RØDE NTK Tube Microphone

One of the few things about recording that hasn't changed in the past decade is that you still need great microphones to make great recordings. Great

One of the few things about recording that hasn't changed in the past decade is that you still need great microphones to make great recordings. Great mics often make the difference between compelling, sonically superior tracks and inferior or uninteresting ones. That is especially true when recording that most elusive of instruments, the human voice. But there's a catch: great microphones tend be expensive.

Thankfully, one thing about recording that has changed in the past decade is the ratio of price to quality in studio gear. The trend is lower prices for better (or at least comparable) quality, and large-diaphragm studio condenser mics have been at the forefront. But are any of those affordable microphones really as good as the more expensive ones? Perhaps. One thing's for sure: not all of them are.

Røde Microphones' latest creation is the NTK, an affordable large-diaphragm tube mic with Class A tube circuitry and a fixed cardioid polar pattern. The NTK ships in a cardboard carrying case with a power supply, a 30-foot cable for connecting the power supply to the mic, and the M2 standmount. The mic comes ensconced in a padded vinyl zipper pouch. The SM2 shockmount ($99) is optional.


Nothing about the NTK is flimsy. The components — mic, power supply, and cable — are sturdily constructed and appear to be built to last. The microphone is heavy; when using a boom, I had to weight the base of a tripod mic stand to prevent it from tipping over. It's evidently rugged, too: I accidentally clobbered my forehead with the mic while positioning it on a stand. No harm came to the NTK, but it did leave a nice bump above my eye.

The NTK looks great. The mic's cylindrical body and grille basket boast a satin-nickel finish reminiscent of classic microphones from the past. An inset brass dot just below the grille — a Røde signature — identifies the capsule's address side.

Attaching the microphone to the M2 standmount is easy and foolproof: simply unscrew a sturdy plate at the base of the mic, insert the mic base through the mount, and screw the plate back on. The mic couples to the optional shockmount in the same manner. Either mount holds the NTK firmly in position.

The microphone connects to the external power supply through a proprietary 7-pin cable rather than a standard 3-pin XLR cable. Many other tube mics also employ special cables, so that's nothing new. However, care must be taken not to damage or lose the 7-pin cable, or the mic will not be operational. (Røde claims quick turnaround in the event that you need an additional cable.)

A cool blue LED glows on the front of the NTK's power supply when the unit is on. The power supply can be externally toggled between 110V and 220V operation using a recessed switch, which supplies the necessary power to the mic and eliminates the need for phantom power. A slow-blow fuse resides inside the IEC power-connector socket. A standard 3-pin XLR connector provides signal output from the rear panel of the power supply.


Fine craftsmanship aside, it was the sound of the NTK that really got me going. I had my first opportunity to use the mic on recently signed Arista/Nashville recording artist Kristy Lee. I had produced Lee's original demos at my personal studio and used a Neumann KM 86 for her previous vocal tracks, pleasing everyone with the results. After her label signing, Lee came back to record a few of my songs for the label, and that happened to be during the week that a pair of NTKs arrived for review.

Experience has taught me that certain microphone and voice combinations work well and that others don't, no matter how good the voice or the mic. The best thing is to try out combinations of mics and preamps until you find a signal chain that best complements the vocalist. I already knew the KM 86 flattered Lee's voice, so before the session started, I set up the KM 86, a Neumann TLM 103, and one NTK. I ran the three mics through the same signal chain: a Neve 1272 preamp into an Empirical Labs Distressor (set to Opto mode) and from there into a Mark of the Unicorn (MOTU) 1296 audio interface.

I soon eliminated the TLM 103 — it didn't sound bad, just too neutral and polite. Although the TLM 103 sounded more up-front and personal than the KM 86, the KM 86 had more character. But when I tried the NTK, I knew after only two bars that it was the mic for the day. It had not only the up-front quality that I liked in the TLM 103 (both are large-diaphragm condensers) but also the personality of the KM 86.

Clearly, the NTK was designed to be musically pleasing rather than clinically accurate. It has a gentle presence boost from about 2 to 5 kHz and another slightly bigger boost centered at about 12 kHz. The boosts opened up the sound at exactly the right places to complement Lee's voice. In fact, Lee likes the vocal tracks so much that she wants the label to use them for the final record.


I really like the NTK's personality. The mic is not linear in its response; rather, the tonal color blossoms as the source gets louder. That makes the NTK sound just right for many sources, especially lead vocals. It also requires that you take more care with mic placement. The reward, though, is added tonal control.

For example, having the vocalist sing really loudly close to the mic will create a fuller and more aggressive sound than when you have the singer step back from the mic: the tone becomes more neutral as the vocalist backs away. Even with the levels matched, the two tracks will sound different — and not just because of bass boosting from the proximity effect. (The effect is roughly analogous to the difference in sound you get from turning down the volume knob on an electric guitar as opposed to turning down the amp.) On really loud, belting vocals, I preferred to keep the singer closer to the microphone to maintain that aggressive edge and then simply to back off the preamp. I loved that sound.


Although NTKs are not sold as matched pairs per se, Røde claims that any two NTKs will perform almost identically, thanks to tightly monitored quality control and the fact that the twin-triode 6922-model tubes are stringently hand-selected. That claim was borne out in my testing.

I'm presently producing tracks for a set of female twins called Coppola, and the NTKs worked well for their voices, too. I tried a Neumann U 47 and U 67 on them first, which sounded great; however, the tonal difference between those two mics was too drastic — the twins' voices are very similar in nature, and I wanted to preserve that element. As it turned out, I was just as pleased with the sound of the NTKs on their voices. For less than the price of one vintage tube mic, I had two tube mics that I liked just as well.

The twins record their vocals at the same time while standing next to each other. The NTKs are fixed in a cardioid pattern, so I needed to experiment to find the mic positions that afforded the best rejection and phase coherency. As I discovered, the NTK provides a good bit of off-axis rejection, especially at 90 and 270 degrees, so it's a viable option whenever side or rear rejection is important.

The NTK can take a lot of level, too. At one point, I thought I heard distortion in the NTKs — the twins can sing extremely loudly at times — but later I realized I was overdriving the preamps. Although the NTK does not offer an attenuation pad, Røde claims the mic can take levels as high as 158 dB, making it usable even for drum overheads and guitar amps. Later tests showed that to be true.

One potentially negative thing about the NTK is its tendency to accentuate sibilance from some sources. For example, the presence boost that worked so well on Lee's voice (and on other instruments) accentuated sibilance from the Coppola twins. Fortunately, I solved the problem easily with a deesser (I used Waves DeEsser plug-in). But in the end, the NTK's tonal character was well worth having to deal with a bit of sibilance.


Piano is my main instrument, so I was curious to check out the pair of NTKs on acoustic piano. The vaulted ceiling in my living room makes my Yamaha grand sound pretty darned good, so I set up the NTKs and tracked them through a MOTU 828 computer audio interface in to my PowerBook at 24-bit resolution.

The resulting tracks sounded excellent. Again, the NTKs' frequency boosts gave the piano a finished sound that didn't scream for EQ after the fact. The overall sound was big, but even the low-level material sounded great. The NTK is quiet, particularly for a tube microphone, so you can crank up the preamp to capture low-level material yet still acquire a clean, rich signal.


The NTK also sounded good on acoustic steel-string guitar. The tone wasn't particularly pure, though, meaning the NTK is probably better suited for rock tracks than, say, clean bluegrass guitar tones. The NTK nicely enhanced the aggressive edge of a hard-strummed part I recorded, providing a dose of attitude that fit the track well.

The pair of NTKs also worked well on a solo nylon-string guitar recorded in stereo. Again, the sound was not as pure as that provided by some mics. But the NTK's quietness lets you get a tube sound on tender acoustic-guitar passages, without the usual accompanying noise.

I also tested the NTK on triangle, tambourine, and egg shaker. Large-diaphragm tube condenser mics are typically not ideal for high-pitched percussion, and the NTK is no exception. Actually, the egg-shaker track didn't sound bad, but the tambourine and triangle tracks exhibited some distorted upper harmonics, resulting in an unfocused yet edgy sound that I didn't care for. That is not necessarily a deficiency on the NTK's part, but a reminder that it, like most mics, is not the perfect choice for every sound source.


Although the old maxim “You get what you pay for” generally holds true, occasionally a product comes along that gives you more than you expect for your dollars. The Røde NTK large-diaphragm tube condenser mic is such a product. Despite being priced at less than a grand, the NTK will put you on equal footing, or better, with many new and vintage microphones that cost several times as much.

I love the NTK. Like the best of tube microphones, it has a sound — call it character, attitude, or what have you — that is musical to the ears. The mic's gentle presence boost makes just about everything sound good, especially vocals, and the tone really blossoms as you hit the capsule with more level. The NTK not only sounds great but also is quiet and can handle a lot of level. Moreover, the NTK is clearly built to withstand a lot of use. My guess is that it will still sound great 40 years from now.


Røde Microphones
large-diaphragm tube condenser mic



PROS: Big rich sound on a range of sources. Excellent on vocals and piano. Quiet. Sturdy. High SPL handling. Beefy power supply with selectable 110V or 220V operation.

CONS: Presence boost can accentuate sibilance on some sources. No attenuation pad or highpass filter. Comes in cardboard box.


Røde Microphones
tel. (310) 325-4444 or 61-287-659-333
e-mail info@rodemicrophones.com
Web www.rodemicrophones.com

NTK Specifications Acoustic Operating Principlepressure-gradient transducerDiaphragm1", 6-micron-thick gold-vapor-deposited MylarTubetwin-triode 6922Polar Patterncardioid (fixed)Frequency Response20 Hz — 20 kHz (±6 dB)Dynamic Range>147 dBA (for THD <1%)Signal-to-Noise Ratio>82 dBASelf-Noise<12 dBAMaximum SPL>158 dB (for 5% THD @ 1 kHz)Dimensions8.50" (H) × 2.28" (D)Weight1.68 lb.