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Gauge ECM‑87 Virtual Mic Locker Kit

Microphone Modelling System By Paul White
Published May 2024

Gauge’s affordable ECM‑87 has a virtual dimension.

Gauge ECM‑87 Virtual Mic Locker KitGauge are a US‑based microphone manufacturer whose products are hand‑soldered in the USA using parts from China, Japan and Germany. Assembly is followed by an intensive QC stage, also in the USA, before shipping. We looked at their valve ECM‑47 back in SOS December 2022, and here we’re reviewing the solid‑state, transformerless ECM‑87. Both are large‑diaphragm capacitor microphones loosely based on vintage German designs, but the ECM‑87 model has a twist: it can be used with Gauge’s Mic Clone plug‑in to emulate a range of other classic microphones.

Starting with the mic itself, which is available on its own or as part of the Mic Locker Kit bundle, the ECM‑87 features a very Neumann‑esque outline and is built around a one‑inch, cardioid‑pattern capsule skinned with six‑micron‑thick membrane material. Its specifications are comparable to those of other similar microphones, and include a sensitivity of 12.5mV/Pa, a maximum SPL of 128dB at 1kHz and an equivalent noise level of 17dB (A‑weighted). A standard 48V phantom power source is required for use.

Unscrewing the base ring allows the satin chrome body sleeve to be removed, showing two neat circuit boards populated with full‑sized rather than surface‑mount components. A switch on one of the circuit boards activates a low‑cut filter. While this is less convenient than a switch mounted on the mic body, the low cut can usually be left engaged if the mic is being used for vocal recording or instruments that don’t project a lot of low end. The data sheet that comes with the mic suggests that it can be used to record just about any instrument in addition to the human voice.

All the metal parts, other than the body sleeve, have a bright chrome finish. The mic comes with a soft storage pouch and a metal‑framed, elasticated shockmount.

Let’s Talk About Specs

While the quoted 20Hz‑20kHz frequency response figure doesn’t tell us anything particularly useful without any limits being specified, the response plot is more revealing. In essence, the mic is nominally flat up to around 2kHz, with no LF roll‑off apparent before the graph stops at 20Hz. Above 2kHz the response rises to a first presence peak at 4.5kHz before dropping back between 6 and 7 kHz, then it climbs again to a second peak at around 12kHz. The lower peak extends to 4dB above nominal while the higher peak maxes out at around +6dB. This is somewhat different from the response of its European inspiration, which is much flatter in the presence region.

Moving onto the software component, the Gauge Mic Clone plug‑in comes in AU, VST2/3 and AAX formats for macOS and Windows, and was developed by Gauge’s Dr Chandler Bridges and his research team, in collaboration with Final Mix Software.

The Mic Clone plug‑in offers a range of classic microphone emulations.The Mic Clone plug‑in offers a range of classic microphone emulations.

As far as I can tell, the Mic Clone plug‑in works on the ‘match EQ’ principle, modifying the output of the ECM‑87 to present the same frequency responses as a range of classic mics. This is not the first time a company have come up with a way of making one mic sound like another, but it is one of the most affordable examples. The plug‑in is authorised using an iLok account, but there is a seven‑day free trial. You can also buy the mic and software as a bundle.

The classic mics modelled are the Neumann M49, U87, U67, U47 and U47 FET, AKG’s C12 and C414, and the Sony C800G — a good cross‑section of go‑to studio mics. Essentially the plug‑in applies an EQ curve that is the difference between the response of the ECM‑87 and the target microphone. A fader allows the sound to be morphed gradually from unprocessed to processed, so you can also explore the inbetween sounds. The mics are fully tone matched at the fader’s mid point: go further, and you get into ‘nothing succeeds like excess’ territory. This approach to tone matching has the limitation that it can only work correctly for on‑axis sounds. No information is provided as to whether the plug‑in replicates any of the target mic’s saturation characteristics, which would be relevant in the case of valve microphones.

As the Mic Clone plug‑in takes the ECM‑87’s frequency response as its reference point, it won’t produce the correct effect with other microphones, though you may still get interesting and usable results. However, Gauge also offer a similar plug‑in called Mic Locker, which is designed to to coax alternative tonalities out of any microphone.

The great thing about ECM‑87 Mic Clone is that it allows you to experiment with different microphones after recording.

Model Behaviour

Not having access to the mouthwatering selection of classic mics emulated by the ECM‑87 Mic Clone package, I had to evaluate the sounds of the mics on a purely subjective level. Starting with the M49, this setting pulls back some of the presence of the raw ECM‑87 sound so may be a good choice for those with naturally sibilant vocals, while the U87 model flattens out the response to some extent, making for a natural balance. The U67 is similar, with perhaps a hint more clarity and a solid sense of tonal weight, while refraining from sounding aggressive in the highs. This was my favourite setting for male voices that needed help in the lower mids, and it also works well on electric guitar. The U47 adds warmth, while the 47 FET keeps the weight but also captures transient detail well. The C12 is a real classic, and this emulation sounds transparent and lively without being too cloudy at the low end. I have a C12 VR (admittedly not quite the same thing as a C12), and this C12 emulation has something of the same low‑midrange lightness that my mic exhibits. I’d describe the sound as open, with smooth highs, but not at all weighty. AKG C414s come in various flavours, but the model offered here has a voicing similar to that of the C12, with a very open high end.

Depending on the sound source, the differences between Mic Clone settings can be quite subtle, but I’d suggest that rather than obsess about replicating a particular mic’s sound, you simply try all the options to see what sounds best with the voice or instrument you have recorded. It is often the finer details in the response curve of a microphone that either flatter a voice (or instrument) by emphasising what sounds good about it or, in some cases, what is less desirable, in which case it is time to move on to another mic model!

The great thing about ECM‑87 Mic Clone is that it allows you to experiment with different microphones after the fact. The Gauge ECM‑87 is a very capable mic in its own right, the Mic Clone software really extends its usefulness — and the whole package is very affordable.


The idea of pairing a microphone with software to allow it to emulate other models isn’t new, but the competition tends to be rather more expensive than this Gauge example. Alternatives include the Universal Audio SC‑1, Antelope Audio’s Edge range and, of course, the Slate VMS.


  • A very capable large‑diaphragm mic.
  • The optional Mic Clone software is tailored to the ECM‑87’s response for emulating other mic models.
  • Shockmount and storage pouch included.


  • Low‑cut filter switch is inside the mic body.


While there are countless Chinese‑built microphones in this price range, the Gauge ECM‑87 gives a good account of itself and has the advantage that it can be used with the Mic Clone software to give it a range of classic voices.


£299 including VAT.

$399 (discounted to $349 when going to press).

Gauge +1 855 424 2843.