Sonifex avn PC-AD2 User manual

Manufacturers of audio & video
products for radio & TV broadcasters
PC-AD2
2 Stereo Analogue I/O & 2 Stereo AES-3 I/O PCIe
Half Height Sound Card
HANDBOOK

PC-AD2 Handbook
This handbook is for use with the following product:
PC-AD2 2 Stereo Analogue I/O & 2 Stereo AES-3 I/O PCIe Half Height Sound Card
AW10789A Stock Code: 30-333
Revision 1.01, December 2016
©Sonifex Ltd, 2016
All Rights Reserved
Sonifex Ltd, 61, Station Road, Irthlingborough,
Northants, NN9 5QE, England.
Tel: [phone]
Fax: [phone]
Email: [email protected]o.uk
Website: http://www.sonifex.co.uk
Information in this document is subject to change without notice and does not represent a
commitment on the part of the vendor. Sonifex Ltd shall not be liable for any loss or damage
whatsoever arising from the use of information or any error contained in this manual.
No part of this manual may be reproduced or transmitted in any form or by any means, electronic
or mechanical, including photocopying, recording, information storage and retrieval systems, for any
purpose other than the purchaser’s personal use, without the express written permission of Sonifex
Ltd. Unless otherwise noted, all names of companies, products and persons contained herein are
part of a completely fictitious adaptation and are designed solely to document the use of Sonifex
product.
Made in the UK by

Contents & Figures
Contents
Product Warranty - 2 Year Extended i
Sonifex Warranty & Liability Terms & Conditions i
1. Definitions i
2. Warranty i
Unpacking Your Product ii
Repairs & Returns iii
Conformity iii
Safety & Installation of Mains Operated Equipment iii
Voltage Setting Checks iii
Fuse Rating iii
Power Cable & Connection iii
WEEE Directive iv
Atmosphere/Environment iv
1. PC-AD2 2 Stereo Analogue I/O & 2 Stereo AES-3 I/O
PCIe Half Height Sound Card 1
Introduction 1
2. Installation 4
Configuration 4
3. Windows Audio Operation 6
Audio Endpoints 6
Mixer API 6
Audio Engine 6
Windows Mono Recording Bug 7
Playback Endpoints 7
Recording Endpoints 8
Line Input 1 / Microphone Operation 9
4. GPIO 11
5. Technical Specification For PC-AD2 12
Figures
Fig 1-1: PC-AD2 With Small Bracket And Optional large Bracket 1
Fig 2-1: Device Manager Screen 4
Fig 2-2: PC-AD2 Properties/Configuration Screen 5
Fig 3-1: PC-AD2 Line Output 1 Properties/Advanced Screen 7
Fig 3-2: PC-AD2 Line Output 1 Properties/Levels Screen 8
Fig 3-3: PC-AD2 AES 3 Input 1 Properties/Levels Screen 8
Fig 3-4: PC-AD2 AES 3 Frequency Screen 9
Fig 3-5: PC-AD2 Recording Screen 9
Fig 3-6: PC-AD2 Microphone Properties/Custom Screen 10
Fig 4-1: PC-AD2 GPIO Demonstration Screen 11

Warranty Registration
Sonifex Limited y 61 Station Road y Irthlingborough y Northamptonshire y NN9 5QE y United Kingdom
Tel: [phone] y Fax: [phone] y Email: [e-mail] y Internet: www.sonifex.co.uk
As standard, Sonifex products are supplied with a
1 year back to base warranty.
If you register the product online, you can increase
your product warranty to 2 years and we can
also keep you informed of any product design
improvements or modifications.
To register your product, please go online to
www.sonifex.co.uk/register
Register Online for an
Extended 2 Year Warranty
Product:
Serial No:

i
Warranty
Product Warranty - 2 Year Extended
As standard, Sonifex products are supplied with a 1 year back to base
warranty. In order to register the date of purchase and so that we can keep
you informed of any product design improvements or modifications, it is
important to complete the warranty registration online. Additionally, if you
register the product on the Sonifex website, you can increase your product
warranty to 2 years. Go to the Sonifex website at: http://www.sonifex.
co.uk/technical/register/index.asp to apply for your 2 year warranty.
Note: For your own records the product serial number is recorded on the
CE certification page of this handbook.
Sonifex Warranty & Liability Terms & Conditions
1. Definitions
‘the Company’ means Sonifex Ltd and where relevant includes companies
within the same group of companies as Sonifex Limited.
‘the Goods’ means the goods or any part thereof supplied by the Company
and where relevant includes: work carried out by the Company on items
supplied by the Purchaser; services supplied by the Company; and software
supplied by the Company.
‘the Purchaser’ means the person or organisation who buys or has agreed
to buy the Goods.
‘the Price’ means the Price of the Goods and any other charges incurred by
the Company in the supply of the Goods.
‘the Warranty Term’ is the length of the product warranty which is usually
12 months from the date of despatch; except when the product has been
registered at the Sonifex website when the Warranty Term is 24 months
from the date of despatch.
‘the Contract’ means the quotation, these Conditions of Sale and any
other document incorporated in a contract between the Company and the
Purchaser.
This is the entire Contract between the parties relating to the subject
matter hereof and may not be changed or terminated except in writing in
accordance with the provisions of this Contract. A reference to the consent,
acknowledgement, authority or agreement of the Company means in
writing and only by a director of the Company.
2. Warranty
a. The Company agrees to repair or (at its discretion) replace Goods
which are found to be defective (fair wear and tear excepted) and
which are returned to the Company within the Warranty Term
provided that each of the following are satisfied:
i. notification of any defect is given to the Company immediately
upon its becoming apparent to the Purchaser;
ii. the Goods have only been operated under normal operating
conditions and have only been subject to normal use (and
in particular the Goods must have been correctly connected
and must not have been subject to high voltage or to ionising
radiation and must not have been used contrary to the
Company’s technical recommendations);
iii. the Goods are returned to the Company’s premises at the
Purchaser’s expense;
iv. any Goods or parts of Goods replaced shall become the
property of the Company;
v. no work whatsoever (other than normal and proper
maintenance) has been carried out to the Goods or any part of
the Goods without the Company’s prior written consent;

ii
Warranty
vi. the defect has not arisen from a design made, furnished or
specified by the Purchaser;
vii. the Goods have been assembled or incorporated into other
goods only in accordance with any instructions issued by the
Company;
viii. the defect has not arisen from a design modified by the
Purchaser;
ix. the defect has not arisen from an item manufactured by a person
other than the Company. In respect of any item manufactured
by a person other than the Company, the Purchaser shall only be
entitled to the benefit of any warranty or guarantee provided by
such manufacturer to the Company.
b. In respect of computer software supplied by the Company the
Company does not warrant that the use of the software will be
uninterrupted or error free.
c. The Company accepts liability:
(i) for death or personal injury to the extent that it results from the
negligence of the Company, its employees (whilst in the course
of their employment) or its agents (in the course of the agency);
(ii) for any breach by the Company of any statutory undertaking as
to title, quiet possession and freedom from encumbrance.
d. Subject to conditions (a) and (c) from the time of despatch of
the Goods from the Company’s premises the Purchaser shall be
responsible for any defect in the Goods or loss, damage, nuisance
or interference whatsoever consequential economic or otherwise or
wastage of material resulting from or caused by or to the Goods. In
particular the Company shall not be liable for any loss of profits or
other economic losses. The Company accordingly excludes all liability
for the same.
e. At the request and expense of the Purchaser the Company will test
the Goods to ascertain performance levels and provide a report of
the results of that test. The report will be accurate at the time of the
test, to the best of the belief and knowledge of the Company, and the
Company accepts no liability in respect of its accuracy beyond that
set out in Condition (a).
f. Subject to Condition (e) no representation, condition, warranty or
other term, express or implied (by statute or otherwise) is given by
the Company that the Goods are of any particular quality or standard
or will enable the Purchaser to attain any particular performance
or result, or will be suitable for any particular purpose or use
under specific conditions or will provide any particular capacity,
notwithstanding that the requirement for such performance, result or
capacity or that such particular purpose or conditions may have been
known (or ought to have been known) to the Company, its employees
or agents.
g. (i) To the extent that the Company is held legally liable to the
Purchaser for any single breach of contract, tort, representation
or other act or default, the Company’s liability for the same
shall not exceed the price of the Goods.
(ii) The restriction of liability in Condition (g)(i) shall not apply to
any liability accepted by the Seller in Condition (c).
h. Where the Goods are sold under a consumer transaction (as defined
by the Consumer Transactions (Restrictions on Statements) Order
1976) the statutory rights of the Purchaser are not affected by these
Conditions of Sale.
Unpacking Your Product
Each product is shipped in protective packaging and should be inspected
for damage before use. If there is any transit damage take pictures of the
product packaging and notify the carrier immediately with all the relevant

iii
CE Conformity
details of the shipment. Packing materials should be kept for inspection and
also for if the product needs to be returned.
The product is shipped with the following equipment so please check to
ensure that you have all of the items below. If anything is missing, please
contact the supplier of your equipment immediately.
Item Quantity
Product unit 1
IEC mains lead fitted with moulded mains plug 1
Handbook and warranty card 1
If you require a different power lead, please let us know when ordering the
product.
Repairs & Returns
Please contact Sonifex or your supplier if you have any problems with your
Sonifex product. Email [e-mail] for the repair/
upgrade/returns procedure, or for support & questions regarding the
product operation.
Conformity
The products in this manual comply with the essential requirements of the
relevant European health, safety and environmental protection legislation.
The technical justification file for this product is available at Sonifex Ltd.
The declaration of conformity can be found at:
http://www.sonifex.co.uk/declarations
Safety & Installation of Mains
Operated Equipment
There are no user serviceable parts inside the equipment. If you should
ever need to look inside the unit, always disconnect the mains supply
before removing the equipment covers. The cover is connected to earth
by means of the fixing screws. It is essential to maintain this earth/
ground connection to ensure a safe operating environment and provide
electromagnetic shielding.
Voltage Setting Checks
Ensure that the machine operating voltage is correct for your mains power
supply by checking the box in which your product was supplied. The voltage
is shown on the box label. The available voltage settings are 115V, or 230V.
Please note that all products are either switchable between 115V and 230V,
or have a universal power supply.
Fuse Rating
The product is supplied with a single fuse in the live conducting path of the
mains power input. For reasons of safety it is important that the correct
rating and type of fuse is used. Incorrectly rated fuses could present a
possible fire hazard, under equipment fault conditions. The active fuse is
fitted on the outside rear panel of the unit.
Power Cable & Connection
An IEC power connector is supplied with the product which has a moulded
plug attached.
The mains plug or IEC power connector is used as the disconnect device.
The mains plug and IEC power connector shall remain readily operable to
disconnect the apparatus in case of a fault or emergency.
The mains lead is automatically configured for the country that the product
is being sent to, from one of:

iv
Safety & Installation
Territory Voltage IEC Lead Type Image
UK & Middle East 230V UK 3 pin to IEC lead
Europe 230V European Schuko round 2 pin to
IEC lead
USA, Canada and
South America 115V 3 flat pin to IEC lead
Australia & New
Zealand 230V Australasian 3 flat pin to IEC lead
Connect the equipment in accordance with the connection details and
before applying power to the unit, check that the machine has the correct
operating voltage for your mains power supply.
This apparatus is of a class I construction. It must be connected to a mains
socket outlet with a protective earthing connection.
Important note: If there is an earth/ground terminal on the rear panel of
the product then it must be connected to Earth.
WEEE Directive
The Waste Electrical and Electronic Equipment (WEEE)
Directive was agreed on 13 February 2003, along with the
related Directive 2002/95/EC on Restrictions of the use of
certain Hazardous Substances in electrical and electronic
equipment (RoHS). The Waste Electrical and Electronic Equipment Directive
(WEEE) aims to minimise the impacts of electrical and electronic equipment
on the environment during their life times and when they become waste.
All products manufactured by Sonifex Ltd have the WEEE directive label
placed on the case. Sonifex Ltd will be happy to give you information about
local organisations that can reprocess the product when it reaches its “end
of use”, or alternatively all products that have reached “end of use” can be
returned to Sonifex and will be reprocessed correctly free of charge.
Atmosphere/Environment
This apparatus should be installed in an area that is not subject to excessive
temperature variation (<0°C, >50°C), moisture, dust or vibration.
This apparatus shall not be exposed to dripping or splashing, and no objects
filled with water, such as vases shall be placed on the apparatus.

1
PC-AD2 - Introduction 1
1. PC-AD2 2 Stereo Analogue I/O & 2 Stereo AES-3 I/O PCIe Half Height
Sound Card
Introduction
Fig 1-1: PC-AD2 With Small Bracket And Optional large Bracket

2
1 PC-AD2 - Introduction
The PC-AD2 is a dual stereo analogue input/output and dual stereo AES-3
digital input/output sound card in the PCIe half height format. One of the
analogue inputs can be used as a mic input, there is a dedicated AES-11
sync input and also 2 GPIOs. It is fully compatible with the Windows™
Wave, DirectSound, DirectShow, MCI and Core Audio APIs, supporting
audio up to 24 bit, 192kHz.
Category: Professional Sound Cards & Radio Capture Cards.
Product Function: Provides two AES-3 and two balanced analogue
audio inputs and outputs for use in a PC.
Typical Applications: Audio workstations, recording studios,
automation systems, audio logging, multi-channel playout.
Features:
ͻ 2 independent transformer-coupled AES-3 inputs and outputs.
ͻ 2 independent high level balanced stereo inputs and outputs.
ͻ Line input 1 can also act as a stereo mic, or dual mono mic input,
with +48V phantom power and limiter.
ͻ 1 AES-11 synchronisation input.
ͻ 2 opto isolated GPIOs.
ͻ 24-bit audio resolution.
ͻ Sampling rates up to 192kHz.
ͻ Asynchronous sampling rate converters on each input.
ͻ Card synchronisation to any input, AES-11 input or other PC-AD2
card.
ͻ 32 and 64 bit drivers for Windows7/8/10, Windows Server 2008/
R2, 2012/R2.
ͻ WDM-compliant supporting Wave, DirectSound, DirectShow and
Core Audio APIs.
ͻ Simultaneous record/play per channel.
The PC-AD2 is a professional-quality half-height PCIe audio input-output
card, offering both analogue and AES-3 stereo inputs and outputs. It
is supplied with a Windows WDM driver to provide full sound card
functionality on Windows 7, 8, 8.1, 10 and Windows Server 2008 R2, 2012
and 2012 R2. Many of the modern smaller PC systems only have space for
half height PCIe cards – the PC-AD2 card has been designed with this in
mind allowing a high channel count in a small format card.
The PC-AD2 has two stereo analogue inputs (the first of which can be used
as a stereo mic, or dual mono mic input) and two stereo analogue outputs,
two stereo AES-3 inputs and two stereo outputs, a dedicated AES-11 sync
input and two general purpose (GPIO) inputs and outputs.
When acting as a microphone input, phantom power can be applied at
+48V to the microphone input connection, but is removed if Line Input 1
becomes active. An audio limiter on the mic input automatically reduces
the microphone gain if the recording level approaches clipping.
The peak analogue level sets the clipping threshold for the analogue inputs
to one of +15, +18, +20, +22 or +24dBu. With the Windows endpoint faders
set to maximum, these levels correspond to full scale on the software audio
streams.
The card’s core sampling rate can be synchronised to an external source
chosen from either of the AES-3 inputs, the dedicated AES-11 sync input
or by using the inter-card cable (PC-AD2SY) for synchronising to another
PC-AD2.
Independent asynchronous sampling rate conversion on the inputs supports
rates from 32kHz to 192kHz, while the output rate can be configured as
192kHz, 96kHz, 88.2kHz, 48kHz, 44.1kHz or 32kHz, either free-running
or locked to an AES11 reference on any of the digital inputs. Software
sampling rate conversion is automatically inserted by Windows when the
application rate does not match the hardware rate, ensuring that files of

3
PC-AD2 - Introduction 1
any sample rate can be played and recorded. Extended software bit depths
of 32 and 24 bits are supported as well as 16 and 8 bits for playback and
recording. For each AES-3 input, the received sampling rate, frame lock and
sampling rate converter status is shown.
The playback and recording topology is virtualised because Windows
treats each input source as its own ‘endpoint’. Endpoints are the physical
audio sources and destinations, such as microphones, speakers and line
connectors. Each of the PC-AD2 card’s physical line inputs is represented
by an endpoint device, and as the hardware has separate A/D converters
or AES-3 receivers for each one, they can be used simultaneously. A
Microphone endpoint is also created which is shared with analogue Line
Input 1 endpoint. The Windows mixer API is virtualised for each application,
providing just a mute and volume control for each endpoint and affecting
only the audio going to and from that application.
The PC-AD2 has two optically-isolated general purpose inputs and outputs
which are accessed through a programming API supplied with the driver
package. A demo program is included with the driver package to illustrate
the operation of the GPIO API and to quickly test the GPIO functionality.
All the standard Windows audio APIs are available including the Core Audio
API, Wave, DirectSound, DirectShow, MCI and MIDI playback, as are a
variety of audio compression modes via the Windows Audio Compression
Manager or other software compression systems.
Multiple cards may be installed in a
single PC.
A 44-pin high-density D-type connector to XLRs & 9 pin D-type breakout
lead is offered as an option, the PC-AD2BC.

4
2 PC-AD2 - Installation
Fig 2-1: Device Manager Screen
2. Installation
The software package consists of the driver installation file (PCAD2x86.inf
or PCAD2x64.inf), the kernel-mode driver (PCAD2.sys), the configuration
DLL (PCAD2Coinstaller32.dll or PCAD2Coinstaller64.dll) and the catalogue
file (PCAD2x86.cat or PCAD2x64.cat).
Switch off the computer and carefully install the PC-AD2 card in any free
PCIe slot, observing the normal precautions against static electricity
discharge. Then switch the computer back on and boot Windows.
On Windows 7, right-click on the My Computer icon in the Start menu,
select Properties, then click on Device Manager. On Windows 8 and later,
open the Control Panel, go to System and Security and then System, and
open Device Manager from the link in the left hand pane. The PC-AD2 will
be listed under Other Devices as a Multimedia Audio Controller.
Right-click on it, select Update Driver Software, then click on Browse my
computer for driver software and click on the Browse button to navigate to
the driver’s location. Click on Next to install the driver.
At the completion of the installation process the loudspeaker symbol in the
toolbar at the bottom of the screen should be enabled. Your PC-AD2 is now
ready for use.
Configuration
To change the configuration, open Device Manager, expand Sound, video
and game controllers, then right-click on PC-AD2, select Properties and
click on the Configuration tab.
There are four configuration settings for the PC-AD2, these being Core
Sampling Rate, Analogue Maximum Level, Analogue Input 1 type, and Sync
Source.
The Core Sampling Rate sets the analogue converter rates, the AES-3
output rate and the internal rate of the Windows audio engine. Note that
the audio engine will automatically apply sampling rate conversion if an
application’s rate doesn’t match its internal rate.
The Analogue Maximum Level sets the clipping threshold for the analogue
inputs and outputs. With the Windows endpoint faders set to maximum,
these levels correspond to full scale on the software audio streams.
The Analogue Input 1 settings allow the first analogue input to be set as a
stereo line source, a stereo microphone or a pair of mono microphones.
The Sync Source setting allows the card’s core sampling rate to be
synchronised to an external source. Options include either of the AES-
3 inputs, the dedicated AES-11 sync input or the inter-card cable for
synchronising to another PC-AD2. Note that the card’s core sampling rate
must be the same as the external source for synchronisation to occur.

5
PC-AD2 - Installation 2
Fig 2-2: PC-AD2 Properties/Configuration Screen
For synchronising to another PC-AD2, connect a coaxial cable from SK1 on
the back of the master card to SK2 on the front of the slave card. Multiple
cards can be daisy-chained in this fashion, with each synchronised to the
preceding one.
At the bottom of the configuration page the PLL and AES input status is
shown. The PLL will indicate whether it is locked or unlocked and whether
its source is internal or external. When a sync source other than None is
selected, the source indicator will show external in green when it’s locked
to that source, or internal in orange if it’s unable to do so (typically because
the source sampling rate doesn’t match the card’s core sampling rate).
For each AES-3 input, the received sampling rate, frame lock and sampling
rate converter status is shown. If the displayed rate varies erratically or if
frame or converter lock can’t be achieved, check the cabling and make sure
the input isn’t doubly-terminated.

6
3 PC-AD2 - Windows Audio Operation
3. Windows Audio Operation
The audio subsystem of Windows 7, 8, 10 and corresponding server
versions changed substantially from earlier versions of Windows, although
most applications should continue to work without modification. The major
differences likely to affect users of the PC-AD2 are described below.
Audio Endpoints
Key to the new system is the concept of audio endpoints. These are the
physical audio sources and destinations, such as microphones, speakers and
line connectors.
Previously, an audio capture device would typically have multiple inputs
which were combined in a mixer or selector. Now, each input is represented
by its own device, and Windows itself operates the card’s selector to route
the chosen source to the A/D converter.
In the case of the PC-AD2, each of the physical line inputs is represented
by an endpoint device, and as the hardware has separate A/D converters
or AES-3 receivers for each one, they can be used simultaneously. A
Microphone endpoint is also created which is shared with analogue Line
Input 1, so only one of these can be active at any given time. When an
application opens a shared input endpoint, it is automatically activated and
the other shared endpoint is made unavailable.
Windows has a default playback endpoint and a default recording endpoint,
which are typically used by applications where the input or output device
cannot be explicitly chosen. To change the default endpoints, right-click on
the loudspeaker symbol, selecting Playback devices or Recording devices,
then right-click on the desired endpoint and select Set as Default Device.
The default device is remembered across reboots and should not need to
be set again. A default communications device can also be set for use by
telephony applications.
Mixer API
The legacy Windows mixer API is virtualised for each application, providing
just a mute and volume control for each endpoint and affecting only the
audio going to and from that application. The hardware controls on the card
itself are not accessible from the mixer API.
New applications can use the Core Audio APIs to directly access
the hardware mixer controls and peak meter nodes through the
DeviceTopology API and the EndpointVolume API (which includes the
IAudioEndpointVolume and IAudioMeterInformation interfaces). These are
documented in the Windows SDK available from Microsoft, however note
that these APIs don’t work with versions of Windows earlier than Vista.
Audio Engine
The Windows audio engine runs at a fixed sampling rate and bit depth.
The PC-AD2 driver sets the sampling rate to the card’s core rate and the
bit depth to 24-bit for all the inputs and outputs. The Windows sampling
rate converter is used whenever a different sampling rate or bit depth is
requested by applications. The engine bit depth for each endpoint can
be changed to 16-bit if required by selecting the endpoint, clicking on
Properties, and then clicking on the Advanced tab.
If your applications will be playing or recording at rates higher than 48kHz,
you will need to set the card’s core rate accordingly otherwise Windows will
down-sample to 48kHz.

7
PC-AD2 - GPIO 4
7
PC-AD2 - Windows Audio Operation 3
Fig 3-1: PC-AD2 Line Output 1 Properties/Advanced Screen
Windows Mono Recording Bug
Windows currently has a bug which causes mono recording streams to
capture only the left channel of the source, rather than mixing the left and
right as earlier versions did. As a workaround until this is fixed, the driver
provides a Mono Mix recording endpoint for each of the card’s inputs. By
default these are disabled, but can be individually enabled as follows.
Right-click on the loudspeaker symbol in the bottom right hand corner of
the screen and select Recording Devices. Right-click on any of the sources
and check Show Disabled Devices, which should then reveal two additional
sources called Input 1 Mono Mix and Input 2 Mono Mix. To enable these,
right-click on them and select Enable. Note that, after enabling, it will still
show as currently unavailable as these endpoints are multiplexed with the
normal stereo inputs and are only activated when opened by a recording
application. Also be aware that, for the same reason, the stereo and mono
mix endpoints for the same source can’t be used simultaneously.
The Mono Mix endpoints should be used for communications applications
such as Skype which open a mono capture stream.
Note that there are no Mono Mix endpoints associated with the mono
microphone inputs when that mode is selected as these are inherently
mono.
Playback Endpoints
Each of the analogue and AES-3 playback endpoints has a set of control
faders which are accessed by right-clicking on the endpoint, selecting
Properties and clicking on the Levels tab.
At the top is the master fader which sets the overall output level. Below this
are individual faders for each of the playback mixer sources.
The Wave source is the output from any playback software running on the
PC. By default it is set to 100%. If multiple applications are producing audio,
Windows automatically mixes their output, with sampling rate and bit
depth conversion applied when necessary, before applying the end result to
the card.
Below this are faders corresponding to the card’s inputs. Each input can be
passed directly to the output by opening the corresponding fader.

8
3 PC-AD2 - Windows Audio Operation
Fig 3-2: PC-AD2 Line Output 1 Properties/Levels Screen Fig 3-3: PC-AD2 AES 3 Input 1 Properties/Levels Screen
Recording Endpoints
Each of the analogue and AES-3 recording endpoints has a fader and mute
control which are accessed by right-clicking on the endpoint, selecting
Properties and clicking on the Levels tab.
The Listen option allows the input’s audio to be routed by Windows to any
audio output device on the PC. The listen settings are preserved across
reboots and take effect even if no user is logged in.
The AES-3 inputs have asynchronous sampling rate converters that convert
the received streams to the card’s core sampling rate and take care of any

9
PC-AD2 - GPIO 4
9
PC-AD2 - Windows Audio Operation 3
Fig 3-4: PC-AD2 AES 3 Frequency Screen
Fig 3-5: PC-AD2 Recording Screen
sample timing differences. All aliasing products are attenuated by more
than 120dB. The converter’s passband frequency response is shown below,
normalised to the lower of the input and core sampling rates. The vertical
scale is 10dB per division.
Line Input 1 / Microphone Operation
The first analogue input channel on the PC-AD2 can be used either as a line
level, stereo microphone or dual mono microphone input. The recording
endpoints will change according to the mode selected. (see the earlier
section for an explanation of audio endpoints).
A shared endpoint is automatically activated when an application starts
recording from it, with the other endpoint made unavailable. The PC-AD2
uses this mechanism to switch the microphone preamplifier and optional
+48V phantom power on and off.
If only one or the other is ever going to be used, it’s recommended that the
unused endpoint be disabled so that the required one is always available.
To disable an endpoint, open the Sound applet by right-clicking on the
loudspeaker symbol in the bottom right hand corner of the screen and
selecting Recording devices. Right-click on the endpoint in question and
select Disable.

10
3 PC-AD2 - Windows Audio Operation
Fig 3-6: PC-AD2 Microphone Properties/Custom Screen
To adjust the sensitivity of the microphone input, right-click on the
endpoint, select Properties and click on the Levels tab. The default setting
is -20dB but can be adjusted from 0dB to -60dB. Note that the setting
display can be switched between percentage and decibels by right-clicking
on it and selecting the desired option.
Each microphone endpoint has two additional settings for phantom power
and an audio limiter. To access these, right-click on the endpoint, select
Properties then click on the Custom tab.
Phantom power, when selected, applies +48V to the microphone input
connections. When the stereo microphone mode is selected, phantom
power is applied to both the left and right inputs, while in dual mono
microphone mode, the phantom power on each input is independently
settable.
The audio limiter automatically reduces the microphone gain if the
recording level approaches clipping. Because of the twelve sample delay
through the A/D converter, the limiter can’t entirely prevent clipping but
will minimise its effects. In stereo microphone mode, the limiter will jointly
act on both channels when either exceeds its threshold, while in mono
microphone mode, the limiters on each channel are fully independent.

11
PC-AD2 - GPIO 4
4. GPIO
The PC-AD2 has two optically-isolated general purpose inputs and outputs
which are accessed through a programming API supplied with the driver
package.
The API library itself is in the PCAD2.dll file. To access this from your
application software, insert the header file PCAD2.h into your source and
link to the library file PCAD2.lib. 32-bit and 64-bit versions of these files are
provided.
The API consists of four functions as follows.
HANDLE PCAD2Open (unsigned CardInstance);
This returns a handle to the card for use with the other API functions. When
no longer required, this handle must be closed by calling the Windows
function CloseHandle.
When multiple cards are in use, CardInstance selects the card. If only one
card is present, set this to zero.
unsigned PCAD2GetGPI (HANDLE CardHandle);
This returns the state of the two general purpose inputs in the least
significant bits. Set CardHandle to the handle returned from PCAD2Open.
void PCAD2SetGPO (HANDLE CardHandle, unsigned Outputs);
This sets the state of the two general purpose outputs from the least
significant bits of Outputs. Set CardHandle to the handle returned from
PCAD2Open.
__int64 PCAD2GetHardwareID (HANDLE CardHandle);
This returns the unique 64-bit hardware identifier for the card. It can be
used to disambiguate multiple cards. The same identifier is shown on the
card’s Configuration page in Device Manager.
A simple demonstration program is included with the driver package
to illustrate the operation of the GPIO API and to quickly test the GPIO
functionality.
Fig 4-1: PC-AD2 GPIO Demonstration Screen
The input indicators will glow yellow when the corresponding inputs are
active, while holding down the left mouse button on the output buttons will
activate the corresponding outputs.

12
5 PC-AD2 - Technical Specification
5. Technical Specification For PC-AD2
Operating Systems Supported
Platform: Windows 7, 8, 8.1 and 10 (32-bit and 64-
bit versions
Server 2008 R2, 2012 and 2012 R2.
PCIe Specification
Card Interface: Single lane PCIe 1.1
Audio Specification
Analogue Sampling Rate: 32kHz, 44.1kHz, 48kHz,
88.2kHz, 96kHz or 192kHz
Analogue Resolution: 24 bits
Dynamic Range: >100dB typical (unweighted)
Analogue THD+N: < 0.0015% (-96dB)
Analogue Input Interface: 2 x stereo balanced analogue line (1 can be
switched to microphone)
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Analogue Maximum Signal: +15dBu, +18dBu, +20dBu, +22dBu,
+24 dBu (software settable)
Microphone Sensitivity: -58dBu to +2dBu for full scale input
Microphone E.I.N.: -128dBu A weighted (Sample rate 48kHz,
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Microphone CMRR: 77dB @ 1kHz, 77dB @ 10kHz
Microphone Phantom Power: +48V (software enabled)
Frequency Response: Input – 1Hz to 88kHz
Output – 1Hz to 88kHz
(192kHz hardware sampling rate)
Digital Audio Interface: 2 x AES-3 (formerly known as
AES/EBU) inputs/outputs
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Synchronisation Input: 1 x AES-11 input synchronisation:
Output Sampling Rates: 32kHz, 44.1kHz, 48kHz,
88.2kHz, 96kHz and 192kHz
Input Sampling Rates: 32kHz to 192kHz
Software Sampling Rates: Any rate from 10Hz to 384kHz
Software Resolution: 32, 24, 16 or 8 bits
GPIO Inputs: Optically isolated, 2.5 to 50V on (2.5
to 50mA).
GPIO Outputs: Optically isolated, 5mA max on, 80V
max off.
Connector: 44-pin high-density D-type female
Equipment Type
PC-AD2 2 Stereo analogue I/O & 2 stereo AES-3 I/O
PCIe half height sound card
Physical Specification
Dimensions (Raw): 18cm (L) x 7.0cm (H) x 2cm (D)
7.1” (L) x 2.8” (H) x 0.8” (D)
Dimensions (Boxed): 27cm (L) x 22.5cm (H) x 6cm (D)
10.6” (L) x 8.9” (H) x 2.4” (D)
Weight: Nett: 0.10kg Gross: 0.20kg
Nett: 0.2lbs Gross: 0.4lbs
Accessories
PC-AD2BC PC-AD2 full XLR & 9 pin D-type breakout
cable
PC-AD2SY Cable to sync 2 x PC-AD2 cards