M-audio 24 BIT FLYING COW user guide

Table of Contents

FCC Class B and CE Compliance ........................................... 2

Overview..................................................................................... 3

Features ....................................................................................... 4

D/A Converter .................................................................... 4

A/D Converter .................................................................... 4

Front Panel ........................................................................... 4

Panels - Fig. 1.............................................................................. 5

Panel Description....................................................................... 6

Front Panel ........................................................................... 6

Rear Panel ............................................................................ 7

Installation and Typical Setup ................................................. 8

Typical Setup - Fig. 2 ................................................................ 9

Operation ................................................................................. 10

Selecting Modes ................................................................ 10

D/A Operation .................................................................. 10

A/D Operation .................................................................. 11

Troubleshooting ...................................................................... 14

Appendix A - Specifications ................................................. 16

Appendix B - Diagnostics ..................................................... 17

Appendix C - Block Diagram ............................................... 18

Appendix D - Grounding ..................................................... 19

Lifetime Limited Warranty..................................................... 20

24 Bit Flying Cow

™

MANUAL

1

Version COW20- 080699

2

FCC Class B and CE Compliance

WARNING: This equipment has been tested and found to comply with
the limits for a CLASS B digital device, pursuant to Part 15 of the FCC
Rules. These limits are designed to provide reasonable protection against
harmful interference in a residential installation. This equipment gener­ates, uses and can radiate radio frequency energy and, if not installed
and used in accordance with the instructions contained in this manual,
may cause harmful interference to radio and television communications.
However, there is no guarantee that interference will not occur in a par­ticular installation.

If this equipment does cause harmful interference to radio or television
reception, which can be determined by turning the equipment off and
on, the user is encouraged to try to correct the interference by one or
more of the following measures: 1) reorient or relocate the receiving
antenna; 2) increase the separation between the equipment and the
receiver; 3) connect the equipment into an outlet on a circuit different
from that of the receiver; 4) consult the dealer or an experienced audio
television technician.

NOTE: Connecting this device to peripheral devices that do not
comply with CLASS B requirements or using an unshielded
peripheral data cable could also result in harmful interference to
radio or television reception.

The user is cautioned that any changes or modifications not expressly
approved by the party responsible for compliance could void the user’s
authority to operate this equipment.

To ensure that the use of this product does not contribute to interference,
it is necessary to use shielded I/O cables.

This product also complies with European CE requirements.

3

Overview

Thanks for choosing the Flying Cow, professional external digital
audio converter box. The unit provides high quality, 24-bit A/D
and D/A converters and supports the popular digital audio for­mats S/PDIF and AES/EBU. The Flying Cow’s unique design
allows it to fit into half of a standard 19” rack space — two Flying
Cows may be mounted side by side in a single 19” rack space!

The Flying Cow is a perfect companion for computer digital I/O
cards, or any other digital audio device that requires high-quality
A/D and/or D/A conversion. It can even be used as a replace­ment for lower performance DAT or DVD converters.

This manual assumes that you have a basic understanding of
A/D and D/A conversion, and digital audio. If after reading this
manual you need additional technical support or if you have
comments or suggestions, we invite you to contact us directly by
any one of the following methods:

MIDIMAN

45 E. Saint Joseph Street
Arcadia CA 91006-2861

Technical Assistance: [phone]
Fax: [phone]
Sales: [phone]
Internet Tech Support: [e-mail]

Internet:

Web Site: http://www.midiman.net
Tech Support: [e-mail]
Sales Info: [e-mail]

4

Features

• Pro quality, stereo A/D and D/A converters.

• Simultaneous A/D and D/A conversion.

• Standard single height, half-rack dimensions.

• AES/EBU digital I/O on XLR connectors.

• S/PDIF digital I/O on RCA connectors.

• Balanced analog inputs on either XLR or 1/4”
tip-ring-sleeve connectors.

• Unbalanced analog inputs on 1/4” tip-sleeve connectors.

• Balanced analog outputs on XLR connectors.

• Unbalanced analog outputs on 1/4” connectors.

D/A Converter

• 24-bit stereo D/A, delta-sigma converters with
128x oversampling.

• Dynamic range of 104dB (A-weighted).

• THD = 0.001% @ 0dBFS.

• Frequency Response:† 20Hz-22kHz, -0.5,-0.3dB

A/D Converter

• 24-bit stereo A/D, delta-sigma converters with
128x oversampling.

• Dynamic range of 102dB (A-weighted).

• THD: 0.0015% @ 0dBFS.

• Frequency Response:† 20Hz-20kHz, -0.5,-0.3dB.

• Sample Rates:† 32, 44.1, 48 kHz and "EXT".

Front Panel

• Analog Input Level knob allows optimum gain setting of
input signal to A/D.

• Dual LED level ladders accurately depict incoming signal
levels to A/D.

• A/D sample rate adjustable from front panel.

• “D/A Valid” LED indicates valid incoming digital data.

• LEDs indicate current digital format and A/D sample rate.

• Unit remembers system setup even after power-off.

5

Panels - Fig. 1

POWER

D/A

V

ALID

D

IGITAL

FORMAT

AES/

EBU

S/P

DIF

48

32

EXT

44.1

MODE

SELECT

A/D I

NPUT LEVEL

ANALOG

INPUT L

EVEL

A/D

SAMPLE RAT E

L

R

-40 -20

-10 -6

-3

CLIP

0

MAX

ANALOG OUT

L

R

ANALOG IN

AES/EBU

OUT

S/PDIF

AES/EBU

IN

L

R

9VAC

OUT

IN

1.

2.

3.

4.

5.

6.

7.

8.

11.

14.

12.

13.

9.

10.

FLYING COW

™

AUDIO

1

24

BIT

6

Panel Description

Front Panel

1. D/A Valid: This LED indicates valid incoming digital data for
the D/A converter. When in AES/EBU mode, this LED lights
whenever there is a valid digital signal present at the
AES/EBU In jack. When in S/PDIF mode, this LED lights
whenever there is a valid digital signal present at the S/PDIF
In jack.

2. Digital Format: These two LED’s indicate the current digital
interface mode as either AES/EBU (professional) or S/PDIF
(consumer). The mode applies to digital data both entering
and exiting the Flying Cow. The Digital Format is selected via
the Mode Select Button.

3. A/D Sample Rate: These four LED’s indicate the current sam-
ple rate in use by the A/D converter (48kHz, 44.1 kHz, 32
kHz, or EXT). The first three are standard sample rates. EXT
is a special mode in which A/D conversion is synchronized
with the sample rate of some external source. It is often used
to sync with less common and non-standard sample rates.

4. Mode Select: Repeatedly pressing this button will cycle
through all of the available sample rates and digital formats.
When powered up, the Flying Cow will restore the mode and
sample rate that was set before the previous power-down.

5. A/D Input Level LED’s: These LED meters indicate the left
and right analog audio levels entering the A/D converter.
CLIP indicates an overload condition to the A/D channel and
will result in distortion.

6. Analog Input Level: This knob sets the level of the incoming
analog audio signal as it enters the A/D converter. For the
greatest dynamic range (and signal-to-noise ratio), it is best to
set these levels as high as possible without making the CLIP
LED’s light. When turned all the way down (0) attenuation is
full, and when turned all the way up (Max) gain is maximum.

7. Power: When this button is in, power is applied to the unit.
When out, power is off. When power is turned off, the Digital
Format and A/D Sample Rate settings are saved, and restored
upon power up.