SX-5e SX-6 SX-34 SX-36 Digital Audio Adapter User's Manual September 17, 1999 Rev. E ANTEX ELECTRONICS CORPORATION th 1125 W. 190 STREET GARDENA, CALIFORNIA 90248 info@antex.com www.antex.
Declaration of Conformity Standards to which Conformity is Declared: EN55022 (Class A) 1994, EN 50082-1 1992 This equipment has been verified to comply with the limits for a class A computing device, pursuant to FCC Rules. In order to maintain compliance with FCC regulations, shielded cables must be used with this equipment. Operation with nonapproved equipment or unshielded cables is likely to result in interference to radio and TV reception.
TABLE OF CONTENTS INTRODUCTION ...................................................................... 1 CARD INSTALLATION ............................................................. 1 JUMPER SETTINGS & CONNECTIONS ...................... 2 I/O ADDRESSES AND INTERRUPTS .......................... 3 MAKING CONNECTIONS TO THE CARD ............................... 3 SX-35/36 CONNECTOR DESCRIPTION ................................. 5 SX-34 CONNECTOR DESCRIPTION ......................................
SX-34 MIXER AND BLOCK DIAGRAM......................... 34 SX-6 MIXER AND BLOCK DIAGRAM........................... 36 SX-5e MIXER AND BLOCK DIAGRAM......................... 39 ANTEX METER ........................................................................ 42 TROUBLESHOOTING ............................................................. 46 TECHNICAL/ORDERING INFORMATION: .............................. 49 APPENDIX ...............................................................................
FIGURES Figure 1. SX-5e,6,34,35 & SX-36 Jumper Settings................... 2 Figure 2. SX-35/36 Connections.............................................. 5 Figure 3. SX-34 Connections................................................... 8 Figure 4. SX-6 Connections..................................................... 11 Figure 5. Antex Demo Program ............................................... 23 Figure 6. MPEG Bitrates.......................................................... 24 Figure 7.
INTRODUCTION The Antex SX-5e, SX-6, SX-34 and SX-36 family of cards are ISA bus audio “add-in” cards for the PC. They all incorporate DSP’s (Digital Signal Processors), which allow the cards to do a variety of audio formats. (MPEG, PCM16, MSADPCM, etc.) All cards are dual device, which means they can operate on 2 hard drive files at the same time. These cards operate at several fixed standard sample rates: 8, 11.025, 16, 22.05, 32, 44.1, and 48 KHz.
Set the board number with jumpers as shown below. If only one board is being used, leave the jumpers off (sets to board number one). When using more than one card in a computer, each board must be given a different number by setting the jumpers differently on each card. Any model Antex Card may be used with any other model Antex Card. All model Antex Cards use the same jumper arrangement to set the board number.
I/O ADDRESSES AND INTERRUPTS SX-5e, 6, 34, 35 & 36 I/O addresses and interrupts are software selectable. The valid I/O addresses are: 180h, 220h, 280h, 300h, 320h and 380h The valid interrupts are: 2, 3, 4, 5, 10, 11 and 12 Note that interrupts 3 and 4 are normally used by the computer’s COM ports and will not be available. The interrupt and I/O addresses are selected at the time of software installation or automatically by Windows 95/98.
balanced connections and shielded coax cable for unbalanced connections. See the section “Balanced and Unbalanced Signals”.
SX-35/36 CONNECTOR DESCRIPTION JP4 JP1 JP7 JP3 JP8 BALANCED IN/OUT SX-35/36 JP9 Pin 1 2 3 4 5 6 7 8 Assignment Ground Right In Left InRight Out Left Out Right In + Left In + Right Out + 9 Left Out + Balanced Analog I /O Connector 5 4 3 2 1 DB-9 Female 9 8 7 6 Balanced In - XLR male shell, female pins GND - 2 1 Left + 3 - 2 Unbalanced In - Female RCA 1 Right 5 4 3 2 1 Left + 3 9 8 7 6 Right 1 - 2 5 4 3 2 1 Left 9 8 7 6 + 3 1 Left - 2 Right Right + 3 Balanced Out - XLR female shel
LINE I/0 (JP8) Pin 1 Right Line Input + Pin 3 Right Line Input - Pin 5 Left Line Input + Pin 7 Left Line Input - Pin 9 Right Line Output + Pin 11 Right Line Output - Pin 13 Left Line Output + Pin 15 Left Line Output - Pin 2,4,6,8,10,12,14,16 Ground This connector duplicates the function of the DB9 connector. It might be used with a custom “Industrial Rack Mount PC” with a special cable harness that brought the connections out to the front panel.
AUX IN (JP9) Pin 1 Right Aux Input + Pin 3 Right Aux Input - Pin 5 Left Aux Input + Pin 7 Left Aux Input - Pin 9,11,13,15 No connection Pin 2,4,6,8,10,12,14,16 Ground The Auxiliary inputs are balanced inputs, the same as the Line In and can be used in the same way; as a record source or analog feed-through to the Line Out. MIC (JP7) Pin 1 Microphone input (2.
SX-34 CONNECTOR DESCRIPTION LINE IN JP1 JP5 JP6 JP7 JP4 MIC AUX SX-34 LINE OUT Figure 3. SX-34 Connections 1. SPx Header - JP1 JP1 is a 40-pin, dual-row, 2mm spaced header the provides connections for an SPx module. 2. Output Header - JP5 JP5 is a 5-pin, 0.100" spaced header that provides connections for the left and right output signals. These are the same signals provided by the OUT jack on the bracket. The output signals are switched to JP5 only when the is there no plug in the OUT jack.
3. AUX Header - JP6 JP6 is a 5-pin, 0.100" spaced header that provides connections for left and right auxiliary input signals. These are the same connections provided by the AUX jack on the bracket. Signals present at JP6 are switched in only when there is no plug in the AUX jack. 5 1 Ground Left Input Ground Right Input Ground 4. Microphone Header - JP7 JP7 is a 2-pin, 0.100" spaced header that provides a microphone input connection. This is the same connection provided by the MIC jack on the bracket.
5. Mono Header - JP4 JP4 is a 2-pin, 0.100" spaced header that provides a mono input connection. This input is not currently supported.
SX-6 CONNECTOR DESCRIPTION JP3 JP1 JP4 JP2 BALANCED OUT SX-6 Pin 1 2 3 4 5 6 7 8 Assignment Ground nc nc Right Out Left Out nc nc Right Out + 9 Left Out + Balanced Analog I /O Connector 5 4 3 2 1 DB-9 Female 9 8 7 6 5 4 3 2 1 9 8 7 6 1 5 4 3 2 1 - 2 Left 9 8 7 6 + 3 1 Left - 2 Right Right + 3 Balanced Out - XLR female shell, male pins SX-6 Balanced I/O to XLR Unbalanced Out - Female RCA SX-6 Unbalanced I/O to RCA Figure 4.
LINE OUT (JP2) Pin 1,3,5,7 No connection Pin 9 Right Line Out + Pin 11 Right Line Out – Pin 13 Left Line Out + Pin 15 Left Line Out – Pin 2,4,6,8,10,12,14,16 Ground This connector duplicates the function of the DB9 connector. It might be used with a custom “Industrial Rack Mount PC” with a special cable harness that brought the connections out to the front panel. MICROPHONE INPUT (JP3) Pin 1 Microphone input (2.
SX-5e CONNECTOR DESCRIPTION The SX-5e is self-explanatory. The left and right Line Out connections are RCA jacks on the card bracket, which are labeled. There are no other connectors on the card. BALANCED AND UNBALANCED SIGNALS The SX-5e and the SX-34 have unbalanced signals only. The SX-6 and SX-36 have balanced signals, which can be wired to be connected to unbalanced equipment if desired.
Antex cards are “active”; transformers are not used. Normally, one should not ground the output of an active driver. However the drivers used on the Antex cards are specifically designed to do this and behave identically to a transformer. The main difference between grounding or not grounding the minus output is that grounding the output will boost the output level by 6dB (double the voltage level of the signal).
This is because the input amplifier stages of the card have been overloaded. Also, recording from a source with too low a signal level, such as plugging a microphone directly into a line level input, will result in a very noisy recording. Good signal to noise performance can only be achieved by using a record source with sufficient signal level to register high on the VU meter. Peaks in the red zone should occur occasionally for best signal to noise ratio.
externally, there must be 2 cards installed in the computer, so that there is one physical output for each device. COMPRESSION, DATA RATES, AND NETWORKS The amount of data (the size) of a sound file is affected by several factors. The most obvious is the sample rate. A file recorded at 22.05 KHz will take up half as much disk space as a file recorded at 44.1 KHz. Compression formats also greatly affect the file size. (This is not to be confused with dynamic range compression.
a file, but no fading. Some audio editing programs do edit MPEG files, but they actually convert the file to PCM16 first, and then convert it back again after editing. This has two problems. First, it is slow, and second, each time the conversion is done, the sound quality is degraded. MPEG is only valid for 32, 44.1 and 48 KHz. MPEG requires a great deal of DSP processing power. As a result, the SX-36 can record a 32 KHz MPEG file and play another 32 KHz file back at the same time, but not 44.
tained for a given output bitrate therefore changes with sample rate. In the Antex software the bitrate is specified on a per-channel basis. Therefore, requesting 64 kbits/s and stereo will result in a 128 kbits/s compressed MPEG stream. Supported bitrates (per channel) and compression ratios are as follows: Layer I 32 KHz 44.1 KHz 48 KHz Bitrate (kbits/s) Compression ratio Bitrate (kbits/s) Compression ratio Bitrate (kbits/s) Compression ratio 32 64 96 16 8.0 5.3 32 64 96 128 22.1 11.0 7.4 5.
DRIVER INSTALLATION WINDOWS 95 1. After installing the card, power up the system. 2. Open Control Panel-Add New Hardware applet. 3. Press “Next”. 4. Select “No”. Press “Next”. 5. Select “Sound, video and game controllers”. Press “Next”. 6. Select “Have Disk”. 7. Insert supplied driver diskette into the A: drive, or, point to directory containing the installation files. Click “OK”. 8. Select SX-36 (or other card, as appropriate). Press “OK”. Press “Next”. 9. Press “Finish”. 10.
5. Select “Driver” tab. 6. Select antexwav.vxd, click on “Change Driver”. 7. Select "Have Disk" 8. Point to location of driver files. Click “OK”. Click “OK”. 9. Select antex.drv, click on “Change Driver”. 10. Select "Have Disk" 11. Point to location of driver files. Click “OK”. Click “OK”. 12. Click “OK”. At the prompt for the driver installation disk, point to location of driver files. Click “OK”. 13. Click “OK” to exit the "System Properties" dialog. 14. Reboot to enable the driver.
8. Make sure “Search for a better driver…” is selected. 9. Select the location of the new driver. 10. Click “Next”. Click “Next”. Click “Next”. Click “OK”. 11. Point to location of driver files again. 12. Click “OK”. Click “Finish”. 13. Click “Yes” to reboot the computer. WINDOWS NT 1. After installing the Antex Card in the computer, power the computer back up. 2. From the “Start” menu, select “Run”. In the command line, type “A:\setup”. Insert the DRIVER disk into the “A” drive. Click “OK”. 3.
ANTEX APPLICATION SOFTWARE INSTALLATION The Antex Demo, Mixer, and Meter programs are on a separate floppy disk. The same disk is used for Windows 95/98 and NT. The software installs in the usual manner. 1. Insert the disk into the floppy drive. 2. From the “Start” menu, select “Run”. 3. On the command line, type “A:\setup” 4. Click “OK”. 5. The software will install itself on your hard drive.
USING WINDOWS DEMONSTRATION SOFTWARE Figure 5. Antex Demo Program The Antex Demo program allows basic recording and playback of .WAV files in any of the compression formats available on the Antex audio board you have installed in your system. Sample Rate This list box selects specific sample rates for recording, and displays the sample rate of the file that is currently playing. Not all sample rates are available for each compression format.
Compression: This list box selects specific compression formats for recording, and displays the compressed format of the file currently playing. Note that the Sample Rate and Compression for recording can only be changed when the card is in “Stop” mode. If the card is in “Paused Record”, or is recording, the Sample Rate or Compression will not actually change, even though the dialog box allows you to change them.
Channels: These buttons select mono or stereo recording, and display the number of channels of the current file. VU Meters: The VU meters show the relative signal level of the current file that is being recorded or played. Wave Device: If your driver is configured for dual devices or your computer has more than one Antex audio board, this drop down list box will allow selection of the specific device/board to be used for recording and playback. Each file must be assigned a unique device/board. Figure 7.
File: This button selects a filename for recording or playback. Once this button has been pressed the dialog box in Figure 7 will appear. If you hold down the “Alt” key while clicking on File, the dialog box shown below in Figure 8 will appear. This will allow you to select auto-repeat for playing back a file, or recording for a predetermined amount of time if desired. Figure 8. Auto Repeat Play/Stop: Once a file has been selected, pressing the play button will start the playback.
Volume: These controls allow changing the volume of the playback only. INSTALLING AND USING MULTIPLE CARDS IN A SYSTEM When using more than one card in a system, each card must have a different adapter number. This is set by using the jumpers on top of the card. The Antex Driver must be set up to have a different Address and Interrupt for each card. In Win NT, go to “Start”, “Settings”, “Control Panel”, “Multimedia”, “Devices”, “Audio Devices”, “Audio for Antex Digital Audio Driver”, “Settings”.
Simultaneous Record and Playback MPEG MSADPCM PCM16 SX-34 No 22.05 KHz 48 KHz SX-35 No 22.05 KHz 48 KHz SX-36 32 KHz 32 KHz 48 KHz Dual Device Playback MPEG MSADPCM PCM16 SX-5e 48 KHz 32 KHz 48 KHz SX-6 48 KHz 32 KHz 48 KHz SX-34 44.1 KHz 32 KHz 48 KHz SX-35 44.1 KHz 32 KHz 48 KHz SX-36 48 KHz 44.
and right channels of a stereo signal. Also, only one record device is shown. The small circles with a letter inside correspond between the Mixer Diagram and the Block Diagram. For example, referring to the SX-36 diagrams, the Line In On/Off control, labeled “G” in the Mixer Diagram, is showing that when this control is “On”, the selector switch in the Block Diagram is in the “G” position. In case you are not familiar with some of the symbols used, the triangles with the + and – inside are amplifiers.
“Radio pushbutton” controls G, H, I, and J determine the record source. Only one button on at a time is allowed. It may seem strange that button J will set the record source to Line Out. This is done to allow the use of attenuators C, D, or E to control the record level. Using Line Out as the record source will also allow you to record a mix of all 3 input sources if desired. Note that if buttons G, H, or I are used to select the record source, Sliders C, D, or E will NOT control the record level.
down if the output signal from the Antex card is too loud. One exception to setting both sliders at maximum is when playing 2 files simultaneously. In this case, it may be necessary to lower the sliders slightly to prevent clipping from occurring when peaks of both files occur at the same time. Note that this is a subjective concept; how much degradation of the signal to noise ratio is acceptable depends on the particular situation.
A B A K D C G E H I J Figure 9.
Figure 10.
SX-34 MIXER AND BLOCK DIAGRAM The SX-34 diagrams are the same as the SX-36, with the exception that the SX-34 does not have the Input or Output Trim Controls. D C G E H K I Figure 11.
Figure 12.
SX-6 MIXER AND BLOCK DIAGRAM Output Trim Control B determines the level of the output signal on Line Out which corresponds to digital clipping. If the control is set to +8, the maximum output signal level is +8 dBu. If the control is set to +20, the maximum output signal level is +20dBu. Note that these signal levels correspond to balanced outputs. If the outputs are wired as unbalanced, see the table in the section on “Balanced and Unbalanced Signals” to determine the actual output signal level.
B K L M Figure 13.
Figure 14.
SX-5e MIXER AND BLOCK DIAGRAM Due to the simplicity of the SX-5e, the Antex Mixer does not add control of any features that are not accessible through the Antex Demo. The Play 1 and Play 2 Sliders duplicate the function of the sliders in the Antex Demo program. K L Figure 15. SX-5e Mixer Play 1 and Play 2 Sliders, K, and L control the level of the files being played back. Note that these sliders operate in the digital domain.
and controlling the volume using the master volume control on the external amplifier or mixing board the Antex Card is connected to. One exception to setting both sliders at maximum is when playing 2 files simultaneously. In this case, it may be necessary to lower the sliders slightly to prevent clipping from occurring when peaks of both files occur at the same time. Note that this is a subjective concept; how much degradation of the signal to noise ratio is acceptable depends on the particular situation.
Figure 16.
ANTEX METER The figure below shows a typical Antex Meter window. This can be opened by running “meter.exe” or double-clicking on the meter icon. The size of the window can be changed by dragging the side, bottom or corner of the window. The meter is similar to the meter in the Antex Mixer or Antex Demo, but is much more flexible. It also may be used in conjunction with third party software applications.
If you right-click or double-click on the meter window, the following window will pop-up: Figure 18.
Clicking on “Options” will open the following window: Figure 19. Antex Meter options “Visible Lines” allows you to select which devices have VU meters displayed. “Mode” allows you to select whether the meter is peak reading or averaging (VU). “Peak Hold Level” will keep the peak level lit for the time indicated. “Headroom Indicator” determines where the 0dB point is. The default of zero sets the 0dB point equal to the digital clipping level.
“Meter Update Interval” determines how often the meter program reads the level data from the Antex Card. Note that even if the meter is in peak mode, peaks which occur in between the update intervals will be missed. To avoid this, the update interval should be 5 ms or less. Once the meter is set the way you want, you can save and recall these settings using the “Save/Restore Settings” menu selection.
TROUBLESHOOTING I get an error message when trying to run the Antex Demo program. 1. Card did not install correctly because of an I/O or interrupt conflict. In Win NT, go to “Start”, “Settings”, “Control Panel”, “Multimedia”, “Devices”, “Audio Devices”, “Audio for Antex Digital Audio Driver”, “Settings”. In this dialog box, make sure the correct model Antex Audio Card is selected, and try changing the Interrupt number and/or Address. In Win 95/98, go to “Control Panel”, “System”, “Device Manager”.
Files I record sound “dull”. 1. Use a higher sample rate. Lower sample rates reduce the high frequency content, making recordings sound dull. There is a lot of noise or hum, even when the Antex Card is idle. 1. There may be a wiring problem. Make sure the shields are grounded, especially with unbalanced connections. Don’t run cables close to hum producing equipment, such as transformers. 2. Don’t run unbalanced connections long distances. Generally, unbalanced is OK for less than 6 feet.
too hot. To see if this is the problem, does the Line Out sound distorted when just listening to the record source as a feedthrough? Files recorded are of poor quality. 1. Some formats, bitrates, and sample rates do not sound as good as others. PCM8 should not be used. It is provided only for backward compatibility. Record PCM16 at 48 KHz sample rate as a benchmark; this is the highest quality the card is capable of.
• If using several cards in a system, try just playing one file on one card. If this solves the problem, your system may not be fast enough to handle as many cards and files at once as you want. Using compressed file formats will reduce the amount of data required by each card. TECHNICAL/ORDERING INFORMATION: If you have any questions concerning the operation of your board, or would like to place an order, please contact us at: ANTEX ELECTRONICS CORPORATION th 1125 W.
APPENDIX Connectors for Male Headers For connecting to the auxiliary connectors on the Antex Card, there are 2 types of connectors to use. One type is the individual crimp type, such as the Molex C-Grid series. For single row headers, the part number would be 50-57-900X, where X is the number of contacts. For dual row headers, the part number would be 22-55-2XX1, where XX is the number of contacts. The crimp contacts are ordered separately, 16-02-0103. These parts are available from Digi-Key, www.digikey.
milliwatt into 600 ohms, which is .775 volts RMS. dBV uses 1 volt RMS as the reference. Digital Clipping Digital clipping is the point where the Analog to Digital converter becomes saturated. The signal is “all ones”. For a 16 bit system, this is a value of +32768 or –32768. Digital clipping sounds nastier than analog clipping because of its abruptness. It has no region where the distortion increases progressively.
Specifications Unless otherwise noted, THD+N and Dynamic Range measurements are done at 1KHz, A weighting, 48 KHz sample rate. Maximum input and output levels are for digital full scale. All Cards (as applicable): Sample rates ............................ 8, 11.025, 16, 22.05, 44.1, 48 KHz Frequency Response ...............................20Hz to 20KHz, +/- .5dB Mic input level...............................................................10mV RMS Mic input impedance.........................................
SX-34: THD+N ........................................................................... .02% max Dynamic Range ............................................................... 80dB min Line Out level ....................................................................1V RMS Line Out load impedance (90Hz to 20KHz, -3dB) .........8 ohms min Line Out load impedance (20 Hz to 20 KHz).............. 2K ohms min Line In/ Aux In level ...........................................................
SX-5e: THD+N ....................................................................................02% Dynamic Range ............................................................... 85dB min Line Out level .....................................................................2VRMS Line Out output impedance............................................... 50 ohms Line Out load impedance...........................................
In essence, digital audio is a technological process whereby an analog audio signal (produced when sound waves in the air excite a microphone) is first converted into a continuous stream of numbers (or digits). Once in digital form, the signal is extremely immune to degradation caused by system noise or defects in the storage or transmission medium (unlike previous analog systems).
Figure 20. Analog-to-Digital To visualize the analog-to-digital conversion process, refer to Figure 20. At the top is one cycle of an analog input signal wave. We've used a simple sine wave to make visualization easier. In this example, the signal has a peak-to-peak amplitude of 20 units, measured by the scale on the left. The sampling frequency is many times higher than the signal being sampled and is shown along the bottom of Figure 20.
Digital-to-analog conversion (used in playback) is the exact opposite of the analog-to digital conversion process and is illustrated in Figure 21. In digital-to-analog conversion, the PCM bitstream is converted at the sampling frequency to a continuously changing series of quantization levels which are individual "steps" of discrete voltage equal to the quantization levels in the analog-to-digital process.
The foregoing is a very brief and, of necessity, oversimplified explanation of how digital audio works. For the interested reader, the book Principles of Digital Audio by Ken C. Pohlmann, copyright 1985 by Howard W. Sams, is highly recommended.
