Rane BB 22 User manual

Data Sheet-1
BB 22
BALANCE BUDDY
General Description
e Rane BB 22 Balance Buddy is a handy professional-grade
tool used to provide isolation for and convert unbalanced -10
dBV consumer level RCA outputs up to balanced +4 dBu profes-
sional XLR inputs. e BB 22 converts one pair from -10 dBV
to +4 dBu. ere are two male XLR connectors and two RCA
jacks.
Unbalanced lines should always be kept under 10 feet (3
meters) to prevent undesirable eects such as hum and noise. e
BB 22 allows conversion to balanced lines that can be run across
a studio or a house without loss of signal quality. For instance, a
BB 22 may be mounted to the back of a jukebox converting its
unbalanced outputs to balanced lines, feeding an amplier in
another room.
Signal-to-noise performance is perfectly preserved using the
BB 22, since it uses only passive transformers to convert signal
levels. It adds no additional noise whatsoever. Use of professional
quality nickel core (“80” Ni) transformers guarantee low distor-
tion, wide bandwidth and high signal level handling capability.
e BB 22’s isolation transformers provide a quick and af-
fordable answer to most jobs requiring signal level conversion
and output balancing.
Features
• 2 Channels of -10 dBV (RCA) to +4 dBu (XLR) Conversion
• Nickel Core “80” Ni Transformers
DATA SHEET / MANUAL
WEAR PARTS: is product contains no wear parts.
• Wide Bandwidth - Low Distortion
• +24 dBu Maximum Levels
Parameter Specication Limit Units Conditions/Comments
Transformer Construction Nickel Core Bobbin Wound Grade “80” Ni
Turns Ratio 1:3.89 -10 dBV (316 mV): +4 dBu (1.23 V)
Maximum Levels
..........-10 dBV In +10 (40 Hz-20 kHz); +4.5 (20 Hz) 0.5dB dBV 1% THD point
..........+4 dBu Out +24 (40 Hz-20 kHz); +18.5 (20 Hz) 0.5dB dBu 1% THD point
Input Impedance (Load Impedances as Shown)
..........-10 dBV 1k 5 % Ω Load impedance 15k Ω
Insertion Loss 0.5 0.1 dB With recommended load impedance
DC Resistance 47.5 / 200 10% Ω -10 dBV / +4 dBu
Frequency Response 20-20 kHz ±2 dB +4 dBu out; recom. load impedance
THD + Noise less than .05 (40 Hz-20 kHz) max % +4 dBu out
Unit: Agency Listing UL/CSA Exempt Class 2 equipment
CE-EMC Exempt passive device
CE-Safety Exempt extra low voltage device
Unit: Construction All Steel
..........Size 1.65"H x 5.1"W x 4.25"D (4.2 cm x 13 cm x 10.8 cm)
..........Weight 1 lb (.45 kg)
Shipping: Size 3.6" x 11.75" x 7.2" (9.5 cm x 30 cm x 18 cm)
..........Weight 2 lb (.9 kg)
All specications apply both directions, unless noted.

Data Sheet-2
BB 22
BALANCE BUDDY
All features & specications subject to change without notice DOC 102929
©Rane Corporation 10802 47th Ave. W., Mukilteo WA 98275-5098 USA TEL [phone] FAX [phone] WEB www.rane.com
Block Diagram
Dimensions
Application Information
Conversion Ratio
e casual observer would think to convert -10 dBV to +4 dBu,
you would need 14 dB of gain. e casual observer would be
wrong. You only need 12 dB of gain. e reason is not only do
you change levels, you also change reference levels—from dBV
to dBu. e rst (dBV) references everything to 1.0 volt, while
the second (dBu) references everything to 0.775 volts (this comes
from the old power reference of 0 dBm, which equaled 1mW into
600 Ω, which equaled .775 volts).
Driving Impedances
Some people wrongly feel you cannot use a transformer to con-
vert between -10 dBV and +4 dBu because of low impedances.
is is not a problem as long as you use them to interconnect
equipment with at least 15k ohms input impedance. Since most
professional products have input impedances of 20 kΩ or greater
(50k and 100 kΩ are not uncommon), this should never be dif-
cult. A 15 kΩ load winds up looking like 1 kΩ to the equip-
ment with the -10 dBV output (due to transformer action). is
may seem excessively low, but is not in practice. e maximum
transformer output level of +24 dBu occurs with an input level
of +10 dBV, which equals 3.16 volts. And 3.16 volts driving 1 kΩ
only requires 3.16 milliamps, which is a very modest requirement
for any -10 dBV equipment to deliver.
Wiring
e BB 22 follows AES/ANSI/IEC standards of pin 2 positive
and pin 3 negative. Note the shields (commons) of the RCA
jacks are not tied together. is provides better ground isolation
of the unbalanced units. A positive signal applied to the tip of
the RCA jack causes a positive signal to appear on pin 2 of the
XLR, and vice-versa if signal direction is reversed.
Signal Direction
Signal can be converted through the channels either direction.
e only problem arises in the gender of the XLR connector. e
solution requires same-sex XLR adaptors or special cables.
INPUT 1
-10 dBV +4 dBu
-10 dBV +4 dBu
INPUT 2
OUTPUT 1
OUTPUT 2
4.225"
0.15"
2.5"
5.1"
0.775"
0.35"
1.636"
OUTPUT 1 OUTPUT 2
+4dBu +4dBu
-10dBV -10dBV
INPUT 2
INPUT 1
BALANCE
BUDDY
RANE CORP.
MADE IN U.S.A.
ACN 001 345 482
1 2
BB 22