 dB, DFD 18 kHz + 19 kHz, 300 ohms: 0.000056%
Channel Crosstalk-106 dB at 1 kHz-90 dB, 300 ohms: 0.003162%
Output Impedance< 0.1 Ohms< 0.05 Ohms
Gain-9.5 dB at G = L
0 dB at G = M
9.5 dB at G = H
0.33x , 1.0x, 3.3x (-10, 0, +10 dB), selectable via front switch
SNR141 dB @ MAX OUT 1 kHz A - wt136 dB, 300 ohms, <1% THD


Ultra-High Performance

The warmth of the detailed audio that you get with the TOPPING A90 is out of this world. The type of audio that it transmits is realistic and the bass is punchy enough that it will send a shudder down your spine.

Moreover, its compatibility with all the headphones of different sensitivity levels and impedances is what makes the TOPPING A90 one of the best headphone amplifiers in the market.

The TOPPING A90 may not be easy to use nor is it the most efficient of devices but it can sure pack a punch when it comes to bass delivery. No matter the type of headphones or earphones you are using, the output is strong enough to be felt and be amused by it. It costs a tad bit too much at a whopping  $499.99 but why compromise when it comes to performance? Get yourself one.

Points for Praise about the TOPPING A90:

  • No sound distortion at any volume level, making your listening experience the best.
  • Excellent build quality that will make it last for a long time.
  • Gives impressive bass, rhythm, and timing for anything you listen to.
  • Has three headphone jacks and can be used with almost all kinds of headphones.
  • The Black and elegant exterior enhance the look of wherever you place it.

Points for Improvement about the TOPPING A90:

  • The volume dial feels a little too loose at some levels.
  • No remote for controlling it from anywhere.


Compatible and Compact

The THX AAA 789 is a drop collaborated product and that alone speaks for itself. The quality, integrity, and consistent performance it delivers is off the charts. You are getting a sleek looking device with all of the latest technologies remastered and future proof for you to use and the best part yet is the price.

At only $320 the THX AAA 789 is one of the best, affordable headphone amplifiers in the market.

You get the punchy bass, the airy audio quality, and a cool design, packed in a small form factor. The device does not get too hot upon prolonged usage, the THX AAA technology ensures minimum energy wastage, and all in all, it is a great device that is power efficient in every sector.

This headphone amplifier sure lives up to its THX branding. The quality may not be as good as the TOPPING A90 but at that price point, the performance is more than enough.

However, if you want to find out quite a cheap AV preamps, then it is the right article for you.

Points for Praise about the THX AAA 789:

  • Amazing stutter canceling capabilities to give error-free audio.
  • The nonexistent noise floor makes every song sound fantastic.
  • Do not become hot to the touch over extreme levels of usage.
  • The state-of-the-art AAA technology of THX ensures minimum energy wastage.
  • Easy to use infrastructure and controls

Points for Improvement about the THX AAA 789:

  • The audio is tinny and does not feel real enough.
  • The volume needs to be adjusted all the time whenever you are switching from music to podcasts as the appropriate volume for music is not suitable for podcasts.

A little about headphone amplifiers:

Headphone amplifiers are no different than your standard amplifiers. They give you the customizability, tuning capability, and flexibility to get what you want, how you want. Amplifiers need a little studying to get into but once you have the gist of it, the process is simple and you can transition between headphones anytime you want. In this way, amplifiers are an investment and many are willing to go the long way to get themselves one.

With an amplifier, the game is changed as you are in control of the frequencies, amplitude, and voltage that goes into and out of your headphones. Headphone amplifiers come in all shapes and sizes.

Most audio engineers usually have one set right in front of their studio monitor for easy tuning and setting up. With an amplifier, the audio transmitted is raw and it helps an audiophile or audio engineer work easily as the unfiltered sound is crucial for the job.

Aside from that, amplifiers improve your headphone’s performance. If you are reading this article, you care deeply about your music and the wired headphones that you use them with. Increasing their performance is easy with an amplifier or otherwise also known as a headphone DAC (Digital to Analog Converter). You might have seen DACs on many professional-grade headphones and gaming headsets.

Why headphone amplifier

It is true that your headphones might give the best sound quality for anything you watch. But, increase the volume and you can hear quite the crack in the audio coming out. And that is why you need a headphone amplifier! Simply put, it delivers high power to your headphones so that you get the best audio quality even at the peak volume you turn it to.

More often than not, wired headphones are the ones that require an amplifier. If your headphones do not give out the best possible sound when connected to certain devices, it is likely that it is a high-impedance headphone and needs more power to get it going.

That is the main job of the amplifier: to increase the sound of what you are listening to at an acceptable level. In case you feel that your headphones are giving you exactly what you want to hear, then congrats! You probably do not need an amplifier.

Moreover, the quality of a built-in DAC or a headphone amplifier varies from device to device.No matter how decent the amplifiers might be in these devices, it does not compare with the performance and horsepower you will get when using a third-party headphone amplifier. These are small and do not take up much of your space. You can get them at a reasonable price but buying a headphone amplifier is an investment in the future as you will not be needing one for a long time.

Now, who needs an amplifier?

Those with a high impedance headphone. Impedance refers to the resistance of an electrical signal and is measured in ohms. The higher the impedance, the more resistance a pair of headphones or speakers will give to an electrical signal.

For headphones, this value can vary from around 16 Ohms to as high as around 600 Ohms. Generally, a high impedance headphone can benefit most from a headphone amplifier.

Additionally, with a good amplifier, a good signal path or a signal chain is possible to produce. These terms are quite familiar with audio engineers and professionals but the main gist is, the higher the signal-path quality is, the higher the sound quality will be. When matched up with a good pair of headphones, a headphone amplifier can do wonders even your ears will be surprised.

A good amplifier can do wonders and it is essential that you invest your time, effort, and money searching for a good one. To your convenience, this article has done that for you and also boiled it down to two of the best headphone amplifiers you can get at a reasonable price; the TOPPING A90 and the THX AAA 789.

These two are some of the better-looking amplifiers with great versatility.

Read on to know more about the differences and the characteristic features of each and who knows? Maybe by the end of your read, you may find yourself on the checkout page buying one of the two amplifiers in the discussion.

About the TOPPING A90: An Overview

When we talk about Topping products, the Topping A90 is definitely one of the best out there. Coming with a sleek black look, it is bound to make you pause and take a good look at it. Not only does it look good, but it is also very versatile and the three output headphone jacks are the first to prove that.

It can easily adapt to most headphones because of its low noise level of around 0. 2uVrms.

On the topic of volume, let us talk about sound quality. Once you attach this amplifier, your headphones will give you an audio experience like no other!. Be it movies, songs, or games, you will hear every single footstep and bass, and that is magic that Topping A90 Amplifier creates for you. It is guaranteed that you will not hear any distortion at any level of frequency!

All in all, the Topping A90 is guaranteed to make you feel the difference between a headphone with and without an amplifier. The flawless sound at all frequencies and the perfect adaptability to your headphones will surely make you fall in love with it!

Some of the features of the TOPPING A90

●     Sturdy Design and Build Quality that is not a fingerprint magnet

The very robust and compact design of the TOPPING A90 will take you by surprise. The build quality of this amplifier is so high, you can almost mistake it for the premium builds and other high-end amplifiers.

Moreover, the product does not even feel cheap to the touch as it feels like it is made of a whole Aluminium block. The unit is astonishingly heavy in the hand and is just as heavy as one would expect, but it is also well balanced all throughout the device.

The metal finish is subtle and does not track your fingerprints, not that you will be needing to touch the TOPPING A90 once it is all set up.

●     Availability of the RCA and XLR inputs as well as outputs

The TOPPING A90 with its compact yet robust design and form factor also has RCA and XLR inputs as well as RCA and XLR outputs. This unit can be used as a preamp and the addition of these inputs as well as their respective outputs changes the whole game entirely with the customizability and the capabilities of the TOPPING A90.

Moreover, there is also a little bonus of the IEC plug for those who actually need it. The design of the unit is so convenient you even get the ON/OFF switch right beside it for your ease.

●     Ultra high-performance NFCA modules

The TOPPING A90 is the first in implementing and testing out the first member of the very new NFCA module series. NFCA stands for Nested Feedback Composite Amplifier to provide excellent DC and AC performance.

The TOPPING A90 also included the Voltage Current Hybrid Feedback architecture along with the UHGF which stands for Ultra High Gain Feedback. These two architectures along with NFCA also contribute to the added performance in both AC and DC making it safe for both inputs.

●     High output current drive capability

The TOPPING A90 features a special function called the high output current drive capability. This allows the amplifier to drive low impedance headphones with ease due to the high output current support. The low impedance headphones require the amplifier to deliver a high current to support the low power of the headphones and deliver the utmost performance.

Moreover, the TOPPING A90 also features the state-of-the-art low noise value of 0.2 UV which provides an absurdly high dynamic range of 145 dB with no audible noise and the darkest background that is suitable for the most sensitive of the IEMs.

●     Wide Range of Adaptation to Headphones

The TOPPING A90 features a Single-Ended output or SE which is labeled on the device at 25 Vpp and a balanced output at  49 Vpp. This high output voltage along with the high output current as discussed in the previous point helps not only drive low impedance headphones but also a wide range of other headphones as well.

The output impedance being less than 0.1 Ohm not only adds to the flexibility but also to the performance of any headphones that you pair with the TOPPING A90 so fire away whatever device you have as the TOPPING A90 will push that to its limits without damaging anything but rather enhancing the device in performance.

About the THX AAA 789: A Deatiled Scenario

The THX AAA 789 holds possession of one of the most groundbreaking technologies of the company. With the THX Achromatic Audio Amplifier (AAA) and the feed-forward topology, you will listen to the most flawless sound ever!

The distortion rate is reduced by a significant number of 20 to 40 decibels to give you a realistic audio experience for whatsoever you are watching or listening to.

Speaking of superior quality, we have to mention the sound it gives out. Once you connect your headphone to the 789, you will realize how magnificently clear it sounds. Every single footstep of the enemy and every single note of your favorite songs will not miss your ears! In fact, the treble on this will almost make you feel like you are inside the screen, living the experience.

Lastly, if you are someone who is tired of your devices breaking down, the THX AAA 789 will surely live up to your expectations. Made of the finest materials, it will stay by your side, giving you amazing audio for the longest time. It might not be the thinnest amplifier, but it sure looks good wherever you place it!

Some of the features of the THX AAA 789

●     Minimalistic design with a strong form factor and a matt finish

The THX AAA 789 when first released was not as appealing as it is now with the collaboration with DROP. This headphone amplifier will not only catch your eye but also make you want to carry it around. The all-metal form factor is cold to the touch and the matt finish just simply adds to the appeal of the device.

Moreover, the THX AAA 789 is also sturdy and heavy with all the features that are packed into this compact and elegant design. So when you have a headphone connected to the device and you just walked away from the table without disconnecting yourself, the THX AAA 789 will not fall off easily as you will feel the tug of its heaviness.

●     Low bias class AB main amplifier and an auxiliary error correction amplifier

In the THX AAA 789, it has a special feature called the auxiliary error correction amplifier. As the name suggests, it provides a real-time low power error correction signal. This corrects all the distortions that a sound signal may contain and transmits them to your headset.

This auxiliary error correction amplifier works together with a low bias class AB main amplifier. This amplifier is responsible for providing the majority of the power to the signal. Through this, the auxiliary error correction amplifier works.

And both of these work collectively together inside the main THX AAA 789 unit to nullify all distortion units from the transmitted signal for a clean and crystal clear audio.

●     Low Quiescent Current capability

THX AAA 789 features a stunning, state of the art low quiescent current mode that is used to minimize any power wastage. This calls for efficient power delivery throughout the device components with little to almost no power wastage.

You get a clear sound with no distortions and the headsets that are connected to the THX AAA 789 will get a clean power delivery. Another additional feature along with the low quiescent current capability is the multiple gain level settings that help optimize it for headphones and earphones.

●     The flexibility of connecting headphones with various impedance levels

The THX AAA 789 does not have the title AAA for the kicks. The AAA stands for the flexibility of the amplifier to connect and drive any headphones including but not limited to high impedance, high current, and high sensitivity type of headphones.

The various compatibility gives THX the AAA standard. Additionally, this amplifier also transmits audio in its purest form that is almost raw and so makes it suitable for professional work. Raw audio is something that is rare from amplifiers and is greatly appreciated by audio engineers and music producers.

●     THX AAA Technology

This technology is not something to be taken lightly. The high standard of the device and the heaviness that you feel when you hold the device is because of all of these features. THX AAA technology reduces harmonic, intermodulation, and crossover distortions.

A conventional amplifier is highly likely to distort significantly when driving current to a headphone or earphone producing crossover distortions that will fatigue a listener. This issue is something that is often overlooked and arises after usage.

The THX AAA technology solves this problem without letting the heat and weight get in the way. It delivers the same performance if not more without changing anything physically but rather functioning efficiently delivering clean and class A audio to your headset or earphones.

Facts and Features: Topping A90 vs THX 789

Fact #1: Type of Inputs – RCA and XLR

●    TOPPING A90

The Topping A90 features an RCA input and output which delivers excellent performance changing the entire game of the amplifiers. This input allows the headphones to connect easily and the number of types of headphones you can connect to becomes boundless.

It also features an XLR input and output but when paired together, the audio quality is not the best as it puts a little pressure on the device even though it enables the TOPPING A90 to be used as input.

●    THX AAA 789

While the TOPPING A90 may feature an RCA input and output, the THX AAA 789 has a full-fledged XLR input and output. This is best for all kinds of headphones be it high or low impedance.

THX AAA 789 has a great XLR and RCA input and output combination that does not stress out the device but rather keeps everything cool and works efficiently. Under these conditions, the output signal delivered to the headphones is clean and balanced giving out the utmost performance even at high levels.

Fact #2: Stress resistivity and Heat

●    TOPPING A90

When stress testing the TOPPING A90, the amplifier under high activity will stress itself out and the device will get warmer to the touch. This is because of the amplifier delivering high voltage output to the headsets that are connected.

Moreover, the all-aluminum body of the TOPPING A90 adds to the heat. The device when running on full activity gets heated up and the entire body gets hot to the touch.

●    THX AAA 789

THX AAA 789 on the other hand is cool to the touch no matter what or how long you use it. When the device is active for long hours with all of its functionalities online, it will stay cool and not raise temperatures.

This is because of the THX AAA 789s low quiescent current capabilities. It eliminates the power wastage and uses that power to be utilized efficiently throughout the other components of the headphone amplifier.

Fact #3: Bass Delivery

●    TOPPING A90

The Topping A90 does not have the packed punch that is needed from an amplifier. The A90 does more than that, its bass is almost alive to the point where you will feel it in your ears. You can hear the decay of the bass strings, the echo, sound, and punch have a higher more valid presence.

The overall sound is not all bad when compared to other headphone amplifiers in the market. The power delivery is sufficient enough to give out a decent bass to the headphones connected to the amplifier.

●    THX AAA 789

The THX AAA 789 on the other hand has a strong punch to the audio. The intensity of the sound is full and bright so much so that you will feel the raw audio in your ears. The headphones that you connect to the amplifier will also provide the utmost bass with no compromises. But unlike the A90, the THX AAA 789 just has the packy intensity and punchy bass going for them.

Fact #4: Sound Delivery

●    TOPPING A90

This TOPPING A90 headphone amplifier has a more realistic sound or some might call it a 3D sound. This term is not scientific by any means but prints a real picture about the audio quality. The wide and warmer depth of field with a large sound stage does wonders to the sound that you can only dream of.

Moreover, the details of the transmitted audio are clear and precise; and with the TOPPING A90 being one of the most user-friendly headphone amplifiers, it aids the customizability of any type of user.

●    THX AAA 789

The THX AAA 789 on the other hand has a rather tinny and 2D sound. These terms might be the best way to describe the type of sound that is transmitted through the outputs. But that does not mean that the sound is all bad.

When listening to certain songs, the THX AAA 789 takes the cake as it is equipped to deliver a certain level of detail that is noticeable and forefront. The audio is surely brighter and a bit more detailed but it is also fatigued so you will have to adjust the volumes.

Upon further testing, it is seen that you will always have to adjust the volumes when switching from listening to music to podcasts. This is because an appropriate song volume level will have an extremely bright sibilance when listening to podcasts.

Final Thoughts

When it comes to the price, the THX AAA 789 takes the cake as it delivers the best price to performance ratio. It is easily affordable for all consumers. As for the TOPPING A90, it is pricey but performance is not compromised. You are getting the best performance there can be at a small form factor.

Author’s Pick: TOPPING A90

So, the decision is up to you and the best way to choose is of course through practical testing. So head on out to your local audio store and test these bad boys out. Take your budget into account and the music that you like or a podcast and surely you will find the right one that fits the profile.

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