AKG C 391B Modo De Empleo página 17

2. Circuitry incorporating an input transformer without centre tap
(ungrounded)
3. In case where single ended (grounded) amplifier inputs, or where no
input transformers are available, either capacitors or optional trans-
formers have to be wired into the audio lines to prevent any current
leakage into the input circuitry.
The components in the last figure may be easily and economically
added to most existing input circuitries and would save the opera-
tion of external powering elements.
The following values for Rv (or 2 x Rv) are standardized:
+ UB
12 V ± 2 V
24 V ± 4 V
48 V ± 4 V
Please note:
The resistors 2 x Rv have to be at least of the 0.5 % tolerance type to
satisfy the symmetry requirements.
Cleaning Hints:
All surfaces may be safely cleaned from time to time with methylated
spirit or alcohol. The foam windscreen should be occasionally soaked in
a non-aggressive detergent/water solution and will be ready for use
after drying.
Rv
330 ohms
680 ohms
3300 ohms
2 x Rv
680 ohms
1200 ohms
6800 ohms
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