Mic Archive
Blue Cactus
Photo: Blue Microphones, from its manual, p. 1.

Blue Microphones

Blue Cactus

Large-diaphragm tube condenser (ECC 88), multi-pattern: nine patterns from omni to figure-8 set on the power supply; B7 capsule, transformer output

Approximate Some readings for this mic are uncertain; see the graphs.

Type
Condenser
Pattern
Omni / subcardioid / cardioid / supercardioid / figure-8
Sensitivity
−34.9 dBV/Pa computed
Self-noise
10 dB(A)
Max SPL
134 dB SPL
Impedance
50 Ω
Rated range
20 – 20k Hz

Frequency response

Angle
Distance

Frequency response: from the manual, p. 4. "Cactus | Omni" graph; dB scale +20 to -20, relative. Irregular (not logarithmic) frequency axis. Distance, room and smoothing not stated.

Dashed: outside the rated range, or simulated (other angles and distances). Hover or tap the graphs for values.

Polar pattern

Polar pattern: from the manual, p. 4. Polar plot in the omni panel; "Each Concentric Circle = +5 dB"; rings not labelled. Measuring conditions not stated. Approximate the graph's dB scale is not labelled and was assumed.

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All specs

From the manual
CapsuleB7: large diaphragm, single backplate, multi-pattern version of the B7 Bottle capsule. "a multi-pattern variation of the B7 Bottle microphone capsule. This large diaphragm, single back-plate capsule".p. 4
Sensitivity−34.9 dBV/Pa (18 mV/Pa). Not stated by the manufacturer: Converted from "18.0mV/Pa at 1kHz" (20 log10 0.018 = -34.9). Pattern not stated.p. 8
Self-noise10 dB(A), IEC 651. "Noise Level • 10 dB–A (IEC651)".
Max SPL134 dB SPL, 2.5 kohm load, 0.5% THD. "134 dB SPL (2.5kΩ, 0.5% THD)".
Signal-to-noise ratio84 dB, A-weighted, IEC 651. "S/N Ratio • 84 dB–A (IEC 651)".
Dynamic range124 dB, 2.5 kohm. "124 dB (@ 2.5kΩ)".
Output impedance50 ohm. "Output Impedance • 50Ω". The technical page (p. 7) says the 10:1 transformer gives "a low output impedance, typically 150 ohms".
Rated load impedance1000 ohm, not less than. "Rated Load Impedance • Not less than 1 kΩ".
Rated frequency range20 Hz to 20 kHz
PoweringPower Stream power supply (115/230 V AC, 50/60 Hz); no phantom power. "Power Requirement • Cactus Power Supply Unit 115/230 VAC, 50/60 Hz". Page 3: "It is not necessary or advisable to connect the Power Stream power supply to a 48V phantom power source."
Connectormulti-pin socket on the mic (Champagne tube cable to the power supply); XLR from the power supply. Page 3: "the multi-pin output jack"; the Quad cable runs from the Power Stream to the preamp. The pin count is not stated.p. 3
Weight800 g. "Weight • 800g".p. 8
Dimensions235 × 50 × 30 mm. "Dimensions • 235mm x 50mm x 30mm"; not said which is which.
Supplied accessoriesS2 Shock shock mount; flight case; IEC mains cable; Champagne tube mic cable; Power Stream power supply. "Included Accessories".
TubeECC 88, hand-selected after a week of burn-in; Class A, fully discrete, common-cathode circuitp. 7
Output transformerBlue's own, hand-built, balanced two-bobbin (humbucking) design, ratio 10:1
Pad and low cutNone: "there are no pad or low-cut filter switches in the microphone circuit"p. 3
Pattern switchNine positions on the Power Stream supply, omni (fully counter-clockwise) to figure-8 (fully clockwise)p. 8
Power supplyPower Stream with soft start: heater first, plate voltage ramped from 10 V to 120 V after about 80 s; output muted for about three minutes; 110/220 V AC switch (fuse 500 mA at 110 V, 250 mA at 220 V)
Transport screwsThree brass set screws lock the capsule for shipping; remove them before usep. 3
Recommended accessoriesThe Pop (universal windscreen); Quad Cable; S2 Shockp. 8
WarrantyThree years from purchase (to the original, registered owner)p. 9

Documents

Copies kept by Mic Archive, because manufacturers move and drop their documents. Each is © Blue Microphones, unchanged, with its original address.

Recording Hacks

Recommended for

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