Rane BB22 Data Sheet

DATA S HE E T / MANUAL

General Description

The Rane BB 22 Balance Buddy is a handy professional­grade tool used to provide isolation for and convert unbal­anced -10 dBV consumer level RCA outputs up to balanced
+4 dBu professional XLR inputs. The BB 22 converts one
pair from -10 dBV to +4 dBu. There are two male XLR
connectors and two RCA jacks.

Unbalanced lines should always be kept to 10 feet or less
to prevent undesireable effects such as hum and noise. The
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 amplifier 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 distortion, wide bandwidth and high signal
level handling capability.

The BB 22’s isolation transformers provide a quick and
affordable answer to most jobs requiring signal level conver­sion and output balancing.

BB 22

BALANCE BUDDY

Features

• 2 Channels of -10 dBV to +4 dBu Conversion

• Nickel Core “80” Ni Transformers

• Wide Bandwidth

Parameter Specification Limit Units Conditions/Comments

Transformer Cons tructi on Nickel Core Bo bbin Wound Grade “80” N i
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 % ohms Load impedance 15k ohms

Insertion Loss 0.5 0.1 dB With recommended load impedance
DC Resistance 47.5/200 10% ohms -10 dBV/+4 dBu
Frequency Response 20-20 kHz ±2 dB +4 dBu out; recom. load impedance
THD + Noise less tha n .05 (40 H z-20 kH z) max % +4 dBu out
Unit: Agency Listing UL/CSA Exempt Class 2 equipment

CE-EMC Exempt pas sive 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 specifications apply both directions, unless noted. 0 dBu=0.775 volts; 0 dBV=1.0 volts

WEAR PARTS: This product contains no wear parts.

• Low Distortion

• +24 dBu Maximum Levels

• RCA & XLR Connectors

Data Sheet-1

BB 22

BALANCE BUDDY

Application Information

Conversion Ratio

The casual observer would think to convert -10 dBV to
+4 dBu, you would need 14 dB of gain. The casual observer
would be wrong. You only need 12 dB of gain. The reason is
not only do you change levels, you also change reference
levels—from dBV to dBu. The first (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 ohms, which equaled
.775 volts).

Driving Impedances

Some people wrongly feel you cannot use a transformer to
convert between -10 dBV and +4 dBu because of low
impedances. This is not a problem as long as you use them to
interconnect equipment with at least 15k ohms input imped-
ance. Since most professional products have input imped­ances of 20k ohms or greater (50k and 100k ohms are not
uncommon), this should never be difficult. A 15k ohm load
winds up looking like 1k ohm to the equipment with the

-10 dBV output (due to transformer action). This may seem
excessively low, but is not in practice. The 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
1k ohms only requires 3.16 milliamps, which is a very modest
requirement for any -10 dBV equipment to deliver.

Block Diagram

Wiring

The 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. This 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. The only problem arises in the gender of the XLR
connector. The solution requires same-sex XLR adaptors or
special cables.

©Rane Corporation 10802 47th Ave. W., Mukilteo WA 98275-5098 USA TEL [phone] FAX [phone] WEB http://www.rane.com

Data Sheet-2

All features & specifications subject to change without notice DOC 102929 PN 10585