---
product_id: 633189349
title: "Douk Audio U3 Headphone Amps, Mini Hi-Fi Amplifier for Home Desktop PC 6.35mm / 3.5mm Headsets, Class A, RCA Input, DC 5V"
brand: "douk audio"
price: "¥12407"
currency: JPY
in_stock: true
reviews_count: 5
category: "Douk Audio"
url: https://www.desertcart.jp/products/633189349-douk-audio-u3-headphone-amps-mini-hi-fi-amplifier-home
store_origin: JP
region: Japan
---

# Drives 18-600Ω headphones effortlessly ≥1300mW output power @32Ω Wide 5-20V input voltage Douk Audio U3 Headphone Amps, Mini Hi-Fi Amplifier for Home Desktop PC 6.35mm / 3.5mm Headsets, Class A, RCA Input, DC 5V

**Brand:** douk audio
**Price:** ¥12407
**Availability:** ✅ In Stock

## Summary

> 🎶 Unlock studio-quality sound in a pocket-sized powerhouse!

## Quick Answers

- **What is this?** Douk Audio U3 Headphone Amps, Mini Hi-Fi Amplifier for Home Desktop PC 6.35mm / 3.5mm Headsets, Class A, RCA Input, DC 5V by douk audio
- **How much does it cost?** ¥12407 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.jp](https://www.desertcart.jp/products/633189349-douk-audio-u3-headphone-amps-mini-hi-fi-amplifier-home)

## Best For

- douk audio enthusiasts

## Why This Product

- Trusted douk audio brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Compact Powerhouse Design:** Miniature footprint (67x93x30mm) packs big sound, driving most headphones with exceptional clarity and dynamic range.
- • **Plug & Play Op-Amp Upgradeability:** Customize your sound signature easily with a pluggable op-amp socket—perfect for DIY audiophiles craving sonic personalization.
- • **Robust Build & Responsive Support:** Solid metal chassis with rave reviews for durability and customer service—buy now before the price climbs!
- • **Crystal-Clear Soundstage & Imaging:** Reveals intricate instrument details and precise spatial placement, lifting the veil on your favorite orchestral and vocal tracks.
- • **Audiophile-Grade Class A Amplification:** Experience ultra-low distortion and warm, detailed sound with a 1300mA large current output transistor.

## Overview

The Douk Audio U3 is a mini Class A headphone amplifier designed for home and desktop use, featuring a wide 5-20V input range, ≥1300mW output power at 32Ω, and compatibility with headphones from 18 to 600Ω impedance. It boasts a pluggable op-amp socket for sound customization, excellent signal-to-noise ratio (≥110dB), and a compact, durable design. Ideal for audiophiles seeking warm, detailed, and dynamic sound with precise imaging, the U3 elevates your listening experience at an unbeatable price point.

## Description

Warm tips:Not inlcude power adapter, recommend to use original high-quality power adapter above 5W. For example: the current should be above 1A if use DC 5V while need above 0.5A if use DC 12V power adapter. Parameters: Audio input: stereo L/R RCA Audio output: 6.35mm headphone jack (with 6.35mm to 3.5mm adapter) Output power: ≥1300mW (32Ω) Matched headphone impedance: 18-600Ω Frequency response: 20-30KHz Signal to noise ratio: ≥110DB Max output amplitude voltage: 25V Input voltage: DC 5-20V Dimension(W*D*H): 67*93*30mm / 2.64*3.66*1.18in Net weight: 169g / 0.37lb Package weight: 210g / 0.68lb Packing List: 1*U3 Headphone Amplifier 1*USB to DC Cable 1*6.35mm to 3.5mm Headphone Adapter

Review: Occasionally, all or most of us at least, wind up purchasing an inexpensive audio device, expecting that it will perform far below expectations - yet our curiosity (based on having seen advertisements or word of mouth) have enticed us to complete the purchase. Such was the case for me when I happened to stumble upon this particular Douk Audio U3 mini head amp on desertcart - noticed the price - and wondered if it would even approach marginal status. And since I happened to have several budget level DAC's such as the Schiit Modi 3, the SMSL M100, and a few others, I thought, "Why not try out this budget head amp to see if it can hold up?" When it arrived I was not prepared to be impressed the way I was. To begin with, the U3 is built like a small tank, exceptionally well crafted with a logical, simple, and impressive front and rear panel layout. The craftsmanship of the U3 is more reminiscent of far more expensive products. Additionally, for those who understand and appreciate being able to make various modifications to electronic devices, the U3 has a pluggable op-amp socket design, which allows one to experiment with different sound signatures - with op-amps being a dime a dozen now-a-days (and desertcart has quite a few of them). Now it is important to note that this is a "Head Amp" only. If you have a DAC and want to connect it to a Head Amp which also has outputs on the rear of such a device to connect to speakers, etc., that will not be possible. The U3 has RCA inputs only (no outputs), so it will serve as a headphone amplifier only. And regarding the U3 being a great Head Amp - well, the best compliment I can give it is to remark, "The U3 truly gives good head...." Haaaaaaaaaaaaaa I first paired the U3 with the SMSL M100 - a simple, yet impressive entry level DAC. Now normally, I always allow audio gear to go through a period of burn-in for 24-48 hours (which I eventually did with the U3), but just for the heck of it, I began playing music through it immediately. Headphones used were the HiFiMan 400i 2020 version, Sivga 007, Philips SHP 9500, Status Audio CB-1, and the Brainwavz HM5. Music being used for evaluation were various large orchestral classical, big band jazz, Latin jazz, and other larger orchestral varieties. For evaluation purposes, It is always a good idea to listen to large orchestras that feature a wide variety of instrumentation. This gives you a good reference point how an audio component can relay orchestral timbres of each instrument. Even upon the first turn-on, I was immediately struck by the musicality of the U3 and the ability for it to further separate various instruments with the proper air or space around their locations. Previously, when I listened to headphones through the likes of the iFi ZenDAC, Soundavo HP-DAC1, Micca OriGen G2, Fiio K5 Pro, and FX-Audio DAC-X6 Mk II, they all displayed different sound signatures - with some models displaying a very bright sound signature, while others sounded bland, and some being very good for the money. With the U3, I was now hearing instruments that previously were not noticeable because of the blending of the sound within the various orchestras. Small, quiet instruments such as cymbals, triangles, and others, were no longer buried behind the entire orchestra. Rather, they were lifted and open to where you could hear them distinctly. All the instruments playing - whether via a full symphony orchestra or a smaller, more intimate jazz group - had this openness to the performances. It was as if a substantial veil had been lifted between the listener and the music. Additionally, imaging (the placement of instruments on an imagery stage) was so precise that you could envision the musicians and exactly where they were located. Depth was also exemplary. However, do keep in mind that if you are running a horrible recording or a poor stream of lower quality music, the U3 will let you know. I should also add that this particular budget head amp is a great device to determine how good your headphones really are. Now do note that I've long discovered (and believed) that warming up/burning-in an audio device is essential because the sound signatures can change over time. When you first turn on the U3 and begin listening, it is very detailed (with the stock Op Amp that comes with it) and dynamic - and perhaps may sound bright to some. As time goes on - in my case being just 48 hours being left on all the time - the overall audio character warmed up - yet the sound was still detailed with plenty of dynamics. As an aside, you should leave your DAC's and/or Head Amps on all the time as they use negligible power. It's just not good to turn off and on (constantly) audio components, and you'll eventually discover that your audio components will have a longer shelf life in the process. Another positive aspect about the U3 is that musical instruments have an accurate timbre to their sounds - not colored at all. I kept mumbling to myself, "Is this thing really a thirty-something dollar head amp?" If ever there was a piece of audio gear that defied expectations (for the better), the U3 meets that scenario. Following my discovery of the U3's capabilities, I then wondered that if the U3 sounded superb with the likes of the entry level SMSL M100 or the Schitt Modi 3 DAC's, what would it do with far more expensive and higher end DAC units? In fact, in my opinion, I'd still call it a bargain if the U3 was priced at $100-$125 - it is that good. Like I said, it makes you now want to pair it with far better (more expensive) DAC's to evaluate the sound quality, which I can only imagine would be improved even more so. Look - I do quite a few blogs and reviews about various audio gear. This Douk U3 threw me for a loop - I found it that stunning, given its ridiculously low price. I strongly suggest picking one up before the price rises. I'm actually in the process of ordering a second one - mainly so I can change out op amps in one, while keeping the other with the stock op amp. At this price, it's a no-brainer. Given my previous experiences with evaluating high performing, yet very inexpensive audio items - which after a series of excellent reviews - were predictably followed by price increases by the vendor. I believe that once Douk sees the reviews on the U3, like anything else, they may very well raise the price. Now let's address the ability to easily remove and change out the Op Amps. This is something I had initially not considered doing with the U3, but since Douk specifically advertised this feature, that piqued my interest. So I purchased several Op Amps and tried them all. And yes, there were sound differences - some making the U3 sound brighter, some harsher, and some warmer. I found that upgraded Burson Op Amps - albeit a bit more expensive - did the best and noticeably elevated the sound performance of the U3. The Burson V5 version homogenized the sound, had a warmer upper register, yet still maintained excellent detail/definition, and had quite a bit of weight to the music. Also keep in mind (remembering about what I wrote above about allowing an audio device to be broken-in), when you switch Op Amps, as they warm up, their sound character will also change and usually for the better (meaning an increased warmth to the audio). So when you first insert an Op Amp in the U3, it may at first sound brighter, but don't let that dissuade you. Give it a few hours or up to 48 hours to be able to notice a discernible change in sound character. Be careful with op-amps though because if you insert it the wrong way (like backwards), you will immediately burn out/destroy the op-amp (not the unit). So before you do any op-amp rolling, PLEASE - be careful and know what you are doing. Given that, the op-amp that comes with the U3 is quite competent and musical sounding. Well, how about any negatives you may ask? Well, yes there is one (subjective) - and that is the front blue light which indicates on/off status of the U3, is rather large (and bright) when compared to the rest of the unit. It features an overly bright blue light which can light up a room at night (without exaggeration). When it's on, especially at night - and your sitting close to it such as by a desktop computer while listening to music - it can be extremely distracting because of its brightness. And when that light is "blue," somehow it becomes more pronounced. It would have been nice if Douk designed the light to be either red or green, which would have toned down the effect somewhat. So that's the only negative thing I can report really. I was so impressed with the U3 that I purchased a second one shortly after getting the first copy. Now when it comes to support - wow, are they good! After 4 months or so, one of my U3's developed a loud hum in the headphone jack. At first I thought it was the headphone I was using, but soon discovered that something happened with the U3. So here it was - June - and I contacted Douk via desertcart. They were quick to respond - didn't ask any questions - and sent me a new U3 in a jiffy manner. Now that's support to the maximum. So, based on its uncanny low price vs its ridiculously high performance ratio, I am enthusiastically rating the Douk Audio U3 mini head amp with 5 stars. It's just that good!!!!
Review: Awesome amplifier, easily a thousand dollar sound selling for 2 figures, the signal to noise ratio is also extraordinarily impressive when powered by my power bank which is a DC power supply.

## Features

- Adopting innovative circuit design, DC 5-20V wide input working voltage, the amplifier circuit can always work at a high voltage of 26V, and the background noise index is excellent. With wide frequency response extension, excellent transient response, excellent purity and transparency, and good dynamic range.
- Adopting original TI-NE5532 classical op amp and transistor expanding current circuit, using 1300mA large current output transistor working in class A status, with ultra-low distortion, and the sound is warm and delicate, full and mellow.
- Pluggable op amp socket design, convenient to upgrade different op amps and bring much DIY fun and playability for audiophiles. Smooth and mellow sound, suitable for listening to vocals or string music, classic or pop music, and even with unique charm when playing rock.
- Mini size with exquisite appearance and most cost-effective, brings big surprise for all audiophiles, easily to drive most headphones in the market, providing larger power, better sound field and details, very suitable for home/office desltop audio system use.
- With strong drive power, easily to drive most high-impedance headphones such as: HD580/HD600/HD650/K701/K702/Q701/DT880/T70/T90/SR225/SR325/RS1e

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B08C2MKBGN |
| Best Sellers Rank | #26,881 in Electronics ( See Top 100 in Electronics ) #70 in Home Audio Amplifiers |
| Item model number | XZ-U3 |
| Manufacturer | Douk Audio |
| Package Dimensions | 13.21 x 9.19 x 8.31 cm; 167.83 g |

## Product Details

- **Brand:** Douk Audio
- **Manufacturer:** Douk Audio
- **Maximum supply voltage:** 20 Volts (DC)
- **Minimum supply voltage:** 5 Volts (DC)
- **Mounting type:** Freestanding

## Images

![Douk Audio U3 Headphone Amps, Mini Hi-Fi Amplifier for Home Desktop PC 6.35mm / 3.5mm Headsets, Class A, RCA Input, DC 5V - Image 1](https://m.media-amazon.com/images/I/61Q-w-nktiL.jpg)

## Questions & Answers

**Q: What is the advantage or disadvantage of using a power supply voltage higher than the 5v you get through the usb to dc cable?**
A: The USB power plug included, when plugged into the PC directly just have an overwhelming hiss.  The hiss left when I used a 1A 5V USB charger, but the best sound came when I found an old large "wall-wart" 12V 1A with the same plug.  The jump from 5V to 12V added a lot of warmth and detail.  Get the linear supply wall-worts, not the switching kind (generally smaller in form-factor).  I also used ferrite snap-on cores on the audio from the pc, high quality shielded audio cables.  I'm most pleased with this unit when it's properly powered.

**Q: Is this a decent headphone amp for a turntable that has a built in pre amp?**
A: Signal source is irrelevant as long as it is a low impedance line level.

**Q: Can someone post a link to a good DC power adapter for this sold on Amazon?**
A: When I purchased this item recently from Amazon, I had a similar concern about the power supply, because I live in a 220V 50Hz electric supply zone. In my case, I received the amplifier with a charging cable having a standard (I think) plug on one end and a USB A plug on the other end. This end can be plugged into any phone charger with a USB A port. I found the amplifier works very well if this is also plugged in the USB port on the computer.

**Q: How do I pick another power supply for this? I’d like to replace it but don’t know how to figure out if something will work with this.**
A: I’m using a Radio Shack 12volt 1000ma power adapter. It comes with different tip sizes so I used one that fit and that had a positive center like shown printed on the back (near the receptacle) of the amp. The range required of the Douk is 5 volts to 20 volts so mine being 12 volts is good. In the reviews someone  commented that they had issues with using 5 volt chargers. That’s why I went with a little more power. 
Check your manual in case they made changes to this unit since the time bought it( earlier this year)

## Customer Reviews

### ⭐⭐⭐⭐⭐ Review
*by B***N on 28 February 2021*

Occasionally, all or most of us at least, wind up purchasing an inexpensive audio device, expecting that it will perform far below expectations - yet our curiosity (based on having seen advertisements or word of mouth) have enticed us to complete the purchase. Such was the case for me when I happened to stumble upon this particular Douk Audio U3 mini head amp on Amazon - noticed the price - and wondered if it would even approach marginal status. And since I happened to have several budget level DAC's such as the Schiit Modi 3, the SMSL M100, and a few others, I thought, "Why not try out this budget head amp to see if it can hold up?" When it arrived I was not prepared to be impressed the way I was. To begin with, the U3 is built like a small tank, exceptionally well crafted with a logical, simple, and impressive front and rear panel layout. The craftsmanship of the U3 is more reminiscent of far more expensive products. Additionally, for those who understand and appreciate being able to make various modifications to electronic devices, the U3 has a pluggable op-amp socket design, which allows one to experiment with different sound signatures - with op-amps being a dime a dozen now-a-days (and Amazon has quite a few of them). Now it is important to note that this is a "Head Amp" only. If you have a DAC and want to connect it to a Head Amp which also has outputs on the rear of such a device to connect to speakers, etc., that will not be possible. The U3 has RCA inputs only (no outputs), so it will serve as a headphone amplifier only. And regarding the U3 being a great Head Amp - well, the best compliment I can give it is to remark, "The U3 truly gives good head...." Haaaaaaaaaaaaaa I first paired the U3 with the SMSL M100 - a simple, yet impressive entry level DAC. Now normally, I always allow audio gear to go through a period of burn-in for 24-48 hours (which I eventually did with the U3), but just for the heck of it, I began playing music through it immediately. Headphones used were the HiFiMan 400i 2020 version, Sivga 007, Philips SHP 9500, Status Audio CB-1, and the Brainwavz HM5. Music being used for evaluation were various large orchestral classical, big band jazz, Latin jazz, and other larger orchestral varieties. For evaluation purposes, It is always a good idea to listen to large orchestras that feature a wide variety of instrumentation. This gives you a good reference point how an audio component can relay orchestral timbres of each instrument. Even upon the first turn-on, I was immediately struck by the musicality of the U3 and the ability for it to further separate various instruments with the proper air or space around their locations. Previously, when I listened to headphones through the likes of the iFi ZenDAC, Soundavo HP-DAC1, Micca OriGen G2, Fiio K5 Pro, and FX-Audio DAC-X6 Mk II, they all displayed different sound signatures - with some models displaying a very bright sound signature, while others sounded bland, and some being very good for the money. With the U3, I was now hearing instruments that previously were not noticeable because of the blending of the sound within the various orchestras. Small, quiet instruments such as cymbals, triangles, and others, were no longer buried behind the entire orchestra. Rather, they were lifted and open to where you could hear them distinctly. All the instruments playing - whether via a full symphony orchestra or a smaller, more intimate jazz group - had this openness to the performances. It was as if a substantial veil had been lifted between the listener and the music. Additionally, imaging (the placement of instruments on an imagery stage) was so precise that you could envision the musicians and exactly where they were located. Depth was also exemplary. However, do keep in mind that if you are running a horrible recording or a poor stream of lower quality music, the U3 will let you know. I should also add that this particular budget head amp is a great device to determine how good your headphones really are. Now do note that I've long discovered (and believed) that warming up/burning-in an audio device is essential because the sound signatures can change over time. When you first turn on the U3 and begin listening, it is very detailed (with the stock Op Amp that comes with it) and dynamic - and perhaps may sound bright to some. As time goes on - in my case being just 48 hours being left on all the time - the overall audio character warmed up - yet the sound was still detailed with plenty of dynamics. As an aside, you should leave your DAC's and/or Head Amps on all the time as they use negligible power. It's just not good to turn off and on (constantly) audio components, and you'll eventually discover that your audio components will have a longer shelf life in the process. Another positive aspect about the U3 is that musical instruments have an accurate timbre to their sounds - not colored at all. I kept mumbling to myself, "Is this thing really a thirty-something dollar head amp?" If ever there was a piece of audio gear that defied expectations (for the better), the U3 meets that scenario. Following my discovery of the U3's capabilities, I then wondered that if the U3 sounded superb with the likes of the entry level SMSL M100 or the Schitt Modi 3 DAC's, what would it do with far more expensive and higher end DAC units? In fact, in my opinion, I'd still call it a bargain if the U3 was priced at $100-$125 - it is that good. Like I said, it makes you now want to pair it with far better (more expensive) DAC's to evaluate the sound quality, which I can only imagine would be improved even more so. Look - I do quite a few blogs and reviews about various audio gear. This Douk U3 threw me for a loop - I found it that stunning, given its ridiculously low price. I strongly suggest picking one up before the price rises. I'm actually in the process of ordering a second one - mainly so I can change out op amps in one, while keeping the other with the stock op amp. At this price, it's a no-brainer. Given my previous experiences with evaluating high performing, yet very inexpensive audio items - which after a series of excellent reviews - were predictably followed by price increases by the vendor. I believe that once Douk sees the reviews on the U3, like anything else, they may very well raise the price. Now let's address the ability to easily remove and change out the Op Amps. This is something I had initially not considered doing with the U3, but since Douk specifically advertised this feature, that piqued my interest. So I purchased several Op Amps and tried them all. And yes, there were sound differences - some making the U3 sound brighter, some harsher, and some warmer. I found that upgraded Burson Op Amps - albeit a bit more expensive - did the best and noticeably elevated the sound performance of the U3. The Burson V5 version homogenized the sound, had a warmer upper register, yet still maintained excellent detail/definition, and had quite a bit of weight to the music. Also keep in mind (remembering about what I wrote above about allowing an audio device to be broken-in), when you switch Op Amps, as they warm up, their sound character will also change and usually for the better (meaning an increased warmth to the audio). So when you first insert an Op Amp in the U3, it may at first sound brighter, but don't let that dissuade you. Give it a few hours or up to 48 hours to be able to notice a discernible change in sound character. Be careful with op-amps though because if you insert it the wrong way (like backwards), you will immediately burn out/destroy the op-amp (not the unit). So before you do any op-amp rolling, PLEASE - be careful and know what you are doing. Given that, the op-amp that comes with the U3 is quite competent and musical sounding. Well, how about any negatives you may ask? Well, yes there is one (subjective) - and that is the front blue light which indicates on/off status of the U3, is rather large (and bright) when compared to the rest of the unit. It features an overly bright blue light which can light up a room at night (without exaggeration). When it's on, especially at night - and your sitting close to it such as by a desktop computer while listening to music - it can be extremely distracting because of its brightness. And when that light is "blue," somehow it becomes more pronounced. It would have been nice if Douk designed the light to be either red or green, which would have toned down the effect somewhat. So that's the only negative thing I can report really. I was so impressed with the U3 that I purchased a second one shortly after getting the first copy. Now when it comes to support - wow, are they good! After 4 months or so, one of my U3's developed a loud hum in the headphone jack. At first I thought it was the headphone I was using, but soon discovered that something happened with the U3. So here it was - June - and I contacted Douk via Amazon. They were quick to respond - didn't ask any questions - and sent me a new U3 in a jiffy manner. Now that's support to the maximum. So, based on its uncanny low price vs its ridiculously high performance ratio, I am enthusiastically rating the Douk Audio U3 mini head amp with 5 stars. It's just that good!!!!

### ⭐⭐⭐⭐⭐ Review
*by G***T on 16 June 2022*

Awesome amplifier, easily a thousand dollar sound selling for 2 figures, the signal to noise ratio is also extraordinarily impressive when powered by my power bank which is a DC power supply.

### ⭐⭐⭐⭐⭐ Review
*by P***É on 6 November 2024*

Excelente custo benefício

## Frequently Bought Together

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*Product available on Desertcart Japan*
*Store origin: JP*
*Last updated: 2026-02-22*