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Get the most out of your high-performance headphones

Just like great speakers, top-notch headphones need high-quality power in abundance to perform their best. Give them what they crave with the HiFiMAN EF-5. This hybrid vacuum tube/solid state headphone amplifier dishes out the kind of juice that can drive even the most power-hungry cans. You'll hear dynamic, detailed sound with the warmth and clarity of tubes, plus the added bass punch and slam of solid state power. Its wide bandwidth, low distortion, and high signal-to-noise ratio make the EF5 the clear choice for discriminating music lovers.

hifiman ef-5 back

Unique two-box design

The EF-5's dual-chassis configuration uses a separate outboard power supply that helps isolate noise and interference from the amplification circuitry. The amplifier chassis sports a clear plexiglass top and tube cage that protects the dual triode 12AU7 input stage and solid state outputs while allowing you to admire its tidy, well-crafted interior. The two pieces can be placed side-by-side, or stacked to save space. Any way you use it, this is one cool-looking, fantastic-sounding headphone amp you'll be proud to show off.

Product Highlights:

  • hybrid tube/solid state design uses a single 12AU7 dual triode vacuum tube input stage and OPA275 solid state opamp output
  • dual-chassis design with separate headphone amp and power supply blocks
  • high-output design ideal for high-performance headphones, including HiFiMAN HE-500 and HE-6 planar magnetic models
  • stereo RCA audio input
  • full-size stereo headphone output
  • compatible with 2-2000 ohm headphones
  • signal-to-noise ratio: greater then 95dB
  • frequency response: 20-30,000 Hz
  • output at 32 ohms: up to 15 Volts
  • THD+N: less than 0.2%
  • amp chassis: 4-3/8"W x 2-7/8"H (with tube) x 9-1/2"D
  • power supply chassis: 4-3/8"W x 2-1/16"H x 9-1/2"D
  • warranty: 1 year
  • Our 60-day money-back guarantee

Why buy a headphone amp?

High-performance headphones need high-quality amplification to perform up to their full potential. If you connect them directly to the headphone jack on your computer, iPod®, or stereo receiver, you may be disappointed. A separate headphone amplifier sends a stronger, cleaner signal to your headphones.

HiFiMAN EF5 Reviews

Average Customer Review:

1 Review

HiFiMan EF5 Vacuum Tube Headphone Amp

Written by: Donald from NY, NY on May 11, 2013

Crutchfield Customer Review (What's this?)

I am using the HiFiMan EF5 with my HiFiMan HE500 headphones. I bought the unit without a listening test based upon the reviews it had received. Since I am using the HE500's it made sense to add another HiFiMan product to the sound chain. I am delighted with my purchase.

This amp gives out a sound that I have only heard with amps priced at the $1500-$2500 level. I am using it with the Meridian Explorer DAC with upgraded connectors by audioquest. I am intending to upgrade the power cable and my speaker headphone cable as well. I cannot even imagine the quality I will get out of this set up once I do that.

Of course I know that sound is only as good as the weakest component in the chain, and the EF5 is clearly NOT a weak component. At the price, this amp is an audiophile bargain! I wanted a good headphone amp without spending 4 figures and WOW did I get one!

Pros: quality sound, price, amp/pre-amp separation

Cons: portability, amp/pre amp separation

Hands-on research

What's in the box?

Download owner's manual

  • EF-5 Headphone amplifier
  • 12AU7 Vacuum tube
  • DY-1 Power Supply
  • 39" Power cord (3-prong / IEC 3-pole)
  • 30" AC power connecting cord
  • 2 Acrylic tube protectors (1 installed)
  • Allen-head screws (Length=9mm)
  • Owner's Guide

Product Research


Overview: The HiFiMAN EF-5 is a hand-built high performance hybrid headphone amplifier, designed for use with high-end and hard-to-drive headphones. It combines vacuum tube sound quality with solid-state technology to deliver outstanding audio performance. The EF-5 comes with a separate DY-1 Power Supply, which can be positioned beside or stacked below the EF-5. The EF-5 has a stereo RCA input on the rear panel. On the front, you'll find a 1/4" headphone jack, power switch, and rotary volume control. The EF-5 and DY-1 each have a black acrylic faceplate and a brushed aluminum chassis.

Vacuum Tube: The EF-5 uses the 12AU7 Full Music vacuum tube at the input stage to significantly improve the condition of the source signal. The tube has a flat frequency response and a high signal accuracy. The tube is packed separately inside the box, so you will need to install it through the provided hole in the EF-5's top panel. When installed, the tube protrudes approximately 5/8" above the EF-5.

Note: The 12AU7 tube takes approximately 60 seconds to warm up. A blue LED behind the front panel will glow when the EF-5 is ready to use.

Key Components:

  • Vacuum Tube: RCA Clear Top 12AU7
  • OP-amp: JRC5532 OPA275


  • Input Impedance: 50k Ohms
  • Output Impedance: 2-2k Ohms
  • Output: @32 ohms: up to 15 V
  • Frequency Response: 20 Hz to 30k Hz
  • Signal-to-Noise Ratio: >95dB
  • Distortion: 0.2%
  • Power Supply: 110 to 240 Volts
  • Dimensions:
    • EF-5 Headphone Amp:
      • Width=4.344"
      • Height=2.25" (2.875" w/tube)
      • Depth=9.5"
    • DY-1 Power Supply:
      • Width=4.335"
      • Height=2.003"
      • Depth=9.5"

Our Product Research Team

At Crutchfield, you'll get detailed, accurate information that's hard to find elsewhere. That's because we have our own in-house Product Research team. They verify what’s in the box, check the owner's manual, and record dimensions, features and specs. We stay on top of new products and technologies to help people make informed choices.

Customer Q&A

1 question already asked

I would connect it to any fixed(not controlled by pre amp volume control) line out. There are no cables included. Any quality rca patch cable will work. [ Mike  Mar 10, 2015 ]
No, you will need your own cables. You just hook them up the same way as you would a regular amp. [ Donald  Mar 10, 2015 ]