Centrance has crafted one of the most versatile DAC/amp units available today with desktop-grade power in a portable unit.
Pros: Tons of features -- tone controls inc. impedance and gain. 2x input options & 4x output socket combos. Desktop power in a portable device.
Cons: Power sacrifices battery life. Too bulky to use with just IEMs. A bit of hiss with low impedance cans even on low gain.
When Michael Goodman first told me he was going to make a portable device that used full-sized XLR jacks for balanced headphones, I thought that it was going to be too big and bulky. Wisely he asked the community for feedback on the design (maybe more so because it got a lot of people excited about it). When people were asked what they wanted, the answer was, inevitably, everything and the kitchen sink. And with two full boards of electronics alongside a large battery crammed into the case, that's what we got, with 8 different combinations of inputs and outputs available and the ability to handle everything from sensitive IEMs through to demanding full-sized headphones.
The only thing we didn't get was a long battery life, as that ended up being sacrificed for power instead. And power it has aplenty, presenting a wide and spacious sound through everything from low-impedance and low-sensitivity planers through to high-impedance HD-800s, with audio sourced from either a computer through its asyncronous USB input, or its second input, which at the time of purchase you have to choose either an iDevice-compatible USB socket or an optical digital input. While the former can be used with Apple's devices, the latter can be used with anything that has optical digital output, including quite a few DAPs these days, such as the Astell&Kern series.
The other choice you have to make at purchase time is what outputs you want. For that 4 different output selections are available:
- The 4XL with a 4-pin XLR and large and small headphone sockets (the latter of which doubles as an optical digital output for USB passthrough -- didn't I tell you "everything and the kitchen sink!);
- The RSA, which puts an "RSA"-style balanced headphone socket in place of the 4-pin XLR (such as used by Ray Samuels Audio, ALO Audio and Cypher Labs);
- The original "Combo" which uses Neutrik Combo jacks which can either be used as regular headphone sockets or as a balanced headphone output;
- and the Pro version with regular male 3-pin XLR sockets for DAC/pre-amp use.
Given that Michael Goodman has a background in pro audio, the sound from the M8 is very nothing-but-the-facts neutral, but I wouldn't call it unpleasant in any way. It uses an AKM DAC, which I'm particularly fond of as they are, to me, some of the least digital-sounding type of DAC out of all the Delta-Sigma types available. However, the options don't stop there, as Michael has included both a bass and treble booster switch, both of which have two positions: A bit and a fair bit. That allows a bit of fine-tuning of the sound, something we often *cough* do with expensive aftermarket cables.
That allows great portable, or compact desktop sound, though there are two caveats here: First, it isn't suited to long-haul flights, due to the battery life. If you're thinking of taking the power brick to plug in between the seats, it is pretty large and bulky. Second, it has a bit of hiss with sensitive IEMs, even on the lowest gain and impedance settings, so I'd wait for the Mini-M8 if that is all you're going to use it for.
If not second-hand, the M8 is sometimes on sale. I picked mine up in a Valentine's Day sale for 30% off, but I had to wait a few months for it! That meant it arrived about the same time as a loaner Hugo! Regardless, despite using the vastly more expensive and sophisticated, Hugo I am still impressed with the sound quality from the M8, so I've decided that I will keep it. It looks like it will have some challengers in the near future though, especially from iFi with their new Micro...