www.bockaudio.com
Power Supply and Cable
The Bock Audio P-251 full linear power supply features simple shunt B+ regulation and
active current source for the heater. The outputs and cable pinouts are shown in the
table at right.
Specifications
Patterns:
Remote continuously variable omni
through cardioid and figure 8
Frequency Range:
10 Hz to 18 kHz, ±2 dB
Sensitivity:
33
mv/Pa
Equivalent Noise:
19 dB (“A” weighted), 29 dB (unweighted)
Distortion vs. SPL @ 1 kHz:
(increasing distortion is non-exponential, nearly linear, and primarily 2nd harmonic)
112 dB = 0.5% THD
118 dB = 1% THD
129 dB = 2% THD
Impedance:
200 Ohms true transformer balanced
Recommended load:
2K Ohms
Dynamic range:
99 dB (max SPL-”A”noise)
S/N (94 dB-noise):
75 dB (“A” weighted), 65 dB (unweighted)
Capsule size:
1” diameter, dual symmetrical backplate K67 type
Tube type:
New Old Stock EF732
Dimensions:
2” dia x 9” oal (50 x 228 mm)
Weight:
1 lb 9.3 oz (1.58 lbs) = 716 g
Shipping weight:
12 lbs
Power Supply:
P251 true linear, factory wired 115v or 230v operation
Safety
Pin #
Output
1
audio (-)
2
audio (+)
3
pattern (if applicable)
4
heater (5.1v typical)
5
B+ (120v typical)
6
ground
case
shield
• CAUTION: Shock Hazard: Do not open microphone when connected to
power source. No user serviceable parts inside. Refer failed units to
qualified service personnel.
• VORTICHT: Shock gefar: Bitte nicht daf mikrofon offen wenn es
eingeschaltet ist einen stoppkontakt.
• Keine zu wartenden Teile im Inneren. Beziehen gescheitert Einheiten
qualifiziertem Service-Personal.
• ATTENCIONE: Choc hazard: N’ouvrez pas le microphone quand il y a
un connectionne avec un source d’electricity. Aucune pièce réparable
par l’utilisateur. Référer unités échoué à un personnel qualifié.
• ATTEZIONE: Riscchio di scossa: Non aprire il microfono quando e
attacato al’eletricita. Non contiene parti riparabili. Riferimento unità
riusciti a personale qualificato.
• Read the instructions.
• Keep these instructions.
• Heed all warnings.
• Follow all instructions
• Do not use this apparatus near water.
• Clean only with dry cloth.
• Do not block any ventilation openings. Install in accordance with the
manufacturer’s instructions.
• Do not install near any heat source such as radiators, heat registers,
stoves, or other apparatus (including amplifiers) that produce heat.
• Do not defeat the safety purpose of the polarized or grounding-type
plug. A polarized plug has two blades with one wider than the other.
• Protect the power cord from being walked on or pinched particularly
at plugs, convenience receptacles, and the point where they exit
from the apparatus.
• Only use with attachments/accessories specified by the
manufacturer.
• Refer all servicing to qualified service personnel. Servicing is
required when the apparatus has been damaged in any way, such
as power-supply cord or plug is damaged, liquid has been spilled
or objects have fallen into the apparatus, the apparatus has been
exposed to rain or moisture, does not operate normally, or has been
dropped.
• Soundelux USA U99
• UL 62368-2
• EN 62368-1
• Part 10004702 v201210