Mini Bluetooth 5.0 Tube Headphone Amplifier USB DAC Stereo Audio Preamp APTX-LL

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Mini Bluetooth 5.0 Tube Headphone Amplifier USB DAC Stereo Audio Preamp APTX-LL


  • Douk Audio U4 is a multi-function HiFi audio device, with Bluetooth 5.0 and USB input, stereo RCA, 3.5mm AUX, 3.5mm headphone jack output, which can be used as a Bluetooth receiver, a USB DAC, a headphone amp and a stereo preamp, compatible with phone, computer, power amplifier, active speakers and so on.
  • Adopting classic 6N3 vacuum tube(much better than 6J*) to effectively eliminate the harsh digital sound, providing HiFi clear, soft and smooth, warm and sweet tube sound. The sound field is wide, especially suitable for vocals, strings, light music, classical music, etc.
  • Bluetooth 5.0 (QCC3008 chip) supports APT-X, APTX-LL, adding classic TDA1543 chip for decoding and external high-gain detachable antenna, makes its sound transmission low-delay and lossless.
  • USB sound card part uses CM6642 chip, supports 24bit 192KHz transmission, compatible with Windows / Mac / Linux system and Android mobile phone with OTG function, no need for driver, plug and play. Headphone amp uses classic MAX9722 decoding chip, 300mW output power can drive most 16-600 ohm headphones.
  • Super mini size and exquisite appearance, with power and select switch, working indicators and volume control. Using all-aluminum chassis CNC machined and laser carving, looks fashionable and powerful, perfectly suitable for your desktop or a smaller space in your home or office


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More Tube Amplifiers To Choose From

Willsenton R8 KT88/EL34 x4 Tube Integrated AMP Power Amplifier Headphone (Silver)
  • One amplifier can used wiht tube EL34, KT88 or 6550, so, you can get 3 kinds of sound from different models tubes. The default matching tubes of this machine is KT88. If you need another 2 new sets of tube, please purchase in addition. There is a Red selection button on the Back of the amp to switch.
  • Pure hand-made, Point to point manual welding.
  • Willsenton R8 is an integrated Amplifier, it is a Power Amplifier too (there is a group Power amp input), it is a Headphones amp too.
BoyuuRange A50 MKIII 300B HiFi Intergrated Tube Amplifier Single-end Class A Valve Amp with Tube Cage
  • Factory add an Inductance transformer and Bipolar filter circuit to get the nicer sound for the MKIII.Come with a Tube Cage and VU meters.
  • Power output tube: 300B × 2
  • Power Transformers: new imported 0.35, stack thickness 60MM (114-60).
Reisong A10 EL34 Hi-Fi Audio Stereo Tube Amplifier Single-end Class - A Amp
  • Please pay attention before buying, We received feedback from many buyers, reflecting that Reisong A10 Amp have not enough power. Please confirm that your speaker is a bookshelf speakers with a sensitivity 89db or more. We don't think Reisong A10 work well with a floorstanding Speaker or the low sensitivity speakers.
  • Manual welding, preferred audiophiles, output transformer switch to the 76x40 higher end output transformer.
  • If there is no sound from the machine after waiting for a few minutes, Please make sure the power is connected properly. And try pressing the Black Circle Button on the back of the machine (for switching between AUX and CD modes)
Design of an Integrated Push-Pull Tube Amplifier Made Easy
  • Amazon Kindle Edition
  • Amato, Giuseppe (Author)
  • English (Publication Language)

Last update on 2021-07-06 at 23:10 PST/ Affiliate links / Images from Amazon Product Advertising API

Learn About The Tube Amps And How They Work

Chances are you’ve just bought your first Electric guitar and wish to find out all about guitar amps. Maybe you’re just curious as to how long amps have been around, how they work, or which to purchase. Whatever the reason, by reading this article, you’ll get answers.

History of the Amplifier

Guitar amps have been around for roughly 70 years now, having first appeared during the 1930s. The earliest amps had very poor high treble and bass responses. This was improved over time, as amps became better developed. During the ‘60s, the guitar amp greatly evolved to where it is today when guitarists of that era experimented with deliberately overloading their amp to create Distortion. From that point on, most amps were provided with preamp distortion controls. Playing with distortion has since become an important part of Electric guitar playing

Types of Amplifiers

There are two types of amps: solid state and vacuum tube amps. Additionally, there are some amps that combine both solid state and tube technologies. Most amps, especially the least expensive ones, are solid state because they are lighter and easier to repair than tube amps are. A lot of guitarists, however, prefer the tube amp due to the tube amp’s analog sensitivity, which they claim makes tube amps sound better. While this is probably the case, most beginners can’t afford to shell out the $500-$1000 it costs to buy a good tube amp. That’s why solid state amps are actually a good buy in some cases.

Solid state and vacuum tube amps come in combo (speakers and head) packages or separately. Guitarists who aren’t picky can just buy the combo, while those who are picky can “mix and match” heads and speakers. This is useful for those looking to achieve a certain sound.

How Amps Work/What Watts Mean

Without going into a big, long, technical explanation, amplifiers basically take the vibration (sound) of the string(s) and amplify it, thereby increasing the sound. If you wish to find out more about the technical side of guitar amps, there are several good books that cover the topic pretty thoroughly.

Each amplifier has a certain number of watts. The higher the number of watts, the louder the sound produced by the amp is. Generally speaking, those who wish to play shows will want to get amplifiers with at least 30 watts, preferably at least 50 watts, especially if they plan on playing at larger venues.