User manual RANE BB 44X

[. . . ] DATA SHEET / MANUAL BB 44X BALANCE BUDDY BB 44X BALANCE BUDDY General Description The 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). The BB 44X converts one pair from -10 dBV to +4 dBu and another pair from +4 dBu to -10 dBV simultaneously. [. . . ] RANE CORP. BB 44X 56 +4 dBu INPUTS 5 -10 dBV OUT 7 -10 dBV IN 78 +4 dBu OUTPUTS BALANCED 2 UNBALANCED 4 BALANCED ACN 001 345 482 BALANCED 6 UNBALANCED 8 BALANCED Application Information Conversion Ratio The casual observer would think to convert -10 dBV to +4 dBu, you would need 14 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 , 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 15 k input impedance. Since most professional products have input impedances of 20 k or greater (50k and 100 k are not uncommon), this should never be difficult. A 15 k load winds up looking like 1 k 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 1 k only requires 3. 16 milliamps, which is a very modest requirement for any -10 dBV equipment to deliver. Wiring The BB 44X follows AES/ANSI/IEC standards of pin 2 positive and pin 3 negative. Note the shields (commons) of the RCA jacks are tied for the Inputs and the Outputs but not to each other. This 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. That means there is the possibility of having four channels -10 dBV unbalanced to +4 dBu balanced, or vice versa (in the standard unit). [. . . ] 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. ©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 All features & specifications subject to change without notice DOC 102926 [. . . ]