FOURAUDIO PPA Series, Datasheet And Manual, Page: 8 / 37

Date: 2017-06-28
PPA DSP amplifier user manual
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3. Introduction
The PPA Series provides a high-quality DSP-powered class-D amplifier solution for active loudspeakers. It
features amplifier modules from Pascal ®, analogue and digital AES and optional Dante® inputs.
The PPA range covers modules with one to four output channels and either active (low-noise fan) or passive
cooling.
4. Product Specifications
Analog signals are converted to digital by a dual range ADC for high dynamic input range. Signal processing is
done in 32-bit floating point on an Analog Devices SHARC® DSP.
In general, FIR filters are available for linear phase system response. Usual IIR X-Overs and EQs can be used
instead or additionally. An advanced limiter concept protects speakers and prevents amp and PSU overheating.
The PPA is programmed via USB. The operational status of the PPA is shown on the touch display which can also
be used to e.g. change presets.
Main features:

Up to 2500 + 2x800 W Output power (PPA2200-3)

1..4 Channel versions available to cover a wide variety of speaker configurations

Dante digital audio network optionally available

32-bit floating-point SHARC DSP

Analog, digital AES and optional Dante® signal input

Output channels are bridgeable to double single-channel power

PFC (power factor correction)

Low-noise fan or passive cooling option

USB and touch screen
4.1. Cooling Concept
The PPA models with active cooling use low-speed spinning fans. In some cases (Hi-Fi applications), these fans
could produce an audible noise. For these applications, PPA models with passive cooling can be used. They are
fanless and provide a milled aluminum backplate. The passive cooling option is available for PPA modes up to the
PPA 1000-4.
4.2. DRC or 2CH?
To achieve a higher signal-to-noise ratio all single input channel models use a dual-range analog-to-digital
converter. It is also possible to split the dual-range converter and have two analog inputs. Please also see 6.
You can tell 2Ch from DRC models from the nr of XLR jacks. In addition to one analog input and one AES input,
the 2Ch model has a third XLR jack for the second analog input.
PPA – 1000 – 4 – AC - DRC
Total output power
Number of amp outputs
[1..4 channels]
AC: active cooling (fan)
PC: passive cooling
DRC: dual range converter)
2CH: 2 analog inputs
Figure 1 PPA product naming scheme