3 Tube Headphone Amp Designs & Why We Love Them

Read Time: Approx. 12 min.

Auris Nirvana IV Tube Headphone Amplifier, Moon Audio Dragon Inspire IHA-1 Tube Headphone Amplifier, Cayin HA-6A Tube Headphone Amplifier, and Meze Audio Empyrean 2 Headphones grouped together

Enjoy Warmth and Musicality all wrapped up in a Nostalgic Design

Audiophile headphones deserve a quality headphone amplifier but how do you choose the BEST headphone amp when there are so many options? Tube amplifiers have been around since the early 1900s and are well-loved by audiophiles for their warm sound and nostalgic feel. We've selected three of our best-selling vacuum tube amplifiers to compare to each other — The Auris Audio Nirvana IV Headphone Amplifier, Moon Audio's very own Dragon Inspire IHA-1 Tube Headphone Amplifier, and the Cayin HA-6A Tube Headphone Amplifier.

Drew's Take logo

"Three Tube Amplifiers — Three different personalities. No doubt these are three of my favorite Tube Headphone Amplifiers at Moon Audio. The Dragon Inspire is its purest approach and has plenty of grace but that can be dramatically changed sonically with the roll of a tube. The Auris Nirvana IV is for feeling like you're at a Led Zeppelin show back in the 70s with just raw gritty power. And the Cayin HA-6A is a real gem and fabulous bang for the buck with the coolest option ever of a 4.4mm connection optimized for IEMs. Who would have thought? No winners and losers here, it's a tie-ball game. Pick your poison."


Each tube amplifier is unique in its own way but they all possess that distinctive warm glow that makes them just undeniably cool. Priced at $2,499, the Cayin HA-6A is a modern-looking tube amplifier with a hand-painted aluminum alloy finish, glossy and matte black accents, and a removable vacuum tube cage for protection. The VU meters on the front panel illuminate the same warm yellow glow as the tubes giving the HA-6A a nice pop of color. At almost a whopping 43 pounds it's the heaviest tube amplifier in this lineup but its sharp form factor compliments most audio setups.

The front panel features various headphone outputs, a power on/off button, a headphone output selector, VU meters, a source switch, and a volume knob. The outputs include a 1/4" output, 4.4mm balanced output, and 4-pin XLR balanced output. There's also an impedance switch with three gain modes and an operation mode switch which I go into more detail about further down in the features and technology section. On the back is a balanced stereo XLR input, a single-ended stereo RCA input, a tube selector switch for swapping power tubes, an external fuse for high voltage, and the AC power input.

Cayin HA-6A Tube Headphone Amplifier front panel display
Moon Audio Dragon Inspire IHA-1 Tube Headphone Amplifier

The Dragon Inspire IHA-1 is extra special to us because it's a Moon Audio exclusive. Designed and perfected by our Owner and Founder Drew Baird, P.E., in partnership with Cary Audio's Founder Dennis Had, the Dragon Inspire is vacuum tube amplification in its purest form. Priced at $2,195 it's the smallest of all three tube amplifiers and the lightest at 15 pounds. With a metallic copper finish and black accents, the Dragon Inspire is both retro and modern looking. The front panel features a 100k dual-stepped attenuator volume control, analog RCA input selector switch, 1/4" headphone output, 4-pin XLR headphone out, power switch, and power indicator. On the back panel is a power port, fuse, output switch, pre-amplified left and right outputs, and two pairs of aux ports.

At $5,799 the Auris Nirvana IV is relatively the same size as the Cayin HA-6A but it's almost 50% lighter at roughly 25 pounds. For it being a large headphone amplifier it has a distinctive form factor with a prominent front panel, glass protection plate, and rounded edges. Two transformers sit atop the amp with an impedance knob, and an external power supply unit also comes with the Nirvana IV that attaches via a high-quality 1m cord. Having the power supply in its own external chassis is what makes the Nirvana IV so much lighter than the Cayin HA-6A and it also reduces interference from the power supply circuit. 

The entire unit has a matte black finish with silver accents. On the front panel is a power switch, input selection knob, balanced 4-pin XLR output, VU meters, 1/4" stereo headphone output, gain switch, and volume knob. On the back panel you'll find two pairs of RCA inputs with a pair of 3-pin XLR power inputs, a pre-out RCA output, and PSU ports for the external power supply unit.

Auris Audio Nirvana IV Tube Headphone Amplifier with Meze Audio Empyrean II Headphones


So how do these three tube amplifiers stack up against one another in the sound department? While all three possess that signature warmth, they've all got a distinctive sound. The Dragon Inspire IHA-1 is warm and lush sounding with great musicality when using the NOS RCA Tubes — More on this later. The Nirvana IV has some nice warmth to it with incredible dynamics and lots of energy. And the Cayin HA-6A sits right in the middle with just enough warmth to make it a great choice for someone who wants a neutral, yet musical sound.

I decided to A/B test each tube amplifier with the Meze Audio Empyrean II Headphones paired with a Black Dragon Premium Headphone Cable with a 4-pin XLR connector and the Aurender A200 Music Streamer as my source. From the moment I plugged the Empyrean II headphones into the Nirvana IV everything just clicked. I listened to 'From Eden' by Hozier and 'The Summoning' by Sleep Token on the headphone amps to identify the nuances of each unit. 'From Eden' is an alternative/indie song with soulful, gospel-like vocals that lend to a harmonious and expressive sound. The Nirvana IV was incredibly musical and dynamic, so much so that I was taken aback by the sound quality. I've listened to the Empyrean II headphones with many pieces of HiFi audio gear and the Nirvana IV made them sing like nothing I'd heard before. I was immersed in a sound that was rich and luscious with great layering and a wide soundstage.

The Summoning by Sleep Token is on the opposite end of the genre spectrum as a heavy metal song with a rock n' roll feel. You're immediately thrown right into the madness with a brigade of electric guitars and drums. The song takes you on a journey from metal riffs to choruses with passionate R&B-style vocals. Of all three amplifiers, the Nirvana IV handled the energy of this song the best. Sound-wise, the Nirvana IV is going to appeal to the warm and musical listener who enjoys a dynamic sound full of energy with a tight, punchy bass.

Auris Nirvana IV, Dragon Inspire IHA-1, Cayin HA-6A, tube amplifiers paired with the Meze Audio Empyrean II Headphones and the Aurender A200 Music Streamer on a shelf setup

The Dragon Inspire IHA-1 is wonderfully warm and smooth. Every song I listened to had great dynamics and the right amount of energy that never overshadowed the details. The soundstage was intimate but not crowded - I felt immersed in the music like I was a part of the band and not someone sitting in the crowd. The listening experience I got from the Dragon Inspire was very similar to the Nirvana IV - Musical, warm, and lush.

I kept going back to artists like Adele, Hozier, and Rainbow Kitten Surprise who deliver rich, emotive vocals. I'm a warm and musical listener through and through and the Dragon Inspire’s sound was right up my alley. There's not a single song that Adele produces that doesn't have her heart smeared across the track. Her vocals are full of so much emotion and passion that there wasn't a single moment listening to the Dragon Inspire that I truly didn't enjoy.

The Cayin HA-6A is perfect for someone who wants a more natural reproduction of their music. It's got a neutral-warm sound signature and two operation modes that you can switch between to change the tonality of the amp's sound. Triode mode is ideal for vocals and strings with a smooth, lush, harmonious sound. Ultra-Linear mode has improved power and extension delivering you a clean, energetic, authoritative, and transparent sound. It's ideal for music that requires a lot of punch, dynamics, and control.

I found myself enjoying the ultra-linear mode for high-energy genres like Hip-Hop, EDM, and Metal. It had more immediacy and sounded sharper. Triode mode was great for soft rock, Jazz, and Soul. For example, Anthony Kiedis's vocals in the Red Hot Chili Pepper's 'Scar Tissue' felt very mellow and lush in Triode mode. The song has a natural twang to it and at the end of each verse Kiedis likes to drag out that last syllable. Think of Triode mode as a taffy-pulling machine — lengthening vocals and sounds just ever so slightly to create this smooth sound that slowly fades.

All of these tube amplifiers complement a range of genres like Pop, Country, Alternative/Indie, Acoustics, and Jazz but the Nirvana IV is going to handle high-energy genres like EDM and Metal the best. The Dragon Inspire is going to appeal to the warm and musical listener who enjoys an immersive listening experience and gravitates toward lush sounds, but with tube rolling you can drastically change the sound of this little amp — More on this shortly. The Cayin HA-6A is the sweet spot in a way — It's got the warmth of a tube amplifier but just enough neutrality that you can also enjoy some highly-detailed tracks. So if you find yourself bouncing between dynamic, punchy tracks and smooth, lush sounds then the Cayin HA-6A will give you the best of both worlds.

Hozier album cover

From Eden

by Hozier


Sleep Token Take Me Back to Eden Album Cover

The Summoning

by Sleep Token

(Take Me Back To Eden)

Adele 25 Album Cover

I Miss You

by Adele


Sabrina Carpenter Emails I Can't Send Album Cover


by Sabrina Carpenter

(Emails I Can't Send)

Technology & Features

Now let's get into the nitty and gritty of these tube amplifiers — The technology and features. One of, if not the best features of tube amps over solid-state amps is tube rolling, which is the ability to swap out the tubes on the top of each unit. Each tube has its own coloration that impacts the overall sound, so by changing the vacuum tubes, you can alter the tonality and fine-tune your listening experience based on personal preferences. Pretty neat right? The options are virtually endless and it not only extends the lifetime of your amplifier but it also allows the unit to grow with you as your tastes change.

For instance, the Dragon Inspire IHA-1 features a pair of 6SN7 stock tubes and a 5Y3 rectifier tube that lends a lush, warm, and liquid sound but if that's not really complementing your favorite genre then no biggie, just swap them out! We recommend swapping out the rectifier tubes with a direct heater-type tube like the 5Y3, 5U4, 274B, or NOS. The output tubes can be swapped out with a 6SN7 variant tube.

The Cayin HA-6A comes with one set of Electro-Harmonics EL-34 tubes, a pair of JJ 12AU7/ECC82 tubes, and two RCA 17AX4GT tubes. The Nirvana IV also features a pair of EL34 tubes which are known for deep and tight bass, sweet midrange, and extended, detailed highs. Additionally, the Nirvana IV has an ECC82 drive tube that's known for being a low-noise tube.

Close up shot of the vacuum tubes on the Moon Audio Dragon Inspire IHA-1 Tube Headphone Amplifier

Featured: Dragon Inspire IHA-1 Vacuum Tubes

Featured: Dragon Inspire IHA-1 inside circuit

When it came to the circuit design of the Dragon Inspire IHA-1 Dennis Had knew that simplicity was key. The signal comes into the RCA, travels to the input transformer to clean up the signal, then goes to the volume, travels through each tube and the output transformer, and finally exits through the headphone jack. The result is a clean, short signal path.

While it has the lowest power output of 1.5W, and that's 0.1W lower than the Cayin HA-6A, the Dragon Inspire is going to be the most flexible amp in terms of the wide range of headphones you can pair with it. Thanks to the purest approach of the circuit design, you can greatly change the tonality of this amp with the change of a 6SN7 tube. Make sure to see the Dragon Inspire webpage to read more on swapping tubes. The Nirvana IV and Inspire can double as a preamp for your amplifier and speakers, but the Cayin HA-6A is truly a dedicated headphone amplifier.

The Nirvana IV is the most powerful amp with 6.5W of pure class A power per channel and it's the only one in the lineup that can easily drive the notoriously powerful HiFiMan SUSVARA open-back planar magnetic headphones. It's going to produce a lot more punch and authority to the sound than the Dragon Inspire IHA-1 and Cayin HA-6A. So if you're someone like me who enjoys Hip-Hop and EDM then the Nirvana IV is going to deliver you that great bass and attack.

However, the HA-6A does have the most connection options with a very special 4.4mm balanced headphone output that's less powerful than the four-pin XLR output. What makes it so special? The HA-6A is the only amp in this lineup that can effectively drive IEMs and that's all thanks to the low power of the 4.4mm output. When you pair a highly sensitive IEM with a tube amp more often than not you'll get background hiss — That's not to say you can't use IEMs with tube amps because you can, but in the case of the HA-6A they're counteracting that background hiss by reducing the power.

The HA-6A and Nirvana IV both have impedance switches with multiple gain modes. The HA-6A has three gain modes: 'Low' for headphones with an impedance between 8 and 64 ohms, 'medium' for 65 to 250 ohms impedance headphones, and 'high' for 251 to 600 ohms impedance headphones. The Nirvana IV takes it up a notch with five gain modes that drive headphones from 32 ohms to 300 and 600 ohms. An impedance switch wasn't needed for the Dragon Inspire as it's pretty versatile and works well with all impedances, even driving those pesky planar magnetic headphones.

The Dragon Inspire has a unique option compared to the other amplifiers. Not only is it a transformer-coupled output, but it also utilizes high-end Lundahl input transformers that strip off any incoming noise from your sources. It also boosts the gain and adds some detail and resolution to the incoming signal.

Each tube amplifier has its own collection of features and technology — If you've got a wide range of headphones that you like to cycle through then look no further than the Dragon Inspire IHA-1 to drive them all. Or maybe the low power of the 4.4mm balanced output on the Cayin HA-6A is perfect for your favorite pair of IEMs. With five gain modes, the Auris Nirvana IV is versatile and powerful enough to handle anything you throw at it. Whatever the case may be, you can't go wrong with any of these tube amplifiers — They've all got a great sound and a plethora of inputs and outputs making it easy to integrate any one of them into your existing home audio setup.

Dragon Audio Cables

[Silver Dragon Interconnect Cable, Black Dragon Premium Cable for Meze Headphones]

Let's talk cables because your new tube amplifier setup will need some. At Moon Audio our Dragon Audio Cables are handcrafted daily in our Cary, NC headquarters with the highest standards and made to order according to your specific needs. We'll create a custom cable for you using the highest quality UP-OCC silver or copper conductors that can be manufactured. When you're spending upward of $3,000 on a new piece of gear I imagine the last thing on your mind is all the accessories you've got to buy to go with it. Well, sometimes manufacturers have the same thought process and they don't prioritize the craftsmanship of the audio cables they include. Stock cables are, well stock cables, and having a high-quality cable makes a difference when you want the best possible performance from your gear. I mean have you ever seen Ferrari wheels on a Toyota? Probably not. Well if you're buying the Ferrari of tube amps we want you to have those matching wheels!

So for these three tube amplifiers, our Silver Dragon Interconnect Cable is going to be the perfect link between your devices. This is how we connected our source device the Aurender A200 to all three amps. The Silver Dragon Interconnect is built for zero interference with a braided geometry and high-quality shielding so there's nothing between you and your music. The UP-OCC pure Silver conductors add detail and resolution unveiling the music, allowing you to enjoy it with breathtaking clarity. The shielding will also add more durability to the cable for runs on a floor. Our Silver Dragon Interconnect Cable is timeless. It was the first ever Dragon Audio Cable produced and since then it's been a foundational piece in so many high-end audio setups.

silver dragon interconnect cable with the hi-fi+ editor's choice 2020 award plaque

Since I'm a warm and musical listener I opted to pair the Meze Empyrean II Headphones with our Black Dragon Premium Cable. Each of our Dragon Audio Cables has its own sound signature and the Black Dragon adds bottom-end weight to your headphones with great musicality. If that sounds like something you'd enjoy then the Black Dragon is a great choice, but it's all up to preference so you can't go wrong with any of our Dragon Audio cables. If you want more detail then opt for the Silver Dragon Premium, or if you want the most neutral sound without any coloration, give our Blue Dragon Premium Cable a try. Our Premium headphone cable line offers the same quality construction as our standard Dragon cables, but with extras like Premium Mundorf solder and premium rhodium-plated Furutech connectors that look and feel great while you listen.

I used a Dragon Premium Cable with a 4-pin balanced XLR connector but you can customize the cable length and connector options to fit your setup. We're flexible and we love to offer our customers the ability to customize their cables — So if you're not sure what connector you need or which dragon sound signature suits you best, we're always here to help!

Generally, stock audio cables are manufactured with subpar materials, metals with impurities, poor geometries, and an overabundance of layers to make them look and feel like a fire hose. Inconsistency and lack of quality control in stock cables can lead to poor sound quality and a veiled sound vs. what the musician intended for you to hear and feel from the music. Dragon Audio Cables are handcrafted with the highest standards and made to order according to your specific needs. At Moon Audio, we create a custom cable for you using the highest quality UP-OCC silver or copper conductors that can be manufactured. UP-OCC metals are void of impurities and are optimized for signal transfer and sound quality. We have one of the largest collections of audio and headphone connection options available online and we create limitless audio cable options depending on your specific gear and needs.

Why Dragon Cables?
You’ve heard the saying that a chain is only as strong as its weakest link, right? Well, the same applies to your brand new audiophile-grade headphone or other audio components. The weakest link, in this case, is your stock audio cable or the cheap interconnects the manufacturer threw in the box just to get you up and running. Why is the audio cable always an afterthought, when it’s just as important as the rest of your system? At Moon Audio, we use the purest and best raw materials in our cables to unveil your music. We believe that materials matter and your audio cables should have the same care and craftsmanship that manufacturers put into their audio components and headphones. Audio cables are ultimately the connection to your music. The fact remains that cabling is often considered the last priority to that of the main product and a means to cut down the overall production costs. It’s as simple as that. Dragon Cables elevate every note - as if you were hearing your favorite music for the very time. 

Experience the Warmth of a Tube Headphone Amplifier

When it comes to the best tube amplifiers it's hard to beat the Auris Nirvana IV, Dragon Inspire IHA-1, and Cayin HA-6A. Auris has made a name for itself in the amplifier market and the Nirvana IV is a great example of that. You get a robust, dynamic, and expressive sound from an incredibly powerful amplifier that's great for the most power-hungry headphones. If you're looking for the most natural reproduction of your music then look no further than the Cayin HA-6A. You get that signature tube amp warmth and a pleasantly smooth sound. It's full of features like two operation modes allowing you to alter the sound signature and it's the only tube amp in the lineup that's specifically built for your highly sensitive IEMs. And you just can't go wrong with Moon Audio's very own Dragon Inspire IHA-1. It'll complement every headphone in your collection, has the perfect amount of warmth, and its compact size is ideal for a desktop amp setup. It's Moon Audio's best-selling headphone amplifier for a reason. 

Whether you like Jazz, Pop, Country, Rock n' Roll, or R&B, you won't be disappointed with any song you listen to on these amps. You'll get a rich, harmonious sound from the Dragon Inspire IHA-1 and the Nirvana IV will handle those high-energy genres like EDM and Metal. The Cayin HA-6A is built for vocals and it stands out as a great option for the versatile listener. If you're in the market for a new tube amp with exceptional build quality, functionality, and great sound, check out one of these units!

Cayin HA-6A Vacuum Tubes
Auris Nirvana IV Vacuum Tubes
Dragon Inspire Vacuum Tubes

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Auris Nirvana IV Headphone Amplifier

Tubes: 1x ECC82, 2x EL34

Amplifier Configuration: Single Ended

Input Sensitivity: 1.4V

Power Output: Max

Output Impedance: 32 Ohm/ 80 Ohm/ 150 Ohm/ 300 Ohm & 600 Ohm

Analog Inputs: 3x Line

Analog Output: 1x Line

Dimensions (WxLxH): 312 x 322 x 220mm/ 12.28" x 13.07" x 8.66"

Weight: 11.4kg/ 25.13 lbs

Power Supply Dimensions (WxLxH) mm: 144 x 204 x 74

Power Supply Weight (kg): 3

Dragon Inspire IHA-1 Tube Headphone Amplifier

Frequency Response: 12Hz to 32kHz + - 0 dB

Power Output: Into 40 ohms 1.7 watts less than 1% THD 2nd harmonic

Amplifier Gain: 18 dB

Noise Floor: -87 dB

Outputs: Dual 1/4" Headphone Pro-Type, 4-pin XLR Pro-Type

Preamp Output: Switchable line level dual channel line (optional)

AC Voltage: 120 or 240 VAC 50/60 Hz

Output Power: Tubes X 2 6SN7 dual triodes

Rectifier Circuit: Vacuum tube rectification 5Y3

Chassis Material: .090 aluminum

Powder Coat: Copper/Clear Coat

Dimensions: 10" x 8" x 6" high with tubes installed

Weight: 15 lbs

Cayin HA-6A Tube Headphone Amplifier

Input Connector: XLR, RCA

Tube Used: JJ 12AU7/ ECC82 x2, Electro-Harmonix EL34EH x2, RCA 17AX4GT x2

Dimensions: 360mm x 322mm x 197mm

Net Weight: 19.5kg

Fuse: US Voltage 100V-120V: T2AL25OV

Power Consumption: 140W

Working Condition: 0℃~40℃; moisture: 20%-80%

Storage Condition: -20℃ ~70℃; moisture: 20%-80%

Rated Output:


Single Ended

TR: 800mW+800mW(L); 1600mW+1600mW (M); 2500mW+2500mW (H) UL:1200mW+1200mW(L); 2200mW+2200mW (M); 3600mW+3600mW (H)


TR:1200mW+1200mW(L); 2000mW+2000mW (M); 3200mW+3200mW (H) UL:1900mW+1900mW(L); 3000mW+3000mW (M); 4500mW+4500mW (H)


Single Ended

TR:750mW+750mW(L); 1400mW+1400mW(M); 2200mW+2200mW(H)UL:1000mW+1000mW(L); 2000mW+2000mW(M); 3300mW+3300mW(H)


TR:1000mW+1000mW(L); 1800mW+1800mW(M); 2900mW+2900mW(H)UL:1600mW+1600mW(L); 2800mW+2800mW(M); 4200mW+4200mW(H)