The E50 has several options that can be accessed through the menu which can be accessed through the touch button or the remote control. To access the menu system using the touch button, the device must initially be unplugged, and then press and hold the touch button while turning on the E50. Looking at the E50 DAC, it has what you would expect in terms of the available input options. At the rear, it has USB, coaxial, and Toslink inputs. The rear of the L50 has a pair of outputs, but they are just passthrough outputs. What’s more interesting with the L50 though is the firmware update port which is also located at the rear of the device. The L50 on the other hand pushes the envelope on what Topping can do with their NFCA technology in their midrange offerings. Although all of the amplifiers in Topping’s current lineup are based on NFCA technology, the implementation on the L50 is closely associated with the implementation done on the A30 Pro. Topping has been busy again with another release of compact desktop amps and DACs. This time they are focusing on the range just below their headline D and A series DACs and amps such as the A90 with the launch of the new E50 DSD512 and MQA capable balanced DAC as well as their new L50 balanced headphone amplifier.

Once the device is initialized, the screen will either show the output level if the E50 is in pre mode and the sampling rate if the E50 is in DAC mode. The touch button can only be used for input selection and holding it would put the E50 into standby mode. However, menu access can only be done using the dedicated buttons that are on the remote control. ES9068 is a current output DAC chip, meaning that a current to voltage conversion (I/V) stage needs to be built around it. Thankfully, Topping went with smooth and natural sounding OPA1612 op-amps, instead of LME op-amps that were sitting in their older devices. OPA’s are better suited for ESS implementations and is seems that Topping is already going on the right path. I’m glad that Topping used all 4 channels of this particular DAC chip, meaning that E50 is indeed a true balanced DAC. Imaging/Soundstage​I usually say staging and Imaging are more headphone dependent. This is very much the case here. I heard no added benefit to the stage or imaging. I usually like when an amp adds a little of its own flavor for staging but I just couldn’t tell a difference like I do with the main competitor from S.M.S.L. The L50 is equipped with three gain settings of -14.3dB/-0.1dB/13.9dB. A wide range of gain settings lets the L50 easily adapt to all types of headphones from extremely sensitive IEMs to the most power hungry over-ear headphones.Headphone Amps: Flux Lab Acoustics Volot, Benchmark HPA4, Burson Soloist 3X, Musician Andromeda, SMSL SP400, Topping A90, L50, Soncoz SGA1, Gustard H16 When shutting down, the input signal is directly output to RCA or TRS without amplification, which will be more suitable for working with active speakers/monitor speakers when the DAC has pre-amp function. Sound(overall)​These final impressions were done off the E50 attached to the L50 via RCA. This will be what the E50/L50 sounded like with all the headphones I used. Things like headphone pairings will produce different results and impressions vs what my ears hear on my specific gear. Accessories and unboxing​For the L50 box we get the box, a nice protective sleeve covering the unit and then a giant wall wart or powering the L50. The E50 comes the same way as the L50 but we get a USB cable and USB power cable. Fairly straight forward. I would have liked to see a cheap set of TRS cables included with either unit since I don’t know of any DACs or amps using TRS quarter inch cables to do a balanced connection.

When shut off, the L50 automatically outputs the signal to RCA or TRS without amplification, so you can keep the L50 in your audio chain even while using active speakers and/or a DAC’s preamp function. There are many combinations here to test so I limited the input to balanced but measured both balanced and unbalanced headphone output. Let's start with balanced input: With a small footprint and a 30dB gain range, the TOPPING L50 is a desktop amp that fits practically anywhere and powers just about anything. Redesigned new NFCA circuit based on the same working principle as the one in A30 Pro, It provides 2x the power at 300 Ohm compared to L30. The new circuit shares the same 0.3uV ultra low noise and 145dB dynamic range as well as 0.00006% THD+N.This will go into the menu, and touching and holding it will either advance the menu or make a selection within the menu. The menu itself is made mostly of symbols, so those who are uninitiated will have a hard time deciphering the alpha-numeric code in Topping’s DACs. Instead of the usual switching power supply we now have a beefy AC transformer. As I have noted before, AC input makes it easier to generate positive and negative rails for the amplifier so I can see the motivation. Then again, the transformer is inefficient and quite large.

All in all, both units are covering our hearing range in full, extending from the bottom-end to the highest treble peaks, never adding or subtracting anything from the mix. A common trait that the L50 shares with the E50 is that its midrange presentation leans towards a more honest presentation. This means that male vocals aren’t artificially induced with euphony, so the natural timbre of the voices of crooners such as Michael Buble or Josh Groban easily comes through. Comparatively, female vocals are drier giving them a less wispy quality than expected. The main business of a headphone amp is producing power though to drive more difficult headphones. So let's test that with 300 ohm load:

IEM pairing opinions​

The E50 comes equipped with the Topping’s iconic LED display with the orange font. The display layout is quite simple. You see the volume level, sample type and rate, active input, and output. Furthermore, the E50 does not have a volume pot or any means of navigation, you only get a touch-sensitive, multifunctional button which is located on the front panel, next to the LED display. This multifunctional button supports tap and hold actions but does not let you access the complete menu without entering the ”setup menu”. You will have to press and hold the power touch button while the device is in standby mode to access this menu. I must say that without the remote, it is quite hard to navigate, select and apply individual settings so I recommend you to use the remote controller instead. I appreciate the effort that Topping has put to offer us a way to control the device with only a button without the remote though.