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HiFiMAN EF2A

Vacuum tube headphone amplifier/USB DAC

7 Reviews | 2 questions - 11 answers

Item # 818EF2

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Overview

Our take on the HiFiMAN EF2A

Plug the HiFiMAN EF2A into one of your computer's USB ports and prepare to be impressed. This compact digital-to-analog converter/headphone amp bypasses your computer's built-in DAC and audio circuitry — processing your digital music files outside the noisy environment of your computer for far better sound quality. The EF2A's vacuum tube headphone amplifier brings your tunes to life, imparting smoothness and clarity. You'll hear more dynamics and detail that you can really savor on your headphones. The EF2A also includes an analog audio input so you can enjoy improvements in sound with another music source. This is one component that looks so cool, you'll absolutely want to show it off on your desktop.

Add the magic of tubes to the sound of your music

Plug the HiFiMAN EF2A into one of your computer's USB ports and prepare to be impressed. This compact digital-to-analog converter/headphone amp bypasses your computer's built-in DAC and audio circuitry — processing your digital music files outside the noisy environment of your computer for far better sound quality. The EF2A's vacuum tube headphone amplifier brings your tunes to life, imparting smoothness and clarity. You'll hear more dynamics and detail that you can really savor on your headphones. The EF2A also includes an analog audio input so you can enjoy improvements in sound with another music source. This is one component that looks so cool, you'll absolutely want to show it off on your desktop.

HiFiMAN EF-2A

HiFiMAN's EF2A sports vacuum tubes for cool looks and hot sound.

What's in the Box:

  • Headphone amplifier
  • Two 6AK5 vacuum tubes
  • AC adapter with attached 56" cord (16V/0.8A)
  • 5' USB cable (with Type A USB on one end and a Type B USB on the other end)
  • Owner's Manual

Product Highlights:

  • uses two 6J1 vacuum tubes for amplifier input stage
  • Burr Brown PCM2702 digital-to-analog converter for high-fidelity stereo sound
  • durable metal chassis and front plate construction
  • external power supply included
  • USB (type B) input for connecting to a computer
  • supported sample rates: 44.1kHz
  • input bit depth: 16-bit
  • stereo RCA audio input
  • full-size stereo headphone output
  • recommended headphone impedance: 32-300 ohms
  • signal-to-noise ratio: 95dB
  • frequency response: 20-20,000 Hz (±0.2dB)
  • output at 32 ohms: 3V, 320mw
  • output at 300 ohms: 6.2V, 256mw
  • 5-11/16"W x 3-1/8"H (including tubes) x 4-1/4"D
  • warranty: 1 year
  • Our 60-day money-back guarantee
Reviews

HiFiMAN EF2A Reviews

Average Customer Review(s):

(7 Reviews)
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Details

Hands-on research

Product Research

Features

Overview: The HiFiMAN EF-2A is a hybrid USB headphone amplifier which combines vacuum tube sound quality with solid-state technology to deliver outstanding audio performance. The EF-2A has two inputs on the rear panel: a line-level CD input and a USB input. On the front, you'll find a 1/4" headphone jack, power switch, source switch (CD or USB), and rotary volume control. The EF-2A has a simple, but elegant, brushed aluminum faceplate and chassis.

Vacuum Tubes: The EF-2A uses two 6AK5 vacuum tubes (equivalent to the Chinese 6J1) at the input stage to significantly improve the condition of the source signal. The tubes have a flat frequency response and a high signal accuracy. The tubes are packed separately inside the box, so you will need to install them through the provided holes in the acrylic top panel. When installed, the tubes protrude approximately an inch.

Burr-Brown DAC: The EF-2A's USB input incorporates a Burr-Brown PCM2702E DAC (digital-to-analog converter) to improve the audio performance from your computer's headphone output. The DAC provides 16-bit/44kHz resolution, which is equivalent to CD quality.

Power Supply: The EF-2A uses an external power supply instead of one that is built-in. This keeps the size of the headphone amp small, and prevents noise generated by the power supply out of the chassis.

Key Components:

  • Volume Control: ALPS potentiometer
  • USB DAC Chip: Burr-Brown PCM2702E
  • Vacuum Tubes: Chinese 6J1 x2 (6AK5)
  • OP-amp: OPA2604

Specifications:

  • Input Impedance: 47k Ohms
  • Output Impedance: 32-300 Ohms
  • Output: @32 ohms: 3 V, 320 mW; @150 ohms: 6.2 V, 256 mW
  • Frequency Response: 20 Hz to 20k Hz (+/- 0.2 dB)
  • Signal-to-Noise Ratio: 95dB
  • Distortion: 0.2%
  • Power Consumption: <15W
  • Input Voltage: 16 volts AC, 500 mA
  • Power Supply: 110/220 Volts

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Q & A

Customer Q&A

2 questions already asked

I can't really help regarding Windows drivers for this DAC. I ise Mac computers and those see it as a Burr-Brown DAC without issue. I simply select it as my audio device under sound settings. I'd have to guess that it'll be a similar process with Windows as long as your OS sees it. It's a peripheral device, so i don't see any reason to disable or remove software to use it. I can say letting it 'burn in' for a day or two at moderate volume really wakes it up as far as SQ goes. I use only headphones with it. [ Michael  Feb 19, 2015 ]
Thanks for the input! [ Lonnie  Feb 17, 2015 ]
Well, that set-up is quite elaborat, having said that, I purchased this unit to play thru headphones. You know the old addage, sometimes "LESS IS MORE". Personally I would just use the download and play thru a stereo, even if it were just a decent desk top. Then use this unit to play in stereo mode, since that is what you are going to get anyway. Hope that helps ,although , that is probably not the answer that you wanted to hear...sorry! [ George  Feb 17, 2015 ]
Nope, no need to apologize... I appreciate the honest response and will look into what you said. Thanks for the input! [ Lonnie  Feb 17, 2015 ]
Dac will override your onboard....dac in this does not require driver support...your onboard is better imho. I would look elsewhere such as schiit magni 2 uber for headphone and preamp capabilitiea. You can use your onboard dac or with a 3.5mm to rca adapter or even look to the schiit modi 2/modi 2 Huber for outboard dac. Sorry for the opinion when you asked for information. [ THOMAS  Feb 17, 2015 ]
Hello, i own one and i am very happy with it. Nice warm sound with Tubes when they get warmed up. You can Plug and Play, Ez Pz! i switch it from laptop to PC with ease, it will automatically get drivers and will switch to default(if not, ez enough to set it) [ ALEXANDER  May 16, 2014 ]
It's just plug and go [ Derek  May 13, 2014 ]
I am using my HiFiMan EF2A mainly with my home audio system by connecting it's left & right audio connections to the tape connections on my surround sound receiver. I did connect my HiFiMan EF2A to my new Apple iMac briefly, just to see if it worked, and it did--no problem. The computer recognized it while it was plugged in and it showed up on the "Sound" page in System Preferences. I had to select HiFiMan to use it and then go back and switch to iMac Internal Speakers when I was finished checking the HiFiMan, however. I didn't have to acquire any drivers for it to function on my iMac, but it's a new model and I don't know if another type of computer or an older model might require them. You might try calling the maker of the computers where you work and ask them. BTW: According to reviews online, the HifiMan EF2A is supposed to be a very good choice, for it's price, and I think it looks really cool. Not sure about the audio quality yet because it is new. It sounds all right so far, but it's a tube model and I understand from reviews that you have to burn the tubes for a number of hours before it is broken in. The sound is then supposed to improve quite a bit. (Supposedly one can get a "warmer " sound with tubes, as opposed to digital.) Also I am told you can try different tubes, including vintage ones, to tailor the sound to your preferences. The Tube Maze folks online are very nice and can advise you on the world of tubes. Hope this helped- [ George  May 12, 2014 ]
Just plug and go Sean. The sounds are great! [ BRIAN K  May 12, 2014 ]
It is pretty simple: plug and play. No driver installation is needed. [ Ryszard  May 12, 2014 ]
You will have to download a driver for the burr brown chip. When I plugged it in it automatically downloaded much like any USB stick would, no real huge software program, just a driver. Any setup is done through windows sound panel. [ ERIK  May 12, 2014 ]
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