The EF5 is not a neutral sounding amp. On stock form, it’s slightly warm and mellow sounding. It’s not excessively mellow, and as some other tube amps can be, and so it’s still a decent amp to play fast-paced music with. If you listen to Rock, Jazz, Accoustic, RnB stuff, then this amplifier is something you need to try. For classical, electronica, and faster paced Rock, I’d still recommend something with more PRaT like the Burson HA-160, although that sells for almost double the price of the EF5.
The soundstage performance is surprisingly very good for something at this price level. I tried the EF5 with a number of different headphones, and it maintained a good soundstage image on any of those pairings. The EF5 also tend to smooth out and mellows out the treble area, which is part of the reason it works well with headphones like the HE5 that tend to be harsh and agressive on the top frequency.
Despite the non-neutral color of the EF5, the coloration is very likable, and so I’ll be recommending this amp to those of you looking for an entry level desktop amplifier with a full midrange and warm sound signature. It may not compete with the refinement of higher priced amps, but for the price, the EF5 gives a sound that’s hard to dispute or not like. The power output is also very high, and the EF5 can drive the HE5/LE headphones, which are two very hard headphones to drive, with such an ease. At the price the EF5 is selling for, it’s hard to not like it. The EF5 is available for $399 from Head-Direct.com
Gear used for review:
Headphones: Hifiman HE5LE
Amplifier: Hifiman EF5
Source: HRT Music Streamer II+
Transport: Acer Aspire One, Ubuntu Linux OS and ALSA Player.