Field Test: Sony C-38B Microphone


Sony's C-38B is certainly one of the oldest new mics around. The lineage of this latest version goes back to 1965, when Sony unveiled the successor to its famed C-37A tube mic. But the C-38 had one major difference from the C-37A, as the newcomer was the world's first Field Effects Transistor (FET) microphone. In 1969, the C-38 was updated as the model C-38A with a change in the windscreen design, and again in 1971 to the C-38B, which added phantom power (9-volt battery or external DC 24V to 48V). Now, after years of absence, it's back: At the Fall 2003 AES show in New York, Sony “reintroduced” the C-38B, even though more than 65,000 of these studio classics are in use today.

First released in 1965 as the C-38 FET, Sony's new C-38B is beautifully constructed of painted brass, weighs in at 23 ounces and features a large 1⅓-inch, six-micron-thick, gold-deposited Mylar diaphragm with brass back plane. With the same diameter and structure as the C-37A capsule, this is a true condenser capsule polarized with 100 volts. A steel mechanical shutter, operated through a small recessed hole on the back of the mic, changes the polar pattern from unidirectional to omnidirectional.

Also on the mic's backside is the on/off/low-cut selector rotary switch. Not looking like a switch at all, it is actually a knurled metal collar that surrounds the mic cable's entry into the C-38B body. There are five switch positions: off for conserving the internal battery; M for full-range response; and M1, V1 and V2 for bass roll-off starting at 40 Hz, 80 Hz and 160 Hz, respectively. All three roll-offs are 6dB/octave curves.


A slick pop-open door on the front of the mic allows you to insert a standard 9-volt (6F-22) battery, select the -8dB attenuator pad or engage the -6dB/octave 7kHz roll-off filter. Indicating the relative condition of the battery is a red light bulb visible at the bottom of the mic's body that flashes momentarily when you first turn on the mic.

The C-38B finishes with a gimbaled U-shaped mounting bracket that attaches to either side of the mic's body with two thumb-nuts. This feature resembles the C-37A or the venerable RCA DX-77 ribbon mic. The bracket terminates in a rubber shock-mount socket in a threaded base that has a strain relief for the 20-foot attached mic cable and XLR connector. There is no elastic suspension shock-mount available.


I always do my first general comparisons while talking directly into the mics and having my assistant switch between them on my cue. Compared to the Sony C-38B, a Soundelux U195 sounded less open and less “in your face”; the Sony was much more present. An AKG C 414 ULS had less top, bottom and lower midrange than the C-38B, while a Neumann U87 was thinner-sounding due to an upper mid-range boost as compared to the flatter C-38B. Only the much more expensive Neumann M149 tube beat the Sony in overall openness and bigness in sound.

Next, I used the C-38B on drums, bongos, vocals, acoustic guitar and then as a room mic. In all cases, the Sony performed very well, making it a very versatile, first-choice “go-to” all-purpose condenser mic. When recording a set of Gon Bops bongos, the Sony sounded warm and captured more of the overall drum tone.

Through the C-38B, both female and male vocals sounded full, and there was no folding up with loud singing right on the diaphragm. You'll need a pop filter, but the slight high-frequency lift on this mic more than makes up for any loss. The great proximity effect in unidirectional mode was useful to my thin-sounding singer. I had no sibilance problems with close singing and I didn't have to use the -8dB pad.

On acoustic guitars, once again the C-38B's full, fat sound worked great, although I had to move it back from the guitar and crank more mic preamp gain. I tried the M1 roll-off position when I got close to the guitar's sound hole, and it did the trick. Position V1 is fairly drastic but usable if you're close-miking and trying to slim down a large-bodied acoustic, such as a Gibson J-200, to sound more like a bluegrass guitar, such as a Collings 0M-2H. The V2 position is very telephonic-sounding and works for special effects. Switching to omnidirectional also sounded great on acoustic: I could move in closer without the bass build-up.

In general, either pattern is crisp and even — not overly bright or thick in the lower midrange. If you always carve acoustics to fit the part or track with an equalizer (like I do), this mic will start you out in a good place. Finally, for room miking, the C-38B in omni mode picked up everything in good balance. The smooth response de-emphasized the room's inherent boxy sound.


The C-38B is the perfect choice for an all-around utilitarian studio microphone that you can freely use with great results for any recording task. I'd recommend a stereo pair for room mics, string sections or drum overheads. The clear high-frequency response and solid low frequencies will present you with a true-to-life sonic picture. The C-38B sells for $2,200.

Sony Professional Audio, 800/686-7669,

Barry Rudolph is an L.A.-based recording engineer. Visit his Website at

Click here for C38B specs!

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