TOPPING L70 Amp: Closer Examination

As with any matching amplifier meant to be stacked with the simultaneously-released DAC, the TOPPING L70 follows the exact same design language down to the use of the same external CNC-machined aluminium alloy chassis at 200 x 138 x 44 mm and comes in the same black or silver color options to better pair with the E70/E70V. The longer length here did initially make me question whether TOPPING would have a lot of blank room on the front and then I was pleasantly surprised to see a dedicated display here too! There's the customary Hi-Res Audio badge visible here and then most of the same follows from the previous page including the company logo and product name, a capacitive button on the left of the display, an IR receiver port to the right, and then we get the three headphone outputs including full-size 4-pin balanced XLR, 4.4 mm balanced TRRS, and 6.35 mm (1/4") single-ended TRS connections. There is a matching volume knob at the end which has a red accent ring on this black color version.


Things get busy on the back though, which makes sense given the TOPPING L70 is not a beginner's amplifier necessarily. On the left is a set of two combo input ports offering both 3-pin XLR and 1/4" TRS balanced input from a compatible source, including the E70/E70V with the dual XLR outputs we saw on the previous page. You can also use the L70 as a preamp and thus we get dual 3-pin XLR output too. These are accompanied by matching sets of RCA input and output connectors and then we see the same 12 V trigger as on the E70/E70V DACs. There's a Type-C port for any firmware updates for the L70 itself, which is nice to see for those looking for a longer-term solution, as well as a handy toggle for helping eliminate any ground loop noise—set it to GND in normal use and Lift if you experience said noise. Rounding off the back panel is another of the same 3-prong power cable inputs and the associated on/off switch itself. The sticker on the bottom confirms the amplifier is rated for as much as 80 W in, although in practice I did not see it take any more than 25 W in regular use and well below that most of the time.


Disassembly of the TOPPING L70 is achieved in a similar manner as the E70/E70V DACs before and was done after all testing was finished until the same end point. This point too we see a very similar low noise integrated power supply in use and then the relevant section is for the amplification stage itself where TOPPING uses the same NFCA (nested feedback composite amplifier) design as from its high-end A90 amplifier. Note that this not the same as what is on the newer A90 Discrete, which may be why the L70 was able to use the same design as the older A90. It provides for both voltage and current amplification, a gain feedback technology, and a fully balanced amplification circuit which comes together to allow for ultra-low output impedance on the headphone outputs, high current drive mode as needed, and a low operating noise floor itself. There's a large heatsink on top of the NFCA modules and then we see an R-2R volume control system using relays and resistors for precise, channel-matched volume control.