Alctron VS Warm Audio 251 Clone Shootout

A few years ago at NAMM, I briefly tested a few of Alctron’s microphones on my voice, and the T190 stood out as my favorite sounding in the bunch. Though the environment was a noisy convention floor, the mic really sounded warm, smooth, and not too bright or too dull. I had Alctron send me one to test further in the studio. I came to the conclusion that it was an amazing mic worthy to become the first microphone since 2007 to bear the N-SONIC name, rebranding it as the N-SONIC NS-251. They have nearly sold out at this point, but I have ordered some of the Alctron version which can be purchased here while I’m waiting for more of the N-SONIC version to be manufactured.

Not long after releasing my N-SONIC mic, Warm Audio came out with their take on a 251 clone. Given that their mic is the only other 251 clone under $1000 that I am aware of, I wanted to find out how their twice-the-price mic compares. I may be biased, but honestly I was so blown away that I think the price tags should be swapped! You’ll have the opportunity to come to your own conclusion on which mic sounds better in the blind shootout I’ll link below, but first I am going to tell you about the other reasons I like the N-SONIC NS-251/Alctron T190 better than Warm’s version.

Upon unboxing the two tube mics, I Immediately noticed the first win for N-SONIC! The Warm Audio WA-251 comes in a glossy cardboard box with some nice graphic design. The N-SONIC NS-251 trades that in for a much sleeker aluminum locking case. Both brands have a big hunk of foam on the inside of their respective boxes with cutouts that keep everything securely in place. Admittedly, the quality of foam used in Warm’s cardboard box feels a little nicer than the foam in N-SONIC’s fancy aluminum case, but if you want an aluminum case at all for your Warm Audio mic, you’ll have to dish out an extra $99 on top of the already twice-the-price mic.  

Both microphones come with beautiful wooden boxes for the actual mic body, but Warm’s feels very lightweight and cheap. It does seem to have slightly better hinges though, and a nice looking emblem on the front of the box. Upon closer inspection, the emblem is just a little rubber dome sticker though. Warm’s box comes in a cherry finish while N-SONIC’s is a more natural wood finish. Both boxes are lined with black, velvet-covered foam.

The microphone bodies are a little bit different from each other in that the N-SONIC one is a bit shorter in length than Warm’s. The other exterior parts are identical. I would have to assume that at least some of the parts to both mics are made in the same factory. Upon opening them up, I found the tube in the Warm mic is a JJ 12AY7 and the N-SONIC has some generic 7025A. The Warm also boasts a Cinemag transformer. The mics’ internal circuitry do not look very similar, but I’m not technical enough to comment on which one is more true to the original design.


The shock mounts are both very nice and sturdy—almost identical besides the Warm one being black instead of silver. I think the silver N-SONIC one goes better with the cream color of these mics though, and upon securing the latches, I found the N-SONIC one to be much easier to use. The Warm one has shorter latches, so there is less leverage, and you also have to hook before latching instead of simply latching it tight. The Warm’s latch is also in an awkward location relative to the elastics, and you have to move the elastic out of the way. This seems like it would raise the risk of dropping it if you aren’t careful, but both shock mounts do hold their mics very securely once latched properly.

The power supplies are nearly identical inside. I am pretty certain they are from the same factory as well. The most obvious difference is the paint job. The N-SONIC one has the same glossy cream paint from the mic body, while the Warm uses a flat black paint. The other big difference is that the N-SONIC has nine polar patterns, instead of the three on the Warm mic (cardioid, figure 8, and omni). Upon powering up, I also noticed the LED on the Warm power supply is bright blue, and the one on the N-SONIC is a more vintage-looking faded blue, which I really think looks nice. On the inside of the power supplies, everything looks pretty much the same besides a couple of wires going to the polar pattern switch, and some of the capacitors being green instead of black in the N-SONIC. The circuit board, transformer, resistors, and other components are exactly the same inside.

Another plus for the N-SONIC is that it comes with a very nice pop filter that attaches to your mic grill via elastic bands. With the Warm mic, you’ll have to dish out even more cash if you don’t already have a pop filter.

Now, we get to the most important part—the sound—but I’ll spare you most of the details since you can just download the files below and decide for yourself. What I can say is that I was quite impressed with the noise levels on both mics. They are very low noise for tube mics, and there is no perceptible difference in the noise floor to me. I found that on some sources, the mics sounded very similar, and on others, there were more pronounced differences. 

I think the N-SONIC is a clear winner in price, sound quality, and presentation. For only half the price of the Warm, you get a mic that includes about $130 worth of extras and sounds every bit as good! You don’t have to take my word for it, though. Check out the blind shootout below, and decide for yourself!

About the blind test:

In this shootout, I compare these two microphones plus one additional. I don’t have access to a real 251 or even any of the more expensive clones, but I do own one of those nifty emulation microphones that claims to sound indistinguishable from the real thing, so I thought it might help to include it in the shootout. For each source, all three mic capsules were placed close together and pointed at the source on axis. There are two guitars, tambourine, mono drum overhead, lead vocal, and background vocal. Additionally, there is a bass DI track and some close drum mics you can blend in if you’d like, but these ones were not recorded through the mics we are comparing. The 251 emulation plugin has been bounced to the tracks that were recorded with that mic. The tracks are labeled with A, B, and C in the titles, each one representing one of the three mic models. All tracks have been level matched by RMS normalization. Click here to start!

If you are opening the Pro Tools session:

The tracks are grouped together by mic, so you can solo the full mix for each mic if you want, or just disable the groups to compare the individual stems.

If you are using another DAW:

Simply copy the audio files from the audio folder into a new session. They should all match up.

The song is called Sweet Poison and is an original by my sister, Melinda Molenda. Additional credit is due to Rick Bickerstaff for laying down the drum track.

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