Earlier this year, I received a sample of xDuoo’s MT-604 fully-balanced tube headphone amplifier from online retailer Apos Audio. At an asking price of $169, it offers more sexiness per dollar than almost any audio component I’ve seen. I couldn’t wait to photograph it, and find out if it delivered on its promise of delivering enchanting tubed sound at a very low cost.
The MT-604 is a class-A, hybrid tube/solid-state amplifier. It’s rated to an output up to 200mW (at 32Ω) of power, which is said to work with even hard-to-drive headphones. Its features include a built-in mute circuit and independent left and right volume controls. A solid-state amplifier is said to provide “large dynamics, high speed, and resolving power.” On the MT-604’s rear is a pair of stereo balanced inputs. Front-facing output terminals are XLR and 4.4mm. The MT-604’s tube complement is four 6J1s, all located in its preamp section.
Not surprisingly for its cost, the MT-604 is not the most resolving or tonally accurate headphone amp out there. Instead, it delivers a beautiful and warm midrange and has an overall presentation that’s extremely fun and easy to listen to. It would be fantastic choice for a new audio hobbyist or even a solid-state veteran who to wants to experience a little tube magic in their audio pursuits for little money. Let the tube rolling begin!
The xDuoo MT-604's tube complement.
The MT-604 can drive a wide range of headphones via its dual outputs.
The warm glow of tubes provides an appealing sonic signature.Howard Kneller’s audiophile adventures are documented on his YouTube channel (The Listening Chair with Howard Kneller) and on Instagram (@howardkneller). His art and photography can also be found on Instagram (@howardkneller.photog). Finally, he posts a bit of everything on Facebook (@howardkneller).
