CharterOak Acoustic Devices SA538B
Multi-Pattern Tube Condenser Microphone
The SA538B is a large-diaphragm, multipattern tube condenser microphone, designed to provide a tonal contrast to the company’s flagship model, the SA538.
Both mics use a 12AX7/ECC83-based tube amplifier circuit, with an external power supply providing pattern control from omni to figure-8 with 7 intermediate steps. Neither mic provides a pad or high-pass filter. Both use dual-diaphragm capsules (presumably 34mm) with 27mm diaphragms.
Both mics follow CharterOak’s rigorous multi-step quality control and burn-in procedure, culminating in a half-hour of studio time with an experienced engineer to do a final usage inspection on each individual microphone.
The SA538B uses an edge-terminated capsule design. Charter Oak imports capsule metalwork from a Chinese supplier, remachines the parts to ensure consistency, and then ships the parts back to China for diaphragm fitting and capsule assembly.
Its noise rating is a bit better than the SA538, with an A-rated measure of 20dB. The average rating for this type of microphone (large-diaphragm tube condensers) is lower, around 16dBA for all the mics we’ve seen.
Like the SA538, the ‘B’ version ships with its tube power supply in a locking flight case with a shockmount and cables. The mic is covered by a lifetime warranty.
EQ Magazine
I had to record some piano for a very sparse, weird arrangement where the overall tone was really going to affect the presentation… with the CharterOak in figure 8, on a big upright piano, a Sage electronics class A mic pre [the SE-PRE1], and a Pultec EQP1 I got one of the most amazingly detailed, forward, lifelike piano sounds I have ever recorded with any single microphone… The bottom of the piano was resonant and solid, the mids were insanely detailed, and the hammer/highs were simply perfect.
The CharterOak Acoustic Devices SA538B is also known as: SA-538B.
The mic was released in 2005.
Specifications
Frequency Response - CardioidClick Graph to Compare! |
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Pickup Patterns | Pads & Filters |
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Omnidirectional
(12 mV/Pa; 25 - 20,000 Hz) Cardioid (12 mV/Pa; 25 - 20,000 Hz) |
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Capsule Dimensions | Impedance | SPL/Noise |
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Diaphragm diameter: 27mm Diaphragm gauge: 6 microns |
200 Ohms (Low) | Max SPL: 125 dB Self-noise: 20.0 dB(A) |
Weight | Length | Max Diameter | Interface(s) |
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n/a | n/a | n/a |
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Power Specifications |
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