Recording - February 2018 - 52

Placid Audio
Carbonphone
RU-80
Reviews by Paul Vnuk Jr.
In an issue dedicated to capturing vocals, one might expect to
find reviews of microphones that are smooth, hi-fi, and pristine.
We do have a fair number of those, but the next microphone we
are looking at is all about unique lo-fi character. It's based on
the most ancient of microphone technologies, the humble carbon
element.
Invented in 1870 for the first telephone, the carbon mic
makes use of a pair of discs with loose carbon granules sandwiched in between. These carbon granules take very little
current to power; that's why they became the mic element
found in most original telephones from the 19th Century right
through to the 1980s. It's also why we often associate carbon
mics with the "telephone sound." Because they're nearly
indestructible, carbon elements are still in use today in military
and industrial applications, and that's where Placid Audio's
Mark Pirro sources his elements for his Carbonphones.

Cold war, hot mics

The RU-80 is the second Carbonphone in Placid Audio's
lineup. Mike Metlay looked at the original model, along with
its 5-position external Tone Box, in our February 2016 issue.
He described it as the perfect mic for "recreating hundredyear-old radio shows."
Sonically the Carbonphone is a distant, thinnish, distorted,
sibilantly spitty and largely unpredictable mic. In other words,
it's perfect for lo-fi vocals, drums, and instruments with a healthy
dose of edge. Its included phantom-powered Tone Box allows
you to further tweak and tune the mic with preset EQ filters to
suit your taste and mix. I love my Carbonphone; Mike let me try
it after the review and I ended up trading him my Copperphone
Mini for it! (It's a Placid thing; if you own these mics, you'll get it.)
The element in the original Carbonphone is from a US battle tank intercom mic. By contrast, the new RU-80 is made from
1970s Cold War era Soviet military components. The body of the
RU-80 is made from a pair of lacquered copper endcaps from the
company's Copperphone/Resonator models. It is shorter and wider than the original model, and retains its predecessor's aluminum
swivel yoke and rear-mounted Switchcraft XLR connector.
The cardioid RU-80 features a transformer-balanced output
using the same Hammond transformer found in the original
Carbonphone. All carbon mics, old and new, require voltage;
52

RECORDING February 2018

$285; www.placidaudio.com

the RU-80 does use +48V phantom power. While it doesn't
come with-or need-a Tone Box of its own, it will work just
fine with one if you already own the previous model.

Carbonostalgia

Sonically the RU-80 retains all of the above sonic anomalies
of the original Carbonphone, yet it is noticeably darker, richer,
and less bright and tizzy, with a 50 Hz-10 kHz frequency
response. Mark Pirro explained to me that the RU-80 is a tad
truer to a vintage carbon mic; it's fuller in bandwidth than the
original Carbonphone, which he deliberately band-limited in
its circuit design to produce its lowered fidelity and unique
interaction with the Tone Box. This makes the two Carbonphones different from one another and quite complementary.
On vocals, the RU-80 is great up close and personal. Despite
its distorted and rough-edged character, it's a mic that a singer
can really play to. Unlike using singer distance and level to
control proximity effect and intimacy on a "normal" mic, here
you work the mic to control tone, feel and grit. Long crooner-style
sustained notes can be thick and smooth, and distortion is
caused by fast transient bursts and sibilant sounds (as Mike
noted in his review of the Carbonphone).
On instruments at a distance, this transient breakup is a
neat effect on bright sources like hi-hat, tambourine, brass
stabs, and jangly guitar strings. On low sustained tones like
bass cabinet, keyboards through an amp, cello, and even
violin, the tone is more rich and gravelly.

RU ready?

The RU-80 is Placid Audio's lowest-toned and grungiest
model yet, and I say that with love. It offers a great flavor that
lives nicely alongside the original model, and adds a great
X-factor to any song, either blended with other Placid Audio
models or with traditional mics. Think of it as an overdrive
tool that does not require an effects box or computer process!

http://www.placidaudio.com

Table of Contents for the Digital Edition of Recording - February 2018