SMSL T2 Tube Headphone Amplifier: A 2023 Review

Listening to music is one of the ways by which people relax and forget about what is going on around them for a while. People who love music usually use headphones so that they can listen to the lyrics of the song, as well as to clearly hear the background music.

For a better listening experience, they also use headphone amps like the SMSL T2 2X6J9 Super Low Ground Noise Vacuum Tube Headphone Amplifier.

Headphone Amplifiers

Amplifiers, in general, are products that are designed to improve the power of level of the sound being produced. Headphone amplifiers are usually integrated into cellphones, computers, iPads, mp3 players, and other electronic devices that have headphone jacks.

But people can already find headphone amplifiers that are sold separately wherein both electronic devices and headphones can be connected.

There are several types of portable headphone amplifiers and one of which is the so-called vacuum tube headphone amplifier. But what are vacuum tube headphone amps?

Vacuum Tube Headphone Amplifiers

Tube headphone amps are electronic products wherein two or more vacuum tubes are used in order to produce a sound that has an increased power level. Since they have pure and straightforward circuits and good sound distortion capabilities, many music lovers prefer to use them over the other types of amplifiers. Hence, the increase in the demand for vacuum tube headphone amplifiers.

An excellent example of such headphone amplifier is the SMSL T2 2X6J9 Super Low Ground Noise Vacuum Tube Headphone Amplifier. So, let us now try to learn more about this product.

SMSL T2 2X6J9 Super Low Ground Noise Vacuum Tube Headphone Amplifier

This is a vacuum tube headphone amplifier that is produced by a company that is known for producing audio equipment that is cost effective. A careful evaluation of this model revealed the following information:


  • Color: Black
  • Size dimension is at 2.9 x 1 x 3.5 inches
  • It weighs two pounds or less than one kilogram
  • Made using CNC aluminum materials that are resistant to scratches
  • Manufactured using a semi-set tube design
  • Single-chip microcomputer and relay design
  • Circuit power: dual JRC5532DD
  • Two small 6J9 J-grade vacuum tubes
  • Power button and indicator
  • Volume control dial that can be turned
  • Circuit core parts contain two NJM5532D
  • Two LED lights that are color blue
  • The input interface is 3.5 millimeters stereo or headphone jack
  • Output power is from 13 milliWatts to 70 milliWatts (300 ohms to 32 ohms)
  • Its total harmonic distortion plus noise (THD + N) is 0.0015%
  • Sound-to-noise-ratio is at 80 decibels
  • Frequency response is from 20 Hertz to 20 kilohertz
  • Residual noise is at 0.02 millivolts
  • Consumption power is at 5.6 Watts
  • One adapter
  • Instruction manual


  • Ground noise, on-and-off, and relay sounds are absent
  • Small or portable
  • Lightweight
  • Good input signal
  • Scratch resistant
  • High level of drive current
  • The part of the tubes that has the highest temperature is placed in a safe area
  • Compatible with E180F, 6J9P, EF861, and 6688 replacement vacuum tubes
  • Sound produced is of high quality
  • Produces strong drive current
  • Controllable muted sound
  • Device warms up prior to sound transmission
  • Designed to protect the speakers of the connected device
  • Designed to protect connected headphones and user’s ears
  • Clear and visible warming-up, ready-to-be-used, and power indicators
  • Compatible with any types of sound-producing devices
  • Compatible with many types of headphones and stereos
  • Like the Fosi Audio P2, it’s great for use with turntables


  • Requires a USB DAC to connect it to electronic devices
  • Cannot be placed inside the pocket

Detailed Discussion

This small, lightweight, and portable vacuum tube headphone amplifier is designed to stand the test of time because of its scratch-resistant, aluminum-made internal and external body. It has two 6J9 J-grade tubes and NJM5532D circuit core parts that increase the product’s voltage and input signal levels.

It has a power indicator light that is easily recognizable and a power button that is easy to use.

The vacuum tubes of this headphone amplifier are equipped with LED lights that blink for approximately 35 seconds when the unit is at the warming-up stage. The blue color of the LED lights become stable once the unit is ready to be used.

It is also designed using a single-chip microcomputer and relay technology so that the muted sound can be controlled once the device is turned off or on.

Also, it has a headphone or stereo jack that has a standard-sized hole which makes it compatible with most headphones and stereos in the market. Although this product heats up when being used for long hours, the part of the tube that reaches the highest degree of heat is placed inside the product wherein the user will not be able to reach.

And in cases wherein the tubes burst or broken, they can be easily replaced since there are a lot of replacement vacuum tubes that are compatible with them.

A Helpful Comparison:

The Little Dot I+ 6JI X2 Tube standard Hybrid Headphone Tube Amplifier is a product that shares some common features with the SMSL T2 2X6J9. It is also designed with two vacuum tubes and a volume control dial that is easy to turn and adjust. Likewise, it also made of quality materials making it durable.

It is also lightweight and small that makes it portable but a little bulkier than the SMSL T2 2X6J9 headphone tube amp. Likewise, it also produces warm and solid sound but falls behind the SMSL T2 2X6J9 when it comes to signal levels. Additionally, unlike the SMSL T2 2X6J9 this product cannot be connected to a stereo.

Final Verdict:

The SMSL T2 2X6J9 Super Low Ground Noise Vacuum Tube Headphone Amplifier is a user-friendly and lightweight amplifier that is recommended for individuals who need a headphone amplifier that can be brought anywhere. With its small size, it can easily be placed inside a backpack or a spacious pouch bag.

Likewise, with it having a scratch-resistant body, owners no longer need to worry about covering them with protective waxes or any materials.

Apart from its construction, this product also stands out when it comes to reducing background noises to the point that even the typical buzzing sounds are absent. Likewise, the manufacturer made sure that the safety of the users is also taken into consideration by placing the tubes strategically.

However, the common problem with shattering tubes is still present but replacing it will not be a problem because of its compatibility with many tube models.

So, for music lovers who need an easy-to-use, manageable, safe, and durable headphone tube amplifier that produces quality and low- or no-background noise sound, the SMSL T2 2X6J9 is a great choice.



1 thought on “SMSL T2 Tube Headphone Amplifier: A 2023 Review”

  1. ¿Is possible to replace the tubes of the SMSL T2 tube amp with the Mullard CV 4010 or EF95, like the Little Dot I+?

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