HiFiGo Muse HiFi M5 Ultra Bluetooth Portable DAC & AMP, Headphone Amplifier with Low, Medium, and High Gain Modes and 7 Filter Mode Adjustments (M5Ultra)

Excellent look, feel and sound! First, I had an issue having accidentally ordered two of these units. Even though HiFiGo indicates that they are not returnable, they were wonderful to work with and accepted the return and gave a full refund. I have read HiFiGo customer service is excellent and I have to say that my experience with them was also excellent.The Muse looks wonderful. The case looks really expensive being comprised of metal and glass. The see through front revealing the circuit board is really elegant looking and the tube glow, when in tube mode, is really cool. The included instructions are excellent and easy to understand and the unit is very intuitive so figuring out the features without the instructions is relatively simple. Nice that is includes a really high quality case to protect the unit. The case looks like leather. Also comes with the dongles and adapters you might need. Overall, I have to give the packaging an absolutely A+++.I fashion myself as somewhat of an audiophile so I tend to be critical of units I have reviewed. I have only praise for this unit. I purchased it principally because I love the tube sound. I own another portable tube headphone amp but its way heavier and must more bulky than this little palm size unit. It's easy to switch between tube and transistor sound while listening. While there is a difference, it is subtle and I must say that the tube sound is incredibly full bodied, spacial and just that much better than the typical transistor sound. The transistor sound for this unit is on par with other units I own most of which cost much more than the Muse. I found that it had the power to run any Headphone or IEM i threw at it and ran everything quite well.The Muse M5 Ultra is a unit you must purchase if you are a critical listener who Loves the tube sound or even just someone who wants much better sound than their phone can provide them. It's a fantastic unit at what I feel is a bargain price and I know that if I ever have an issue with it HiFiGo customer service will be there to assist. This unit gets an overall A+++ from me and I recommend it to others.

The unit arrived with a defective 4.4mm balanced headphone jack. There was no audio signal in the right channel. I returned the device for a refund.

I was looking for a solution to my old question - a DAC that doesn't hiss with Orion Ck by Campfire (14Ω Impedance x 113 dB SPL/mW) and Campfire Audio Lyra (17Ω Impedance x 102 dB SPL/mW) headphones. I consulted with Muse tech support. Of course, they could only guess, but they were right. This DAC can really be used with these headphones. But there is a feature - I liked Lyra with it more :)

Very nicely built

If you’re like me and you find the multiple Bluetooth codecs a big selling point be warned.I have been very disappointed in the poor performance of the Bluetooth connectivity with LDAC and all aptX codecs performing the worst with audio cutout starting at one meter (3 feet) away from the audio source/phone.According to the Muse representative, this device is not guaranteed to work with anything other than a phone.If you’re planning to use a wired connection then you’ll enjoy overall performance and sound quality.However, I do feel the tube feature is more of a gimmick. You can instantly A-B compare when swithching from VT (vacuumed tube) mode to TM (transistor) mode and the I find the difference subtle at best.I recommend the new Fiio BTR17 if you’re looking to utilize higher bitrate Bluetooth connectivity.