REVIEW: HIFIMAN EF2C HYBRID HEADPHONE AMPLIFIER/DAC

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capetownwatches

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HiFiMan is better known for producing excellent Planar headphones certainly, but has come up with some  quirky and interesting  headphone amplifiers as well.

The EF2C is a compact hybrid headphone amp with built-in DAC which utilizes two 6J1 type tubes in its input stage to add a bit of tubey warmth to its sound signature.
It's an attractive and extremely well put together little unit that is designed as a one box desktop solution to improving the sound from one's PC or MAC.
So does it achieve this aim, or is it yet another cheap Chinese made gear that falls short on producing the goods where it matters?

Specifications:

? Input Impedance: 47K Ohms
? Output Impedance: 32-300 Ohms
? Output at 32 Ohms: 3v, 320 mW
? Output at 150 Ohms: 6.2v, 256 mW
? Max. Power Output: 600mW @ 35 Ohms
? Frequency Response: 20Hz ? 20 KHz
? Signal to Noise Ratio: 95 dB
? DAC: Burr-Brown PCM2702
? CM102S USB DAC 16-Bit Stereo, 48 / 44.1 KHz
? Tubes: Stock Chinese 6J1 x2 for the input stage
? Line-in Maximum Output: 4.6 V; Distortion: 2%
? USB DAC Maximum Output: 3.2 V; Distortion 0.46%
? Power Supply: 110v/220v (AC 16V)
? Dimensions: 144 x 110 x 78 mm (WDH)
? Weight: 1.36 kilograms



Setup was easy enough, since the CM102S USB interface operates on USB 1.0 protocol and requires no software for the Burr-Brown PCM2702 DAC chip to do its thing in typical plug and play manner.
Unfortunately I found this implementation to be less than stellar, and  the single biggest downfall of this otherwise very impressive little amp.

Output was thin and sounded as if there was some form of digital shenanigans happening in the background. It was acceptable but not optimal, and I used the unit as a pure amplifier going forward, easy to do since Hifiman provides a pair of RCA inputs to connect to an external DAC, selectable by a front panel pushbutton.

Driven by the Sabre equippped Audio-gd NFB-11 things improved dramatically.
With the very good volume pot at between 1 and 3 on the dial the EF2C sounds open and substantial, with excellent channel separation and a dark background providing lots of detail.
I was very impressed by the dynamics and overall easy to listen to presentation once DAC duties had been subjugated.



Listening to Lee Ritenour's excellent Rhythm Sessions in Redbook FLAC was most pleasing, with a tight and punchy bass, very smooth and agreeable midrange and open and detailed highs.
Just a touch of grain there, quite acceptable considering the tube output, which adds just enough warmth to the otherwise forward presentation.
Complex rhythms are well handled and each instrument could be clearly placed in the mix.

Trying some classic rock was equally satisfying. The Allman Brothers' magnificently produced Shades of Two Worlds in 16/44.1 FLAC was a good test of the EF2C, with Dicky Betts' languid slide guitar a pleasure to listen to, along with the complex percussion that is a trademark of the band. Drums and cymbals were heavy and crisp at the same time, and I ended up listening to the entire album with a smile on my dial, marveling at how such an innocuous little box could perform to such a high standard.

Rolling the stock Chinese 6J1 tubes for 2 x NOS RCA 5654 made a slight difference to my ears - greater smoothness and detail retrieval along with slightly less punchy bass.



Judging the EF2C as a budget priced ($169 currently) entry level unit, I feel that it delivers everything a beginner audiophile might desire in such a setup and is a significantly better desktop solution than using your computer's DAC.
As an aside, it runs VERY hot, and I would recommend removing the Plexiglas cover for normal operation in order to improve cooling - strangely it has no vents in the casing. I found the following online, but cannot attest to its veracity:

"Don?t think that just because it is small, this amplifier isn?t powerful nor durable. It is possible to use it for 200 hours, without turning it off and all components will withstand this amount of pressure!"

Yes, compared to more expensive gear it does fall short in terms of ultimate resolution and detail. But that is not its mandate.
It is powerful enough to drive my HD600 and K612 perfectly well, and has sufficient voltage to do justice to my K171 MKll (94dB/V SPL @ 1mW)

For the R2,000 it cost me I had great fun with it as a alternative to my solid state gear. It is particularly satisfying with Jazz, soft rock and Pop genres.
If one does not listen too critically and simply wants a classy upgrade to one's computer sound for very reasonable money, the EF2C delivers in spades.



Here are some impressions I found on the interwebs - I would recommend the proverbial "grain of salt" be applied...

"Note that after breaking it in, the HiFiMAN EF2C is a completely different creature, offering a clearly vintage and melodic sound."
Low range: high-bass is very present, even puffed up during the first 200 hours of use, then gets back to an enjoyable level. The infra-bass is a little short but transients are very good, which is a rather rare quality. Bass lines and guitars are very satisfactory.
Medium range: rich and warm, very convincing in the low-mediums with a very good restitution of human voices.
High range: smooth but slightly in the background. In other words, treble is really well handled as too much high frequencies can have a negative impact on the depth of the sound stage and make it too tight. This is not the case here. Here is a headphone amplifier that will work well with many treble oriented earphones and headphones.
"The coherence as well as the overall balance of the sound are much superior to what more expensive DAC amplifiers have to offer."
"The soundstage is very wide and the dynamic range is outstanding, but the amplifier remains undaunted. Muddy Waters? guitar resonates wonderfully."
"Let?s go straight to the point, the EF2C has an obvious sense of rhythm."
"A truly melodic headphone amplifier."

Tristan Jacquel - blog.son-video.com

"The HiFiMan EF2A offers a great and warm tonal output made better by the power tubes that should satisfy every seasoned audiophile."
samma3a.com

"The data we measured proved to be much better than indicated by the manufacturer in the device?s passport. The manufacturer indicated a signal/noise of 90 dB, and we got 96 dB. The manufacturer indicated 2% distortion, we received 1%. And this is with a sufficiently high level of the signal at the output, typical for real operating conditions."
"Quite unexpectedly for us, the Hifiman EF2C amplifier is quite successfully combined with expensive DACs, at a cost of more than $ 1200, and with expensive headphones ? the difference with cheap ones is well audible. Therefore, the Hifiman EF2C is suitable for anyone who wants to diversify their collection of equipment with the tube sound of a headphone amplifier."

reviewzorro.com

"Compared to its size this amplifier is really something and factoring in the cost it is a very complete package."

8.6
OVERALL SCORE
techpowerup.com






 

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