Line Out Test.
With a flip of a switch, you can enable 3.5mm LO output to bypass internal amp and provide the output of the DAC for an external amp connection. When switching to LO mode, the status LED turns from green to blue, a good visual indicator since the switch is in the back. For this test, I was using Asura 3.0FE with Romi Audio BX2 and Cayin C9 portable amplifiers. My Win10 laptop was used as a source playing a selection of test tracks.
Megatron LO output is around 1V, while typically I see DAPs with either a fixed 2V single ended LO output or a variable one that can go up to 2V for SE (and 4V for BAL). But 1V should be fine as well. The main idea here is to use a clean LO with an external amp to boost the output, to add a different coloring, and to provide volume control, if available. Also, in the below test, I compared PO output of Mega vs its LO with external amp.
Megatron vs Mega+BX2 – The direct sound from Mega had more transparency in mids, including more clarity and higher resolution. Adding BX2 to the Line Out made the sound warmer and thicker in mids. Typically, BX2 is a transparent amp without much coloring, which suggests a warmer tonality of ES9018K2M DAC.
Megatron vs Mega+C9 – Here, the sound got even warmer which I found to be a bit of an overkill, especially with Asura 3.0FE. Of course, it will be up to a personal preference, but I was happy to go back to Megatron PO output without a need for external amp.
BONUS: VE Monk SM.
Along with Asura 3.0FE, I also received Monk SM slim-metal edition. This new Monk version with 16.4mm DD, 32ohm impedance, and 115dB sensitivity, also features a new slim metal PK-style shell but in a different shiny chrome finish. And for $20, the price of Monk SM, you can also pick 4.4mm balanced termination, or go with 2.5mm or 3.5mm. Mine review sample came with a chrome finish 4.4mm plug to match the shells, a very nice touch.
Due to its “normal” 32ohm impedance, I preferred not to use it with Megatron because of a noticeable hissing since Mega is intended for higher impedance earphones/headphones. But I was still curious to hear how Monk OG compares to Monk SM, and decided to use L&P W2 usb dac/amp dongle since it has a more revealing tuning which helps to pick up details in comparison. Didn’t know what to expect, and actually end up with a pleasant surprise.
Monk OG vs Monk SM – SM has a wider soundstage with a much better imaging, quite noticeable how the sound spreads wider and has a more accurate positioning of instruments and vocals in space. In a relative comparison, the OG Monk sound was a bit congested. Also, SM has a deeper sub-bass rumble, a faster mid-bass punch (faster attack of the sound), and a crisper and airier treble (better treble extension). While not exactly night and day, these changes were actually noticeable. I’m getting a much better fit with SM version, so I don’t discount that it could be a big contributing factor to sound improvements.
In my testing of this $50 Megatron USB dac/amp, I compared it to a handful of other hi-end dongles that cost 5x as much and can’t match its performance (especially in bass) when paired up with more demanding earbuds. Does this make Megatron a better choice in comparison to other premium dongles? It will all depend on the pair up. Megatron is not your typical compact USB dac/amp, there is no display or buttons or other fancy features, and it’s not designed to be used with your average impedance higher sensitivity IEMs, earbuds, or headphones.
The performance of this Mega-dongle stands out while being able to drive higher impedance earbuds and headphones to their full potential, something which other hi-end dongles are not fully capable of. And despite its higher output power driving capability, it still draws about 120-130mA of current from a host (per my measurements), on par with other less powerful devices, making it friendly with smartphones. Plus, its bridge-charging capability is very useful for smartphones and laptops, making sure you can charge the host while using Megatron.
In pair ups I tried, Megatron delivered a solid performance with a neutral balanced signature and a natural musical tonality. It does have a more neutral/musical rather than technical performance, and certainly, it will not replace your kilobuck DAPs. After all, you have to be realistic since we are talking about $50 device. But its price/performance ratio is very impressive, and it pairs up quite well with both more revealing and naturally tuned earbuds. Especially if you are a fan of higher impedance VE earbuds and their house tuning, it makes a perfect combo!