DATA SHEET / MANUAL
BB 44X
BUDDY
BALANCE
General Description
e Rane BB 44X Balance Buddy is a handy professional-grade
tool used to convert and provide isolation for unbalanced -10
dBV consumer level RCA outputs up to balanced +4 dBu professional XLR inputs—and vice-versa. Two channels each way, or a
stereo pair each way (however you prefer to think about it). e
BB 44X converts one pair from -10 dBV to +4 dBu and another
pair from +4 dBu to -10 dBV simultaneously. ere are two
female and two male XLR connectors, and four RCA jacks.
Unbalanced lines should always be kept to 10 feet (3 meters)
or less to prevent undesireable effects such as hum and noise. e
BB 44X allows conversion to balanced lines that can be run across
a studio or a house without loss of signal quality. For instance, a
BB 44X
BALANCE BUDDY
stereo tape recorder with RCA connectors attaches easily—inputs
and outputs—to one BB 44X, allowing record source and playback amplifiers to be in another room.
Signal-to-noise performance is perfectly preserved using the
BB 44X, 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.
e BB 44X’s isolation transformers provide a quick and affordable answer to most jobs requiring signal level conversion and
output balancing.
Features
• 2 channels of -10 dBV to +4 dBu conversion
• 2 channels of +4 dBu to -10 dBV conversion
• Nickel core “80” Ni transformers
• Wide bandwidth
Parameter Specication 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 (In or Out )
..........-10 dBV +10 (40 Hz-20 kHz); +4.5 (20 Hz) 0.5dB dBV 1% THD point
..........+4 dBu +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 15 kΩ
..........+4 dBu 15k 5 % Ω Load impedance 1 kΩ
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 Hz -20 kHz ±2 dB +4 dBu In or Out; rec. load impedance
THD + Noise less than .05 (40 Hz-20 kHz) max % +4 dBu In or Out
Unit: Agency Listing UL, CSA, CE (EMC & Safety) Exempt
Unit: Construction All Steel
..........Size 1.75"H x 19"W x 5.3"D (1U) (4.4 cm x 48.3 cm x 13.3 cm)
..........Weight 4 lb (3 kg)
Shipping: Size 4.25" x 20.3" x 13.75" (11 cm x 52 cm x 35 cm)
..........Weight 8 lb (5 kg)
All specifications apply both directions, unless noted. 0 dBu = 0.775 volts; 0 dBV=1.0 volts
WEAR PARTS: is product contains no wear parts.
• Low distortion
• +24 dBu maximum levels
• RCA & XLR connectors
• Expandable to 8 channels with Option 88 accessory
Data Sheet-1
INPUT 1
T4
OUTPUT 1
9
11 4
2
3
2
1
+4 dBu -10 dBV
11 4
2
INPUT 2
+4 dBu
9 2
T3
-10 dBV
OUTPUT 2
3
11 4
2
1
OUTPUT 3
+4 dBu
9 2
T2
-10 dBV
INPUT 3
3
11 4
2
1
OUTPUT 4
+4 dBu
9 2
T1
-10 dBV
INPUT 4
3
1
MADE IN U.S.A.
RANE CORP.
+4 dBu
INPUTS
-10 dBV
IN
BALANCED WIRING:
PIN 2 = POSITIVE
PIN 3 = NEGATIVE
PIN 1 = CHASSIS GROUND
BB 44X
12
4
BALANCED
+4 dBu
INPUTS
56
BALANCED
+4 dBu
OUTPUTS
34
BALANCED
+4 dBu
OUTPUTS
78
BALANCEDUNBALANCED
3
-10 dBV
OUT
2
1
-10 dBV
IN
8
UNBALANCED
7
-10 dBV
OUT
6
5
ACN 001 345 482
OPTION 88
BB 44X
BALANCE BUDDY
Block Diagram
OPTION 88 Accessory
Rear Panel
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 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 Ω, 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. is is not a problem as long as you use them to interconnect equipment with at least 15 kΩ 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 difficult. A 15 kΩ load winds up looking like 1 kΩ to the equipment 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 44X follows AES/ANSI/IEC standards of pin 2 positive
and pin 3 negative. Note the shields (commons) of the RCA jacks
©Rane Corporation 10802 47th Ave. W., Mukilteo WA 98275-5098 TEL 425-355-6000 FAX 425-347-7757 WEB www.rane.com
Data Sheet-2
are tied for the Inputs and the Outputs but not to each other.
is allows ground isolation of stereo Input and Output pairs. A
positive signal applied to pin 2 of the XLR connectors causes a
positive signal to appear on the tip of the associated RCA jacks,
and vice-versa.
Signal Direction
Signal can be converted through the channels either direction. at means there is the possibility of having four channels
-10 dBV unbalanced to +4 dBu balanced, or vice versa (in the
standard unit). e only problem arises in the gender of the
XLR connector. e solution requires same-sex XLR adaptors or
special cables.
Chassis Grounding
A tapped hole and a #6-32 screw is provided for chassis grounding purposes. Good practice dictates earth-grounding the
BB 44X. If the grounding integrity of the rack screws is in doubt,
run a wire from this screw to a known earth ground.
OPTION 88
e OPT 88 (Option-88) expands the BB 44X into an eight
channel model. e OPT 88 consists of a printed circuit board
with four additional transformers and jacks soldered in place. e
OPT 88 installs easily in the blank side of the BB 44X. Assembly
is simple: remove the cover, install the board in place, and secure
with the supplied mounting screws. No soldering required; all
you need are #1 and #2 Phillips screwdrivers.
All features & specifications subject to change without notice DOC 102926
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