Owner’s Manual
HPA-DAC4
Dante
®
Accessory Card
AtlasIED.com
– 3 –
Specifications are subject to change without notice.
1601 Jack McKay Blvd. • Ennis, Texas 75119 U.S.A.
Telephone: 800.876.3333 • Fax: 800.765.3435
Audio Applications
When installed, the HPA-DAC4 converts the HPA Series amplifier into a digital audio network
amplifier and makes the HPA Series amplifier the “go to” solution for a variety of applications
including:
• Restaurants
• Government facilities
• Schools
• Industrial facilities
• House of worship
Selecting the dBFS Reference on the HPA-DAC4
The HPA-DAC4 comes with a choice of dBFS (Decibels Full Scale) gain selections of 0dBFS = 10dBu
and 0dBFS = 20dBu. Factory default for the card is 0dBFS = 20dBu. There is a 2-pin header on the
card that is the OdBFS gain selection. When a shunt is applied to the header, the 0dBFS = 20dBu
setting is engaged. When the shunt is removed the setting is 0dBFS = 10dBu. Most pro audio
equipment gains are in the range of 20dBu – 24dBu. Read the entire manual to understand these
settings.
Matching Gain from a Source to the HPA Series Amplifier In a Dante
®
Network
Understanding the gain structure is very important to avoid clipping the audio signal or amplifier
output. There are three potential ways to clip the signal chain.
1.
Amplifier Input Clipping
- This occurs when the applied input signal exceeds the maximum input
level of the amplifier input stage.
2.
Amplifier Output Clipping
- Driving the amplifier to maximum output level using the factory default
requires 0dBu or .775V of signal when the channel level control is set to maximum or the all up fully
clockwise.
Note:
AtlasIED recommends the level to be set with the level being controlled from
the source. Exceeding .775V or 0dBu level will cause the amplifier output stage to clip.
3.
Digital Clipping
- This occurs when the 0dBFS levels are exceeded. This is very important to
understand. Several examples are provided to help understand digital to analog gain structure.
Note:
AtlasIED recommends to always place a limiter set for 0dB in the signal path prior to the
Network Output of the transmitting device. This is the best way to prevent clipping the HPA-DAC4.
Shunt on 0dBFS = 20dBu, factory default
Shunt off 0dBFS = 10dBu
