Index
Lyra Maintenance Manual. D&R Electronica Weesp B.V. tel. +31 294 418041.
5. Identifying the PCB’s in a Lyra
1. The Core PCB (1)
This PCB is the Core of the Lyra. On this PCB there is a Texas Instruments DSP
processor which processes the digitized audio signals (i.e. Leveling, EQ, Dynamics etc…).
Also on this PCB is the digital routing matrix which is located inside the Altera Cyclone
FPGA. This IC also contains the Processor (called NIOS) which controls the complete
Lyra including the Web server and FTP server.
All the necessary specific voltages (+1V2, +1V5 and the +3V3) are generated locally. How
and where they can be measured is explained elsewhere in this manual.
2. The Digital in/output PCB (2)
This PCB receives and sends all digital audio data. All inputs have individual Crystal
CS8420 sample rate converters and have transformers on the in and outputs.
This PCB also serves as distribution board for all the clock signals as well as distributing
the power. All GPIO´s are located on this board and the CobraNet interface will be
installed on this PCB (when ordered).
The board creates its own +3V3 for the Clock Buffer IC´s, and a se3V3 for the
CobraNet interface card. How and where to measure these voltages is explained elsewhere
in this manual.
3. The Analogue in/output PCB (3)
This board has the Burr Brown PCM1804 AD converters on board for all your analogue
inputs including the Microphone inputs. Also it contains the Burr Brown PCM1793 DA
converters for all main (Prog, SUB, CRM etc…) outputs. The Microphone input insert
jacks are also located on this board.
This board creates its own +3V3 for the AD and DA converters. How and where to
measure these voltages is explained elsewhere in this manual.
