Unbalanced to Balanced
ANYWHERE YOU NEED...
You Need The ST-UBA2!
The ST-UBA2 is part of the group of versatile STICK-ON products from Radio Design Labs. STICK-ONs
feature the advanced circuitry for which RDL products are known, combined with unequalled versatility in
mounting possibilities. The durable adhesives provided with the ST-UBA2 permit permanent or removable
mounting. Numerous available mounting accessories, brackets and rack-mount chassis are optionally available
to facilitate any system design.
FUNCTIONAL DESCRIPTION: The ST-UBA2 is a dual channel line-level device with separate left (L) and
right (R) inputs. Each input is unbalanced and is designed to accept input signals from -20 dBV to -10 dBV.
A-multi-turn gain potentiometer is provided for setting the level independently for each input. The unbalanced
signals are converted to balanced signals in the module. The balanced line amplifiers provide low impedance,
balanced +4 dBu outputs. In addition to the LEFT and RIGHT outputs, a third MONO output is provided. This
balanced output is the sum of the left (L OUT) and right (R OUT) balanced outputs. The mono output is 6 dB
below each of the individual channel outputs thereby producing identical levels at all three outputs when the
inputs are fed with in-phase signals.
Separate LED level metering is provided for the left and right outputs. Each channel is equipped with two
LEDs. A green LED illuminates at 15 dB below +4 dBu. The intensity of the green LED progresses from
minimum at -11 dBu to full intensity at +4 dBu. The adjacent red LED illuminates at +4 dBu. This two-LED
meter provides a compact, accurate indication of dynamic audio. The ballistics of the metering circuit follows
the same rise and fall times of a standard VU meter. Therefore, the audio may be adjusted for maximum
intensity of the green LED. Flashing of the red LED is equivalent to a VU meter needle swinging above the “0”
level. The meter is calibrated to the standard operating level of +4 dBu.
Module operation is from a 24 Vdc ground-referenced power supply.
TYPICAL APPLICATION: The ST-UBA2 is used in any application requiring conversion from unbalanced
consumer format signals to professional +4 dBu. It may be used to balance audio from CD players, cassette
decks, computer sound cards, televisions, and a wide variety of other unbalanced sources. The mono sum
output may be used to drive patch-bay jacks, monitors or subwoofer amplifiers.
The audio clarity, low noise, low distortion and excellent crosstalk performance makes this module ideally
suited to a wide variety of demanding audio applications. Use this module in conjunction with other RDL
modules as part of a high quality, flexible audio/video system.
To Convert Stereo IHF Levels to Stereo
Additional MONO Sum Output
Independently Adjustable Gain
Ground-referenced Conversion Module
LED VU Metering for Each Channel
Unparalleled Audio Performance
659 N. 6
Prescott, AZ., USA 86301
FAX (928) 443-9392