Upgrading and Repairing PCs

Who's Who in Audio

Because audio adapters have become common features in systems, many vendors have produced audio adapters, audio chips, integrated motherboard chipsets with audio features, and even specialized vacuum tube audio. This section examines some of these companies and their products.

As you've learned in other chapters, I believe it is very important to get all the technical information you can about your computer and its components. By knowing who makes the audio chip your computer depends on, you can find out what the hardware can do and be better able to find upgrades to the software drivers you need to get the most out of your audio hardware.

Chipset Makers Who Make Their Own Audio Adapters

Just as graphics card vendors are divided into two camps, chipset makers are divided into these two categories:

• Card makers who produce their own chipsets

• Card makers who use chipsets from other vendors

Audio adapter vendors fall into the same categories. One of the pioneers of the audio adapter business, Creative Labs, has also been among the leaders in developing audio chips. Creative Labs develops audio chips primarily for its own Sound Blaster–branded products, but it has sold some of its older Sound Blaster 16 products into OEM markets.

Creative's major audio chips have included the following:

• Vibra-16. This was used in the later Sound Blaster 16 cards; it doesn't support wavetable or 3D effects.

• Ensoniq ES1370 series (ES1370/71/73). These were used in the Sound Blaster PCI64 and PCI 128 series as well as the Ensoniq Audio PCI and Vibra PCI series. They support soft wavetable features, four speakers on some models and Microsoft Direct 3D but don't support 3D acceleration or EAX positional audio.

• EMU-8000. This audio chip was used by the AWE32/64 series and features 32-voice wavetable synthesis but no 3D acceleration. The AWE64 used software to generate 32 additional voices for a total of 64 voices.

• EMU10K1. This audio chip was at the heart of the Live! and Live 5.1 series sound cards as well as the PCI 512; it features 3D acceleration, EAX positional audio for one audio stream, a reprogrammable DSP, and soft wavetable support.

• EMU10K2 (also known as Audigy). This is the audio chip at the heart of Creative Labs' Sound Blaster Audigy series sound cards; it features 3D acceleration, EAX HD positional audio for up to four audio streams, a reprogrammable DSP, and soft wavetable support. This chip supports professional-level 24-bit sampling at 96KHz and real-time sampling at Dolby Digital–quality 24-bit samples at 48KHz.

• CA0102 (also known as Audigy 2). This audio chip is the one used by the Creative Labs Audigy 2 series. It's a development of the EMU10K2 chip, adding support for 24-bit 96KHz output, Dolby Digital EX 6.1 decoding and 6.1 sound in DirectX games, and 64 hardware polyphonic voices.

Another major player is Philips, which bought chipset maker VLSI and integrated it into its Philips Semiconductor operation in mid-1999. Philips introduced its line of audio adapters in the fall of 2000, using the ThunderBird chipsets it jointly developed with Qsound Labs, Inc. These include the following:

• ThunderBird Q3D (SAA7780). Features 3D audio acceleration of up to 64 3D streams in hardware, positional 3D audio supporting EAX and Qsound standards, quadraphonic speaker support with virtual surround sound, wavetable, and DOS Sound Blaster emulation; it is used by the original Philips Rhythmic Edge (PSC702) and Seismic Edge (PSC704) audio adapters. Third-party audio cards using this chip include the Aztech PCI-368DSP, I/O Magic MagicQuad 8, and Labway Thunder 3D.

• ThunderBird Avenger (SAA7785). Features 3D audio acceleration of up to 96 3D streams in hardware, positional 3D audio supporting EAX and Qsound standards, support for Dolby Digital 5.1, wavetable, and DOS Sound Blaster emulation; it is used by the Philips Seismic Edge 5.1 (PSC705), Rhythmic Edge Surround (PSC703), Acoustic Edge (PSC706), PSC605 Sonic Edge (PSC605), and Dynamic Edge (PSC604) audio adapters.

Both of these highly regarded chipsets are offered as OEM products, but so far only the Q3D/SAA7780 chip has been used by third-party audio card vendors.

Various other companies have produced their own sound chips in the past but no longer do so. The two primary makers that fit in this category are

• Aureal. Its A3D technology was regarded by many as superior to Creative Labs' original EAX 3D positional audio, but the company was absorbed by Creative Labs in mid-2000. Because Creative's new EAX HD is superior to A3D, there will be no further development of this technology.

• Yamaha. Its OPL2 and OPL3 chips were among the best FM-synthesis chips used on older sound cards, and its MIDI performance in later models was outstanding. However, its emphasis is now on MIDI daughtercards and professional sound-recording cards such as the SW1000XG. Some of its retail and OEM products might still be available, though. Yamaha maintains drivers and support links for its branded and some OEM cards at www.yamaha.co.jp/english/lsi/us.

Should you panic if your favorite audio adapter is an "orphan"? Not necessarily. If the audio adapter vendor provides good technical support and up-to-date drivers, you're okay for now. But, the next time an operating system update or new audio API shows up, you probably won't be able to take advantage of it unless you replace your audio adapter.

Major Sound Chip Makers

Most companies other than Creative Labs and Philips depend on third parties to make their audio chips. Some of the major vendors include:

• Cirrus Logic/Crystal Semiconductors. The top-of-the-line Sound Fusion CS4630, an enhanced version of the CS4624, features 3D acceleration, support for both EAX and Sensaura positional audio, unlimited-voice wavetable synthesis, and S/PDIF support for AC3 and Dolby 5.1 input and output at rates up to 48KHz. The CS4630 is used in the popular and highly rated Hercules Game Theater XP, Voyetra Turtle Beach Santa Cruz, TerraTec SiXPack 5.1, Video Logic Sonic Fury, and SonicXplosion audio adapters. The CS4624 is used by the Hercules GameSurround Fortissimo II/III 7.1, Hercules DigiFire 7.1, TerraTec DMX Xfire, and Hoontech SoundTrack I-Phone Digital CS audio adapters.

  Other Sound Fusion series chips include the CS4614 (obsolete) and CS4624 (added), both of which feature support for 3D Direct Sound positional audio, DOS Sound Blaster emulation, and wavetable synthesis.

• ESS Technology. The Canyon3D-2 (ESS1990/1992) is ESS Technology's flagship audio chip, featuring four-channel analog output, support for Dolby and THX digital sound, SPDIF input and output, and Sensaura 3D positional audio, and it is optimized for use with DirectX 8.0. It is used by the I/O Magic Hurricane Extreme, Diamond Monster Sound 3D, Hercules MaxiSound Fortissimo, and TerraTec DMX audio adapters.

  The Maestro-2 series features wavetable, positional 3D from Sensaura, and 3D audio acceleration; the Maestro 2E and 2EM also support S/PDIF output for DVD movie support. The Maestro series chips are optimized for notebook computers, and Maestro chips are used in recent models of Dell, Toshiba, Gateway, Compaq, and HP portables.

  The Allegro series (ESS-1989 for desktops and ESS-1988 for notebook computers) features DirectSound, Direct3D, S/PDIF output, and Sensaura 3D positional sound. The ESS-1989 is used by the Philips Harmonic Edge (PSC602) sound card as well as models sold by Pine Technologies and others.

  ESS's earlier AudioDrive series was popular with many notebook computers and second-tier sound card makers in the mid-1990s.

• C-Media Electronics. The CMI 8738 features 4.1 and 5.1 speaker support for quadraphonic and Dolby Digital output, Direct Sound 3D and A3D positional audio, and wavetable and is available for desktop or notebook computers; some versions also integrate a software modem and SDPIF port. It is used by sound cards such as Guillemot's MUSE and Leadtek's WinFast 4x Sound; some generic sound cards; and motherboards made by Asus, Soyo, and others.

• ForteMedia, Inc. The FM-801 is the first audio chip to feature Dolby Digital 5.1 output to analog speakers for both DVD movies and games. The FM-801 also features Qsound's Q3D 2.0 3D API and optional support for SPDIF input/output. The FM-801 is used by many smaller sound card makers and some motherboard makers, such as Shuttle. For a review of the sound chip and a feature comparison of some sound cards using this chip, see www.3dsoundsurge.com/reviews/FM801/FM801.html.

• Realtek. Although it's better known for low-cost Ethernet network card chipsets, Realtek also offers audio chipsets, including the ALC650, which was introduced in March 2002. The ALC650 is the first motherboard integrated chipset to support AC '97 audio along with six-channel output, Dolby Digital 5.1, stereo, and surround sound. It is featured on high-performance motherboards made by MSI, Giga-byte, Asus, AOpen, and others.

Discontinued and Orphan Sound Chips and Sound Card Producers

The following sound chips are no longer being sold, and ongoing support is limited or no longer available. If you use an audio adapter based on one of these products, you might need to upgrade if you can't get drivers for new and forthcoming operating systems.

Discontinued products include

• Oak Technology OTI-601 series. Oak left the audio chipset business in early 1998.

• Trident 4DWave-NX series. This 3D audio chipset is still available on cards from smaller audio adapter vendors, such as Aztech, Jaton, and Hoontech.

Diamond Multimedia, which used sound chips from several vendors, no longer produces sound cards since its parent company, S3, relaunched itself in the fall of 2000 as an Internet appliance and MP3 audio-focused company called SONICblue. SONICblue still offers limited support for Diamond-brand audio cards, but ongoing driver development is no longer taking place.

Motherboard Chipsets with Integrated Audio

The Intel 810 chipset was the first mainstream chipset for a major CPU to integrate audio; it works with Celeron CPUs. Its inspiration might have been the Cyrix/National Semiconductor Media GX series, which used a trio of chips to substitute for the CPU, VGA video, onboard audio, memory, and I/O tasks.

Thanks to improvements in chipset design and faster CPU performance, today's best integrated chipsets can provide solid mid-range performance. Almost all recent chipsets from Intel, VIA, ALi, and SiS have integrated audio (see Chapter 4, "Motherboards and Buses," for details). In almost every case, integrated audio supports the AC'97 audio standard.

AC'97 Integrated Audio

The phrase AC'97 integrated audio can be found in the descriptions of most recent systems. Because AC'97 can replace the need for a separate audio card but might not be a satisfactory replacement, you need to understand what it is and how it works.

AC'97 (often referred to as AC97) is an Intel specification that connects an audio codec (compression/decompression) architecture to a section of a South Bridge or an I/O Communications Hub chip called the AC-Link control. The AC-Link control works with the CPU and an AC '97 digital signal processor (DSP) to create audio.

The AC'97 audio codec could be a physical chip on the motherboard, a chip on a small daughterboard called a communications and networking riser (CNR), or a software program. Thus, a motherboard with AC '97 integrated sound support doesn't require the use of a separate audio card for sound playback. Sometimes AC'97 is also used to refer to audio chips on a sound card, but in this discussion we will use it to refer only to integrated audio. Sometimes motherboards also integrate an analog modem through an MC '97 codec chip, or they might have an AMC '97 (audio/modem) codec chip to combine both functions.

It's important to realize that, although most recent chipsets support AC'97 audio, this does not mean that every motherboard built on a particular chipset uses the same AC'97 codec, or even the same method of creating sound. In most cases, AC'97 is implemented through a small AC'97 codec chip on the motherboard (see Figure 16.8). It can be surface-mounted as shown in Figure 16.8, but many vendors use a small socket instead.

For various reasons, including features and price, different motherboard vendors might use different AC'97 codec chips on motherboards that use the same chipset.

For example, compare the following motherboards based on the Intel 815E-series chipsets as listed in Table 16.3.

Table 16.3. AC'97 Codecs Used with Intel 815E–Based Motherboards

Vendor	Motherboard Model	AC'97 Codec Chip
Intel	D815EPFV	Analog Devices AD1885 (SoundMax)
Giga-Byte	GA-6IEM	Realtek (probably ALC-650)
Kontron	786Flex-8145	Crystal CS4299

The drivers for a particular AC'97 codec chip are supplied by your motherboard vendor because they must be customized to the combination of codec and South Bridge/ICH chip your motherboard uses.

Although the AC'97 specification recommends a standard pinout, differences do exist between AC'97 codec chips. Some vendors of AC'97 chips provide technical information to help motherboard builders design sockets that can be used with different models of the AC'97 codec chip.

The four versions of the AC'97 codec are as follows:

• AC'97 1.0. Has fixed 48KHz sampling rate and stereo output

• AC'97 2.1. Has options for variable sampling rate and multichannel output

• AC'97 2.2. Has AC'97 2.1 features plus optional S/PDIF digital audio and enhanced riser card support; released in September 2000

• AC'97 2.3. Has AC'97 2.1/2.2 features plus support for true Plug and Play detection of audio devices; released in July 2002

Most motherboards with integrated audio support AC'97 2.1 or 2.2 at this time. To learn more about the AC'97 specifications, see the Intel – Research and Development, Audio Codec site at www.intel.com/labs/media/audio/index.htm.

To determine whether a particular motherboard's implementation of AC'97 audio will be satisfactory, follow these steps:

AOpen TubeSound

The Taiwan-based motherboard maker AOpen, part of the Acer Group, came up with a very interesting gimmick in June 2002 when it introduced the world's first PC motherboard with a vacuum tube–based audio amplifier—the AOpen AX4B-533 Tube. The motherboard was based on the Intel 845E chipset, and uses a Realtek ALC650 AC97 sound chip. At first, many PC users wondered whether this was an April Fool's joke that showed up late. Why a vacuum tube? AOpen engineers pointed out that serious audiophiles have continued to use vacuum-tube amplifiers because of their rich sound. They felt that audiophiles would pay a premium price for similar technology in the sound circuitry of a PC. AOpen used the following design features to bring the vacuum tube into the twenty-first century:

• A switching mode power supply to provide adequate tube power. Tubes fell out of favor in the late 1950s because they require more power than transistors and integrated circuits.

• A dual-triode. This design has one tube with two front stereo channels and is modeled after the design used by classic pre-amp circuits, which can also accept input from standard sound cards.

• Frequency isolation wall (FIW) noise reduction. This shields the tube circuitry from the normal EFI/RFI interference inside the computer.

• High mean time between failure (MTBF) design for motherboard and tube circuitry.

The AX4B-533 Tube is among the most expensive motherboards using the 845E chipset, selling for about $160–$190 compared to about $100 for other models (see Figure 16.9). However, it has received rave reviews from many computer publications and users for audio quality, performance, and (not least) the snob appeal of having the first motherboard on the block like it.

The AX4B-533 Tube's audio quality is optimized for classical and jazz music listening. AOpen has now released two additional vacuum-tube-based motherboards: the AX4GE Tube and AX4PE Tube, which are optimized for rock and pop music thanks to a slightly revised tube and amplifier design.

Tip To compare these motherboards in more detail, see the AOpen TubeSound technology Web site at www.aopen.com/tech/techinside/Tube.htm.