Technical data

ASTi DACS: Operation & Maintenance Manual (Version 4, Rev. B.1) www.asti-usa.com

Waveform Synthesizers

Waveform Synthesizers perform sound model digital signal processing and provide analog input

and output interface for external equipment such as speakers, headsets, and microphones.

Each individual Waveform Synthesizer contains a single DSP and performs all the signal process-

ing associated with a speciﬁc, user developed, sound model. The Waveform Synthesizer provides

up to eight channels of analog inputs and outputs (eight inputs and eight outputs) for interfacing to

external audio equipment. Converters are 16 bit delta sigma with sample rate tracking anti alias

ﬁlters which provide excellent sound quality.

Interface to external audio equipment such as headsets, mics, ampliﬁers, etc. is via a 37 pin,

female “D” connector located in the rear of the chassis. Connector pin-out is shown in Appendix

A and on the Waveform Synthesizer Engineering Drawing supplied with your DACS.

Analog inputs are full differential (balanced) and accept signal levels up to a maximum of 3Vp-p.

A preamp stage with gain adjustment from 0 - 60dB is included on each input. Gain values are set

using command lines in the Model Builder start-up conﬁguration ﬁle and can also be set through

the Model Builder software runtime environment directly. Maximum analog output levels are

approximately 5Vp-p into 600 Ohm or larger loads.

External audio equipment such as microphones, headphones, and speakers are connected to the

Waveform Synthesizer inputs and outputs either directly or through appropriate ampliﬁers and

preampliﬁers as required.

Sample Rate:

DSP sample rates on the Waveform Synthesizer are set by the user through the

Model Builder software environment. Sample rates range from 8kHz to 48kHz. Since the anti-

aliasing ﬁlters are sample rate tracking, no hardware reconﬁguration is required when sample

rates are changed.

Interconnection:

A high speed communication port connection is provided on the Waveform

Synthesizer. This port provides the capability to link up to three cards together, enabling sounds

and communications generated on one processor to be accessed by or mixed with the sounds and

communications generated by another processor.

A typical conﬁguration is connection of two Waveform Synthesizers. Connection of the two cards

allows audio inputs and sounds generated on one card to be mixed into outputs on the other card.

This high speed communications link between Waveform Synthesizers is made through a 40 pin

header on the top of each card or module. For multiple card-to-card connection, one 40 conductor

ribbon cable is installed and connected to all cards that need to pass sound between them.

In addition to linking hardware, you will also need to properly conﬁgure sound models running on

the DACS. For information about linking your sound models see the Global Channels section in

the Model Builder Reference Manual.

TDM Controller

The TDM Controller along with its associated Remote Interface Unit (RIU) components provide

similar functionality to the Waveform Synthesizer but with greater expandability and ﬂexibility.

The TDM Controller itself, has the same DSP processing capabilities as the Waveform Synthe-

sizer and is also physically mounted in the main DACS chassis.