Test: sE Electronics DM2 “T.N.T.” inline microphone pre-amp

The sE Electronics DM2 T.N.T. inline pre-amp lets you choose between a moderate +15dB or generous +30dB of gain with an ultra-high impedance input and eight load settings to match any passive microphone. It suits all your dynamic mics like the V7 and your passive ribbon microphones, and it’s perfect for podcasting, recording, live sound, etc. I had the pleasure of reviewing the DM1 Dynamite when it came out and that one still is a winner, so I had high expectations for the DM2.

The box sE Electronics chose to present the DM2 T.N.T. in has the same form factor as the DM1: a tube that resembles a dynamite stick. There is one surprise inside that wasn’t in the DM1 box: besides the DM2 itself, its user guide and a sticker, you will find a tiny screwdriver to handle the gain and impedance switches. It’s a minor detail, but a nice one, as not every user will have a screwdriver with a fitting head readily available.

The MD2 T.N.T. uses Class-A designed — specially selected high-grade, according to sE Electronics — FETs with a low output impedance of 135 Ω and very little noise compared to anything else on the market. Additionally, the gain provided is always consistent regardless of the connected load, thanks to the DM2’s eight switchable impedance settings and the dedicated buffer amplifiers. The device runs on phantom power supplied via the gold-plated XLR connector, without transmitting that power to the mic.

Even more so than the original DM1 Dynamite, the T.N.T. stick will appeal to anyone from the lonely podcaster to the high-profile recording engineer and stage performer. And here’s why: the DM2 boosts the signal from a passive mic without adding audible noise or colouration, as well as potentially opening up your mic’s bandwidth capabilities with the impedance switch.

A V7 without the DM2 and set at the same level as my tests, recording under exactly the same circumstances, has a noise level of about -65dB.

Noise with the sE Electronics DM2 TNT

The DM2 T.N.T. does add some noise, but at +15dB, in a silent, treated room it never got higher than -52dB at 20Hz and around -58dB starting at 100Hz. At 200Hz, the noise was around -74dB. These tests were run at impedance levels of 2K7 Ω and 100K Ω.

Noise with the sE Electronics DM2 TNT

The gain boost of +30dB adds more noise, especially with higher impedance levels. At 2K7 Ω, the noise floor rose to around -40dB dB at 20Hz, dropping to -64dB at 200Hz. At 100K Ω, there was no change at 20Hz but a higher level at 200Hz of around -42dB.

When I set the higher impedance, however, detail in both the lows and highs seemed to be picked up as well. Yet higher impedance levels only added hiss with the V7 in my tests, but perhaps some ribbon mics might open up even more.

The added noise can be filtered out, as it is uniform. Provided you start your recording with some 10-20 seconds of silence, you can easily filter it out completely with RX9 Advanced’s spectral noise module that is now available as an ARA plugin for your DAW, or with RX9 Advanced’s improved Dialogue Isolate.

Just as the DM1, the DM2 has a thick metal cylinder design that can stand mic abuse and, if the DM1 is anything to go by, the DM2 will operate for years without hiccups. The unit should be mounted as close to the mic as possible, so you’ll almost always see sE Electronics picturing it inserted directly into a V7’s XLR connector. The small wiggle room it allows for doesn’t matter with the sturdy V7 but is a good thing if you use it with a budget microphone. Those are perhaps not as robust and wiggling is better than breaking or buckling a mic’s connection point.

The DM2 T.N.T. inline pre-amp retails for around 150 EUR.

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