I've had the MHA150 for 3 years, and haven't written up a full review. Thanks to @EagleWings for encouraging me to finally put this together. My impressions on the MHA150 have changed a bit as I've tried loaner amps and new headphones, and will no doubt continue to evolve, though it's probably safe to say that new gear syndrome has worn off. The internal DAC is where most of the McIntosh flavor comes from in this unit. I'm told that it's based on an ESS chip. It has a "WOW" factor that's fun, sharp, intense, and a bit U shaped. With a soft headphone it's great for a while, but it regularly gets fatiguing, especially with more prolonged sessions. I'm usually listening for at least several hours a day, and fatigue becomes a problem. I added a Modi Multibit and then a Yggdrasil via AudioQuest Red River XLR cables, which is initially less exciting, but more natural and easier to spend long sessions with. I only use an Eitr or Pi2AES with the internal DAC because the built-in USB implementation will deliberately fade-in from silence, even in the middle of a song. I can't understate how irritating this is, especially from a device in this price range. The amp section is mostly neutral, and oozes power and control. It's also quite versatile, with 7 impedance/gain combinations and up to 50 watts per channel into 8 ohms. There's also bass control, which I love and use often with some headphones. Only recently I've been using the crossfeed feature, which can help reduce brightness. I haven't yet used it with speakers. As much as I want to get more into speakers, my home office would be a disastrous listening room. While the blue meters are cool, I'm not a huge fan of the look of the amp. It's solid, heavy, and well built, but ECP's modern design language is much more my style. Pi2AES → MHA150 → HE1000 Hearing this paring is what prompted me to get the MHA150. It pushes all of the right buttons, and to my tastes doesn't do anything wrong, even 3 years after first hearing it. The intensity of the DAC offsets much of the softness of the HE1000. Extension on both ends is extreme. It's particularly extraordinary with atmospheric electronic music. Pi2AES → Yggdrasil → MHA150 → HE6se +5db bass boost This is the most fun I've had with a headphone. Many say that they prefer using the speaker taps, but I prefer using the TRS jack. The volume levels during listening are nearly identical, I don't think the HE6 has access to any extra power from the speaker taps. Pi2AES → Yggdrasil A2 → MHA150 → Utopia The Utopia doesn't usually do well with solid-state amps. It's too lean, has a metallic timbre, and feels abrasive. Thanks to @E_Schaaf and the loaner program, I was able to spend a few weeks with the Feliks Euphoria, which showed me how much potential the Utopia has. Dekoni Elite Hybrid pads, when used with the MHA150, give a similar-ish presentation to the Euphoria, save the tubiness. However even after pad-rolling, I prefer a tube amp with the Utopia. Pi2AES → Yggdrasil → MHA150 → HD800S +5db bass boost HXD I've been trying for a while to understand how to appreciate the HD800S. The Crossfeed reduces brightness and the artificially wide soundstage. Even so, this not a satisfying pairing. It's tough to recommend the MHA150 because of the price. I'd like to compare it to the ECP DSHA3F Ravenswood 3F. If I get the chance, I'll be sure to update this post.