Every day more and more people are “cutting the wires” on their portable audio setups and going wireless. Shanling already impressed us with their UP2 and today we’re going to take an in-depth look at the Shanling UP4 Hi-Res Bluetooth amplifier.
The UP4 has a lot of interesting features, such as Dual DACs, Bluetooth 5.0, a built-in microphone, external USB-DAC functionality and more.
This sample was provided for the purpose of an honest review. All observations and opinions here are my own based on my experience with the product.
Shanling UP4 Review
Clean, transparent sound
USB DAC functionality
Dual Hi-Res certification
Dual DAC mode
Currently no app support
Package and Accessories
The packaging is simple and unpretentious, starting with a small, black box with yellow highlights and an image of the UP4 on the front.
Open the box and you’re greeted with the UP4 seated in a black foam insert, just like we saw with the UP2. The accessories which include a plastic clip case and USB Type-C cable can be found underneath.
Build Quality and Design
If you’ve owned any Shanling product from the last few years, the UP4 should look pretty familiar to you. The iconic volume wheel is there, as are the 2.5 D glass panels on the front and back of the aluminium frame.
With physical dimensions of 60mm * 36mm * 13.5mm (about 2 fingers wide) and weighing just 37g, the UP4 is very compact and lightweight. On the front panel is a single LED indicator that displays different colours corresponding to the currently used codec, for example, cyan means it’s using AAC and green means you’re rocking out with LDAC.
On the bottom panel is the USB Type-C port which is used for charging and connecting to a PC to use as an external USB DAC. The top panel contains a 3.5mm headphone out, a 2.5mm balanced headphone out, the built-in Knowles SiSonic microphone and a mode button. The mode button is used to switch between the various gain settings (low, high and Dual DAC/boost) and the 4 digital filters.
Finally, on the right side is the volume wheel which is also a button. A long press on the button powers the device on or off. Playback controls are via this button too: single click to start/stop playback, double click goes to the next track and triple-click for the previous track. This same button is also used to answer/cancel phone calls.
Sadly there is still no phone app available but Shanling says it’s coming: just like they (ahem) said there would be one for the UP2 which has still not materialized. Luckily, the UP4 (and UP2) is fully functional without the app but it’s something they should address ASAP.
In charge of audio duties are dual ESS Sabre ES9218P DAC chips supporting up to 24 bit/96kHz and signal-to-noise-ratio of 120dB. Output power for single-ended is 71mW @ 32Ω on high gain or 91mW @ 32Ω in Dual DAC mode. With the 2.5mm balanced jack, the output is 160mW @ 32Ω.
Bluetooth is facilitated by the Qualcomm CSR8675 which continues to impress me with its stability and low latency.
USB DAC Functionality
Just plug and play, it couldn’t be any simpler. UP4 works with Windows and Mac OS without the need of any additional drivers. Using any USB Type-C cable, UP4 is instantly recognized and ready to go.
Battery Life and Connectivity
The 550 mAh battery is good for up to 15 hours single-ended or 10 hours balanced. With its deep standby function, UP4 saves power when not in use and can stay in standby for up to an extraordinary 300 hours.
Pairing the Shanling UP4 is super easy and the connection is rock-solid in terms of stability. I have not experienced any cutouts or drops during my entire time using the device. Leaving my DAP or phone source on my desktop, I can pretty much walk around my entire house without losing the signal. Also worth noting is that the UP4 supports NFC which makes connecting your device even easier.
For testing, I used the UP4 both as a Bluetooth receiver and as an external USB DAC. Note that when connected to a computer via USB, the UP4 is limited to 16bits / 48kbps.
When testing Shanling products I usually mention their ‘house sound’: not only because it fits my personal preference but also because it’s fairly consistent across Shanling devices and even their ME500 PE earphones. The same can be said again of the UP4 and I wouldn’t have it any other way.
UP4’s sound starts with a neutral presentation and a hint of added warmth. Bass extension is great for a Bluetooth device – it really doesn’t feel like there’s anything missing at all. Not only does the bass have the proper extension, but it also maintains bass texture.
Mids get some of that additional warmth too and gain auxiliary body as a result. Clarity takes a very slight reduction in the process to provide that extra fullness but that can be a positive effect, especially with very resolving iems such as the NICEHCK NX7 Pro. In cases, like this, UP4 makes the sound less analytical and more musical. Vocals are emotive and lavish, the UP4 never sounds strained or erratic.
Highs are slightly softened but the extension is left intact, likely an effect of the extra body in the mids and bass. This is especially welcome on brighter headphones like the Beyerdynamic DT990 Pro. It’s also a tuning that makes sense for something designed with portability in mind. Once again, I’m impressed by the UP4’s naturalness as there are no noticeable artefacts or any artificial sound in the treble.
Perfect for any iems, the UP4 has a low impedance output and plenty of driving power. This makes it suitable for very sensitive iems as well as demanding ones such as the Tin Hifi P1. When it comes to headphones, the UP4 was able to drive planars like the Hifiman Sundara easily and even the Beyerdynamic DT990 Pro. Admittedly there was little headroom with the latter but in Dual DAC mode it sounded great and was able to push the headphones louder than I would ever listen to under normal circumstances.
Shanling UP2 Very similar in tonality but the UP4 sounds more effortless in its presentation. The additional output power is welcome for harder to drive headphones as well. To my ears, the UP4 has better staging and detail retrieval.
Earstudio ES100 This device set the early benchmark and is still a standard that new products are expected to rise up to. Some newer products like the FiiO BTR5 are starting to catch up in terms of app functionality which does a lot to even the playing field. Concerning audio quality, the ES100 sounds leaner and slightly less resolving than the UP4. Of course, you can customize the ES100 to sound more like it via the app but I feel the UP4 still has the upper hand in detail and staging.
If there is one thing that Shanling does well, it’s sound and the UP4 is no exception. This is a fantastic sounding Bluetooth amplifier that is perfect for playing music from your smartphone, whether it be FLAC files or streaming services such as Spotify and Tidal.
While it’s now pretty much a given for Bluetooth amps, the USB DAC functionality is a bonus too. Although it is currently lacking app support, I love its simplicity and the way it consistently just works. As expected, the design and build quality are great and overall, the UP4 is an easy recommendation for anyone looking for a Bluetooth receiver.