Shanling UP4 Bluetooth DAC/Amp – Review

Shanling’s UP4 is a Bluetooth DAC/Amp that allows you to improve the quality of your favorite wired headphones without the extra wires. Shanling’s previously released bluetooth device, the UP2, along with the non-bluetooth UA2, were both very well-received in the audiophile world, setting the bar high for the UP4. Let’s take a look at this handy device, which runs for $99, and see what it’s all about.

What’s in the Box

• UP4 DAC/Amp
• USB-C to USB-A charging cable
• Case with clip

Design

The UP4 uses Bluetooth 5.0 and up to 15 hours of battery life. Its LED lights up based on which codec is being used, colored as follows: LDAC, HWA, aptX / aptX LL, aptX HD, SBC, AAC. It supports up to 96 kHz / 24 bit, and uses two ES9218P audio chips. The UP4 also offers three gain settings and four different digital filter modes that users can switch between with the click of a button. 

Build

The UP4 has a similarly strong, sturdy build to many portable DAC/Amps I’ve used in the past. The addition of the clip on case is a thoughtful choice, and makes it extra easy to walk around with this clipped to your belt or pocket while offering easy volume adjustment. The volume knob is very small, and at times I felt I’d have preferred a more protruding knob, but I understood the goal of making this unit as low profile as possible. 

Functionality

The UP4 is very straight forward and easy to use, pairing quickly and switching modes without any hassle. I do think this unit could benefit from one extra button, so there’s separate controls for the gain modes and digital filters, along with a small LCD display. At times, the LED light color system got confusing, given that the green, blue, and yellow lights can all mean three different things. This just takes some getting used to and a slight learning curve, but in less than a day of use most of my confusion was cleared up.

Sound quality

The UP4 leans into a more transparent sound with some very light grooming. I tested it with the Kinera Nanna, Final Audio A3000, and Sennheiser IE300. The high end seems to get extenuated at times, and the mid range tightened up a bit. It’s the type of sound altercation not all will find obvious, but many undoubtedly will. 

The output of this unit was one of its greatest strengths. While bluetooth audio can sometimes lack volume, the high gain and Dual DAC/Boost gain settings ensured I was never at a loss for loudness. It did require a bit of turning up, and with very high impedance headphones, this might not be enough to get the volumes into the extremes, but should be able to get it to standard levels. 

In terms of the different digital filters, the difference in timbre between them will be extremely subjective and is especially hard to define. I can say the minimum phase slow roll-off filter tended to be my go to, as it felt to clean up the high end the most. The linear phase fast roll-off filter was my favorite to use for a slightly warmer sound, and tamed the high end and resonance just a tad more than the others. The differences between these filters and where each is best applied is something most listeners will take a while to get attuned to, but the more I got to know each one, the more I appreciated all the extra options. 

Overall

The UP4 exceeded my expectations in terms of sound quality for a bluetooth device, and made me reconsider some of my aversion to amps in this growing category. Not having the extra cable between your DAC/Amp and device cleans up and simplifies your setup more than you might think, and the UP4 ensures you sacrifice as little as possible for its advantages. 

Pros:

• Small, durable build

• Noticeable sound quality upgrade

• Numerous filters and gain options

Cons:

• Confusing user interface

• Small volume knob 

• Output could be higher (though is still impressive for bluetooth) 

You can purchase the Shanling UP4 at Audio46