The Gremlin tube headphone amp is a little monster with a ferocious bite. With 1250mW of output power, it has the muscle to drive most headphones that cross its path. It may be ugly, naked, and small, but don't judge a beast by its cover. For just $120, you're getting a Class A, fully-balanced tube amp with matched tubes—something unheard of at this price. It delivers sound that’s sumptuous and lush, with musical tonality and heart-melting mids. Once it gets its claws in you, you won't want it to let go.
Feeding the beast: Tubes + transistors
The Gremlin is a hybrid headphone amp that combines the precision of transistors with the warmth of vacuum tubes. While solid-state amps (which rely solely on transistors) deliver accuracy, they lack the soul of tubes. In the Gremlin, the vacuum tubes in the pre-amp stage flood your music with rich harmonics and a warmth that solid-state amps can’t touch.
Always hungry: the Gremlin's Class A appetite
The Gremlin is a predator that never rests. With a Class A design, it's always on the hunt, keeping the current flowing without pause. Other amps flip their transistors on and off to save energy and keep cool—efficient, sure, but prone to distortion that muddles the sound. Not this beast. Its relentless operation means every note is delivered with the raw purity and ferocious detail that only Class A amplification can provide.
A poised predator: a fully-balanced amplifier
With a fully-balanced design from input to output, the Gremlin cancels out the kind of hums, buzzes, and interference that can creep in with unbalanced systems. This means you get a cleaner sound—especially important if you're using sensitive headphones or high-end equipment that picks up every little detail. The Gremlin gives you the best of both worlds: the warm, rich tones of tube amplification with the minimal interference of balanced design.
Matched Ray Tubes: the Gremlin’s natural weapon
The Gremlin comes armed with a matched pair of CORE 12AU7 from Ray Tubes to give you that signature tube warmth right out of the box. When tubes are matched, it means they’ve been carefully tested to ensure they work together as a pair, delivering the same output and frequency response. This results in better soundstage, clarity, and stereo imaging—key elements for an hi-fi listening experience. And if you're looking for even more depth and detail, we recommend upgrading to a pair of matched Ray Tubes SELECT 12AU7 tubes. Choose the 12AU7 SELECT and you'll get both sets—letting you tube roll and discover the extent of the Gremlin’s power.
Embark on the quest for your perfect sound
The Gremlin Amp is made for audio lovers who want to explore the world of sound. It works with any 12AU7 or 6922 tubes, new or old, allowing you to easily swap and try new types. Whether you prefer a lush or linear sound, the Gremlin lets you customize your audio setup whenever you want a change.
STACK THE PARTY
Add the Stacker to your order if you plan on using the Merlin DAC with the Gremlin amp. This translucent acrylic platform lets you stack the two together like a proper adventuring party. It's precision-cut to cradle the Gremlin's lower acrylic plate and keep it snugly perched without adhesive or screws. Our very own Sean Flynn designed the stacker, and our buddies at Salad made it a reality. We’ve priced it to be a no-profit product—the price you pay simply covers our costs. But we’d like to keep the DIY community ethos going, so we’re working with Salad to make it an open-source download on GitHub. Print it, tweak it, remix. If you come up with something great, send it our way at communityfeedback@apos.audio so we can show it off.
Product Highlights
Class A headphone amp with 1250mW of output power at 32Ω
Fully-balanced architecture with 4-pin XLR and 4.4mm inputs and outputs
Low noise floor: 100dB SN
Excellent channel separation: 104dB at 1kHz
Wide headphone compatibility: suitable for headphones with an impedance range of 8-600Ω.
Comes with matched pair of Ray Tubes CORE 12AU7
Specs
Uses 12AU7 or 6922 tubes
Three-level tube with Class A buffer output
Inputs: XLR, 4.4mm
Outputs: 4-pin XLR balanced headphone jack, 4.4mm balanced headphone jack
Uses a DC 18-24V power supply
Output power: 1250mW @ 32Ω
Frequency response: 20Hz-50KHz (+/-0.5dB)
Signal to noise ratio: 110dB
Minimum distortion: 0.01% (1KHz)
Separation degree: 104dB (1KHz)
Suitable headphones: 8-600Ω
Dimensions: 5" W, 3 1/4" D, 2 1/2" H
An Apos 𝒙 product
Apos 𝒙 is the next generation of grassroots products. It bridges designers, manufacturers, and the community to turn ideas and feedback into unique creations. By involving the community at every stage and supporting designers, Apos 𝒙 ensures that products reflect the desires and creativity of their users. Participate today.
Apos 𝒙 credits
Community Participants
These affiliates, influencers, and audiophiles gave us early feedback that helped refine the final version of the product. If you’d like to participate in future launches, fill out our form.
"For the price, it's absolutely amazing. It performs well above its price point, is wonderfully upgradeable, and suitable for most headphones on the market at any performance level." -Passion for Sound
"Really enjoyable. A steal." -Joshua Valour
"Great detail, soundstage, and channel separation. Does a great job at keeping the treble in check. Has great sounding-midrange and musical bass." -Forever Analog
"An absolute beast. I love what Apos is doing here. It's a banger." -Gadgetry Tech
"The Gremlin is a shockingly good balanced amplifier. It sounds really, really good." -Joshua Valour
"Just shut up and take our money, Apos. Grab the Gremlin and thank me later." -Passion for Sound
"TLDR: Just buy it! I highly recommend it. This thing is amazing." -TylerElectric
"This is very good. This thing is super cool. I think it'll be the door-opening component to the tube universe for a lot of people." -United States of Analog
"This amp with SELECT tubes can outperform the TOPPING L70 ($350) and the TOPPING A70 PRO ($500). A really great little amp." iiWi Reviews
"It's good and it's fun and it looks cool. Apos had fun with this. The owner manual's is hilarious. You gotta read it. It's a nice, solid amp to use all around." -Wave Theory
"The sound is fantastic." -Mr Ayrit
"An affordable masterpiece. One of the best buys currently available. Sound quality, musicality, driving power--everything is great." -Tharbamar
"A W for sure. It's silly to me that you can get all of this for this price. A banger." -Badseed Tech
"I will say straight up that Apos have done a bang-up job designing the Apos Gremlin. It tickles both my inner engineer and the sound lover. Discrete, balanced, tubes, Class A, and at that price? You have to be kidding me. And it sounds both good and interesting! I can tell that true enthusiasts have been at work here, so this is an easy “Headfonia Recommended”!" -Headfonia
Apos x Community Gremlin Tube AmpSale price$120.00 USD
The Apos x Community Gremlin Tube Amp offers a unique blend of tube warmth and solid-state precision, delivering a lush and musical soundstage. Valued for its affordability, the amp is praised for its minimalistic design and exceptional sound quality. Customers highlight its impressive output power and balanced architecture, making it a standout choice for audiophiles.
"very lush mids and nice sparkle and air in the treble with great soundstage and layering." — Shaun k.
"In any case the sound is clear, neat and with a good soundstage." — Cesare B.
"The sound stage is huge and instruments along with the male and female vocals sound very natural." — Mitch U.
Reviews
Don’t Think, Just Buy the Gremlin!
"I was very surprised at the sound of this little amp. I picked up a well matched pair of NOS 1957 RCA 12AU7 Black Long Plates and the sound is incredible! The sound is warmer with more low end bass, better dynamics and a much wider soundstage than the stock tubes. The value is unreal - Fully balanced, Class A, Discrete hybrid tube amp with plenty of power. If I paid 4-5 times this price, I’d still be overjoyed with this purchase. Great way to get started tube rolling. I’m new to tubes, but a big fan so far. IMO, tubes have a much bigger impact on the sound than a DAC does."
— Glen H. (5/5)
Best Amp I own
"Took forever for me to find a service tech to help with my tubes but she was worth it. Buy the way I have 8 other headphone amps and the Gremlin is the first to make me go wow that sounds different and more importantly noticeably better."
— HippiePenguin (5/5)
Gremlin and Druid Make a Great Combo
"Paired the Gremlin with a Druid and a pair of Apos Flow balanced cables. Works well with my HiFiman 400is. Sound is transparent; yet more full and lush than a solid state amp such as the Fiio K11 R2R which I use with an old Oppo BDP-83 Special Edition. The Druid and Gremlin are being run off my 2019 iMac. I use Decibel or an older Audirvana for software. The DAC was immediately recognized when plugged in."
— John K. (5/5)
Great power and completely silent. Drives my headp
"I changed my old hybrid amp for the Apos x Gremlin because I wanted more power and better precision than my old portable DAc and ATH-M50xBT setup could provide. It works perfectly stacked with the Druid DAC. I use it with my Audio-Technica ATH-R70x, and I also added the Apos pads (the ones from the ATH-R70x Refine). It's my main hub for Spotify, movies, and gaming. Right now, I’m using the basic Ray Tubes 12AU7 Core, and it sounds excellent with everything. My playlist goes from classical, jazz, and lounge to electronics, synthwave, ambient, pop, rock, and heavy metal. For chill tracks, the sound is natural and spacious, and movies or games feel incredibly immersive. What really blew me away is the weight and punch of the sound—especially in metal and electronic music where the bass is fast and tight. I didn't expect such a full-bodied sound without touching any EQ. With my old setup, I was constantly tweaking software correctors, but with the Gremlin, I completely forgot about EQ. The amp is also completely silent with zero background hiss. I have a pair of Ray Tubes 12AU7 Select in a box to swap later, but even stock, it's a beast. I can't go back to my old gear, so I'm selling it. Highly recommended!"
— AaA (5/5)
Apos Gremlin tube Amp
"Awesome device, still burning in the tube. . . . Sounds amazing. . . Highly recommended. . . In time I will look to upgrade the tubed. . . But sock standard is next level. . . Buy, don't hesitate. . . THANK ME LATER."
— Michael T. (5/5)
"Fast and quick delivery and as far as I can tell, it is what it says it is awesome. I’d order from them again."
— Carol (5/5)
Nice HPA. . .
"It sounds really nice, with the right tubes. . . I'm using Mass Drop Sennheiser HD 6XX HP's, and I just wasn't getting the sound I wanted with the stock tubes, I let the amp warm up, I let the tubes burn-in/settle, and it still wasn't there for me I upgraded to EH 12AU7 EH Gold Pin, sounded much better, same deal, warmup, burn-in/settle, but just not "there". . . So once again, I upgraded, to the 5814A / 12AU7 JAN Philips, sounded nice, really nice, and this is where I'm at today, 5814A / 12AU7 JAN Philips, matched, tested for low noise & microphonics, high gain matched, balanced triodes. . . Every time I listen, it gets just a little bit better, tubes have about 60hrs on them, they're burned-in and settled. . ."
— Brian S. (4/5)
An exceptional amp & listening experience!
"If you’re reading reviews of the Gremlin and considering buying one, don’t hesitate, just get one you won't regret it! This amp is exceptional. I already own a Schiit Audio Jotunheim 3 and was perfectly happy with it, but curiosity pushed me to try a 'tube' headphone amp, and I’m so glad I did. The first time I plugged my HD660S2s into the Gremlin I couldn’t stop smiling; compared to the Jotunheim, the Gremlin's warm & rich sound presentation makes listening to music, and gaming audio, an absolute joy. I’m considering selling the Jotunheim now because it isn’t getting any use. To my ears, the Gremlin is that much better and is consistently a pleasure to listen to. It's also been fun to do some experimentation with tubes and how they change the sound character of the Gremlin. I bought the Ray Select tubes as an upgrade when I bought the Gremlin from Apos, but after some A/B testing I ended up preferring the Core stock tubes, which sound (to my ears) smoother and less fatiguing over long listening sessions than the Ray Select tubes. Weirdly, despite great reviews, I had the same experience a pair of Genalex Gold Pin 6922 / E88EC tubes. I preferred the smoother and easier to listen to stock Core Ray tubes in the Gremlin versus the Genalex tubes, but enjoyed experiencing the weight and punch that the Genelex tubes gave to bass when listening with those socketed into the Gremlin. Well done Apos team - you've created something truly special and accessible with this product!"
— Simon (5/5)
"Very happy with this, I was never a audiophile until I got intrested into getting better quality headphones, ever since I got them I've been venturing for a better sound. And this here definitely enhances my love for sound!"
— Corey (5/5)
2 Words - Blown Away. 11/10
"The Druid/Gremlin combo blew me away immediately. after letting the tubes sit for 6 hours as instructed to burn in, I put on my test playlist and after 1 minute was blown away completely and started writing an email to the team at Apos (who have had 11/10 customer support and I have probably a 60 long email chain dealing with questions and some minor troubleshooting or if other devices will work with it or op amps I wanted to swap in etc. ) about how grateful I am for this product (with the Gremlin). It genuinely almost brought tears to my eyes with how amazing the music was (HD 800s - I'm sure the fact that these cans are THE headphones for tubes made a difference here but still, I normally lean bright and more clinical and yet an r2r + tube pairing only made me love my 800s more. after about a month with it I swapped in some Sparkos ss3602's replacing the 2x BAL op amps and a Burson V5i-D for the SE 3. 5MM>RCA connection that is currently going to my Fosi ZH3 ( that just like the druid has swappable op amps, and it also has a Burson V5i-D set in it (2x), so 3x Burson V5i-D's in total for the Druid>ZH3 chain and 2x ss3602's from Sparkos for the 2x XLR 3pin BAL OUT to the Gremlin tube. absolutely RIDICULOUS COMBO. . . . I have no words for how beautiful it sounds. at this price point this is borderline criminal with how good this iem the swappable rollable op amps and balanced connections make it incredible. nothing bad to say. I suppose if you don't like the DIY open aesthetic it might not be for you but man I love it- but most importantly the sound is fabulous. Even going to my ZH3 it makes that 3-in-1 device (when used as an amp in this case, just so nice with that r2r-ness smoothing things out when you don't want full on tube sound but also not regular clinical-y solid state delta sigma sound. just amazing, the customer support, op amp swap feature, and price to performance make this an 11/10 product for me."
Would the Russian 6N1P-EV tube work as a substitute?
Hello. The 6N1P-EV would not work as a substitute for the stock tubes.
Will the Amperex 7308 Gold Pins work with the Apos x Community Gremlin?
Hello. Yes, the Amperex 7308 Gold will work with the Gremlin as a 6922 variant.
In regards to power, what is the maximum current draw (in amps) through the DC port? This spec is not stated anywhere.
Hello. The actual power consumption is DC 24V/0.8A, with the minimum required power supply specification being 24V/2A. There is no limit to the maximum current; for example, 3A, 4A, 5A, 6A, etc., are all acceptable.
