/ Audio

The Legendary Sound Blaster

Creative Labs propelled the home PC industry into a future where sound is seriously considered. In this article, I'll be sharing some of the history behind the Sound Blaster, why it was important, and pitfalls to remember when purchasing old models today.

Note: This will be a constantly updated post as new information becomes available.

Ad Lib

In the late 80s, IBM PCs (and their compatible clones) didn't make a whole lot of sound beyond the little internal PC speaker. In 1987, a Canadian company called Ad Lib, Inc. released a sound card named after the company itself. (Or perhaps, the company was named after their product. Will we ever know?)

The AdLib card contained an FM synthesis chip for producing rich timbres. The chip is the OPL2, designed by Yamaha. When people talk about how DOS game music sounded, they're almost always talking about this chip if it's not a digital soundtrack. There isn't much more to the AdLib, and it could even be built from off-the-shelf parts.

In 1989, Creative Labs released the very first Sound Blaster card. It was 100% compatible with the AdLib, and added "DSP" functionality which allowed programs to output digitized sound effects and music. The card became an immediate success and paved the way for Creative's dominance within the home PC sound card market. Ad Lib, Inc. could not keep up with their own offerings and, in 1992, despite being the inspiration for the whole thing, went bankrupt.

Features

Bugs

Creative's cards were known for being buggy in certain circumstances.

MPU-401 Hanging Notes

There is abundant information about the hanging note bug, which causes MIDI playback trouble for Sound Blaster 16 and (AWE)32 cards. Vogons user James-F claims the hanging notes apply to all MPU-401 interfaces. When this bug occurs, notes will occasionally continue to play after they were supposed to have stopped playing.

MPU-401 High Pitched Ringing

Under these conditions, high pitched ringing will play randomly:

  • DSP version must be 4.11, 4.12, or 4.13
    • Cards older than the Sound Blaster 16 have DSP numbers less than 4 and are unaffected
  • Digital sound must be playing
  • Either a Waveblaster daughterboard or external MPU-401 interface must be in use
  • A discrete OPL chip (YMF262 or YMF289) must be present on the card

The high pitched ringing is bad enough that affected cards should have their Waveblaster capability considered useless.

MPU-401 Stuttering

Music playback will stutter if the MPU-401 interface is used while digital audio at greater than 11khz is being played in some circumstances. Build engine games are especially succeptible.

Clicks and Pops During Digital Audio

A particular method of digital audio playback called "Single-cycle DMA Mode" causes clicks and pops on all Sound Blaster 16 cards that do not have a Vibra chip onboard. It isn't particularly noticeable when there's a lot of sound going on, but it is still audible.

Ringing or Hissing After Digital Audio

On cards utilizing the Vibra chip, a faint ringing or hissing may be heard after digital audio stops playing.

Not Actually Bugs

Occasionally, there will be differences among the cards and the way they were programmed that were, for a long time, misunderstood.

Reverse Stereo

Recent research on the Vogons forums led by user James-F has proven that the widespread "reverse stereo bug" is actually poor implementation by many software developers. That's not a hardware bug in the Sound Blaster, but some clone cards (including cards with Aztech and Yamaha chipsets) try incorrectly to compensate by swapping the left and right digital audio channels to make up for how the software was written.

Filter Cutoff on Digital Audio

Sound Blaster cards before the Sound Blaster 16 have a fixed low-pass filter to reduce the effects of aliasing, which sounds like metallic overtones when playing samples at a low sampling rate.

The Sound Blaster 16 has a dynamic filter which adjusts its cutoff frequency. This means samples playing at a lower sample rate will have a lower filter. This also means lower sample rate audio will sound more muffled than it did on earlier Sound Blasters. Whether this sounds better or worse is a hot debate topic, and seems to be entirely subjective.

Creative's "CQM" OPL Clone

At some point during the transition from manufacturing Sound Blaster 16 and AWE32 cards, it was decided within Creative to clone the Yamaha OPL3 chip they'd been using for FM synthesis called Creative Quadratic Modulation. I suspect it was a cheaper alternative to repeatedly licensing Yamaha's design.

Cards that are third generation (Sound Blaster 16) or newer that contain the CT1978 chip have CQM. If it's as new as a Sound Blaster AWE64 and still supports FM synthesis, then it contains the CQM regardless.

A demonstration of the difference in sound exists on Wikipedia.

Master List

This list is a work in progress. More data to come later.

Multiple Cards Sharing CT Numbers

There can be multiple variants of the same CT board, which may have different capabilities. In these cases, the base chipset is mostly identical. The CT2230 is one such example: note the differences in whether CSP is socketed or soldered, and which CD interfaces are present. When buying, be wary and always verify with photos.

Since the Sound Blaster 2.0, additional identifying codes were added to Sound Blaster cards. A six digit code on the lower-left corner of the card will identify which revision of the card it is. These cannot be used to uniquely identify cards, however. The CT1750 and CT1770 both share one such code.

It seems the first two digits are the revision number (starting at 01), the next two digits are the year, and the final two digits are the week number (1-52). This date supposedly indicates when the PCB was designed.

CT1730/CT1740

I could not locate any cards that have CT1730 printed on the board itself. However, some CT1740 boards have CT1730 printed on their model sticker. It's unclear whether to assume that these two models are identical. It is suggested that the CT1730 is really the CT1740 with a low version DSP. Revision 049251 is known to have the CT1730 sticker and v4.05 DSP. Vogons user Boxpressed claims revision 059334 is also this way.

CT2770

This card is a curiosity: revisions 01 and 03 use what appears to be the same PCB, but revision 02 looks completely different. Additionally, revision 01 has a later code date than revision 03. This is one specific model that goes against many of the "rules" of numbering. Despite all this, all revisions use the exact same chipset.

CT2940

Even among cards of the same revision, some of them have the CT1978 CQM and some of them have a legitimate YMF289B-S OPL3. Be on the lookout whenever you come across these cards. The ones with the true OPL3 chip seem to be quite a bit more rare.

DACs

DACs convert digital audio signals to analog audio signals, suitable for output. Later DACs tend to improve fidelity and reduce noise in the signal. Vogons user James-F reports on quality for all DACs.

In order of highest quality to lowest quality:

  • CT1703-A
  • CT1703-TBS
  • CT1703-T
  • CT1701

Synths

Synths include all processors involved in generating both sound and music. It's safe to assume all synths are entirely Creative's own, except the following:

  • CT1747 (Creative DSP with licensed Yamaha OPL3)
  • SAA1099 (Philips SAA)
  • YM3812 (Yamaha OPL2)
  • YM262-M, YMF-278, YMF-289 (Yamaha OPL3)

Functionality

  • DSP units
    • CT1321: version 2.xx
    • CT1341: version 3.xx
    • CT1351: version 2.xx (SB 2.0)
    • CT1741: version 4.xx
  • PCM units
    • CT1321: SB 1.0 (integrated DSP)
    • CT1336: SB 2.0 & SB Pro
    • CT1345: SB Pro 2.0
    • CT1745: SB 16
  • CT1705: Plug'n'Play controller
  • CT1748: Fully programmable ASP/CSP chip

Features

  • CSP: Socket for CT1748 (may or may not be installed)
  • Goldfinch: Goldfinch (CT1920) add-on header
  • IDE: 40-pin IDE header
  • Joy: 15-pin joystick connector
  • LMSI: LMSI connector
  • Mitsumi: Mitsumi CD-Rom connector
  • Panasonic: Panasonic CD-Rom connector
  • PCSPK: 2-pin PC Speaker header
  • RAM: onboard RAM
  • RCA: white/red RCA audio output
  • SBRAM: AWE64 proprietary RAM expansion slots
  • SCSI: SCSI connector
  • SIMM: standard SIMM RAM expansion slots
  • Sony: Sony CD-Rom connector
  • Vol: volume control via wheel
  • WB: WaveBlaster header
  • WT: onboard wavetable
Game Blaster
ModelRevisionDescriptionChipsetFeatures
CT1300Game BlasterSAA1099 (x2)RCA, Vol
Sound Blaster 1st Generation
ModelRevisionDescriptionChipsetFeatures
CT1310Sound Blaster 1.0, IBACT-SBSAA1099 (x2), YM3812, CT1321Joy, Vol
CT1320ASound Blaster 1.0, IBACT-SBSAA1099 (x2), YM3812, CT1321Joy, Vol
CT1320BSound Blaster 1.0, IBACT-SBSAA1099 (x2), YM3812, CT1321Joy, Vol
CT1320CSound Blaster 1.5, IBACT-SBYM3812, CT1321Joy, Vol
CT1320USound Blaster 1.5, IBACT-SBYM3812, CT1321Joy, Vol
CT1350BREV 4Sound Blaster 2.0, IBACT-SB2YM3812, CT1336, CT1351Joy, Vol
CT1350B049151Sound Blaster 2.0, IBACT-SB2YM3812, CT1336A, CT1351Joy, Vol
CT1350B059316Sound Blaster 2.0, IBACT-SB2YM3812-F, CT1336A, CT1351Joy, Vol
CT5320Sound Blaster MCV, IBACT-SBPMCVYM3812, CT1321Joy, Vol
Sound Blaster 2nd Generation
ModelRevisionDescriptionChipsetFeatures
CT1330REV 4Sound Blaster Pro, IBACT-SBPYM3812 (x2), CT1336, CT1341, CT1345Joy, PCSPK, Vol
CT1330AREV 5Sound Blaster Pro, IBACT-SBPYM3812 (x2), CT1336, CT1341, CT1345Joy, PCSPK, Vol
849-3030Tandy Multimedia Audio Adapter, IBACT-SBPTDYM3812 (x2), CT1341, CT1345, CT1346Joy, Mitsumi, Vol
CT1600039151Sound Blaster Pro 2, IBACT-SBP2PYMF262-M, CT1336, CT1341, CT1345Joy, PCSPK, Vol
CT1600049219Sound Blaster Pro 2, IBACT-SBP2PYMF262-M, CT1336, CT1341, CT1345Joy, PCSPK, Vol
CT1600059234Sound Blaster Pro 2, IBACT-SBP2PYMF262-M, CT1336, CT1341, CT1345Joy, PCSPK, Vol
CT1600069237Sound Blaster Pro 2, IBACT-SB2P2P5YMF262-M, CT1336A, CT1341, CT1345Joy, PCSPK, Vol
CT1600079337Sound Blaster Pro 2, IBACT-SB2P2P5YMF262-M, CT1336A, CT1341, CT1345-SJoy, PCSPK, Vol
CT1610Sound Blaster Pro 2 SCSI, IBACT-SBPSCSIYMF262-M, CT1336A, CT1341, CT1345-SJoy, PCSPK, SCSI, Vol
CT1620Sound Blaster Pro 2 LMSI, IBACT-SBP2LMSIYMF262-M, CT1336A, CT1341, CT1345-SJoy, LMSI, PCSPK, Vol
CT1680039313Sound Blaster Pro 2 OEMYMF262-M, CT1336, CT1341, CT1345-SJoy, PCSPK, Vol
CT1690A019231Sound Blaster Pro 2 Sony, IBACT-SBP2SONYYMF262-M, CT1336A, CT1341, CT1345-SJoy, PCSPK, Sony, Vol
CT2600019310Sound Blaster Pro 2 MitsumiYMF262-M, CT1336A, CT1341, CT1345Joy, Mitsumi, PCSPK, Vol
CT2600029323Sound Blaster Pro 2 MitsumiYMF262-M, CT1336A, CT1341, CT1345-SJoy, Mitsumi, PCSPK, Vol
CT5330039212Sound Blaster Pro MCVYMF262-M, CT1336, CT1341, CT1345, CT5335-127Joy, PCSPK
Sound Blaster 3rd Generation
ModelRevisionDescriptionChipsetFeatures
CT1740049251Sound Blaster 16YMF262-M, CT1701, CT1741, CT1745A, CT1746B-067IDE, Joy, PCSPK, Vol
CT1740059334Sound Blaster 16YMF262-M, CT1701, CT1741, CT1745A, CT1746B-067IDE, Joy, PCSPK, Vol
CT1740069348Sound Blaster 16YMF262-M, CT1701, CT1741, CT1745A, CT1746B-067IDE, Joy, PCSPK, Vol
CT1750019334Sound Blaster 16 Multi-CDYMF262-M, CT1701, CT1741, CT1745A, CT1746B-067Joy, Mitsumi, Panasonic, PCSPK, Sony, Vol
CT1770019334Sound Blaster 16 SCSI-2YMF262-M, CT1701, CT1741, CT1745A, CT1746B-067CSP, Joy, PCSPK, SCSI, Vol, WB
CT1770039352Sound Blaster 16 SCSI-2YMF262-M, CT1701, CT1741, CT1745A, CT1746B-067CSP, Joy, PCSPK, SCSI, Vol, WB
CT1779019334Sound Blaster 16 SCSI-2YMF262-M, CT1701, CT1741, CT1745A, CT1746B-067CSP, Joy, PCSPK, SCSI, Vol, WB
CT1780029321Sound Blaster 16 LMSIYMF262-M, CT1703-TBS, CT1741, CT1745A, CT1746B-067, CT1748AJoy, PCSPK, WB, Vol
CT1790029231Sound Blaster 16, IBACT-SB16SONYYMF262-M, CT1703-TBS, CT1741, CT1745A, CT1746B-067CSP, IDE, Joy, PCSPK, Vol
CT2230029417Sound Blaster 16, SB16L2MCT1703-T, CT1741, CT1745A, CT1747CSP, Joy, Mitsumi, Panasonic, PCSPK, Sony, WB
CT2230049432Sound Blaster 16 MCD CSPCT1703-A, CT1745A-S, CT1747, CT1748AJoy, Mitsumi, Panasonic, PCSPK, Sony, WB
CT2260029430Sound Blaster Vibra 16YMF262-M, CT2501-TBQJoy, PCSPK, WB
CT2290049513Sound Blaster 16CT1703-A, CT1745A-S, CT1747Joy, Panasonic, PCSPK, WB
CT2700019334Sound Blaster 16
CT2740049351Sound Blaster 16CT1703-T, CT1741, CT1745A, CT1747CSP, IDE, Joy, PCSPK, Vol, WB
CT2740059352Sound Blaster 16CT1701-T, CT1741, CT1745A, CT1747CSP, IDE, Joy, PCSPK, Vol, WB
CT2770019423Sound Blaster 16 Value, IBACT-SB16VALCT1703-T, CT1741, CT1745-S, CT1747Joy, Panasonic, PCSPK
CT2770029409Sound Blaster 16 Value, IBACT-SB16VALCT1703-T, CT1741, CT1745-S, CT1747Joy, Panasonic, PCSPK
CT2770039415Sound Blaster 16 Value, IBACT-SB16VALCT1703-T, CT1741, CT1745-S, CT1747Joy, Panasonic, PCSPK
CT2772019432Sound Blaster 16, IBACT-SB16NCDRCT1703-T, CT1741, CT1745A, CT1747Joy, PCSPK, WB
CT2800029509Sound Blaster 16YMF262-M, CT2504-TCQJoy, PCSPK, WB
CT2810019449Sound Blaster 16YMF262-M, CT2501-TDQJoy, PCSPK, WB
CT2830029508Sound Blaster 16CT1701-T, CT1741, CT1745A-TBP, CT1746B-067CSP, IDE, Joy, PCSPK
CT2840019526Sound Blaster 16CT1743-CAP, CT1747IDE, Joy
CT2860029528Sound Blaster 16, IBACT-MENUETYMF262-M, CT2504-TCQJoy, PCSPK, WB
CT2890019518Sound Blaster 16, IBACT-V16SPNPYMF262-M, CT1705-B/CT1705-DCQ, CT2504-TCQIDE, Joy, PCSPK
CT2900019541Sound Blaster 16CT2504-TCQIDE, Joy, PCSPK, WB
CT2910019519Sound Blaster 16, IBACT-SB16PASPCT1703-TBS, CT1741, CT1745A-S, CT1746B-067IDE, Joy, Panasonic, PCSPK, WB
CT2940019529Sound Blaster 16YMF289B-S (some), CT1978-TAP (some), CT2502-SDQIDE, Joy, PCSPK, WB
CT2950019529Sound Blaster 16CT1703-A, CT1741, CT1745A-S, CT1749-DAQ, CT1978-BAPIDE, Joy, PCSPK, WB
CT2950029538Sound Blaster 16CT1703-A, CT1741, CT1745A-S, CT1749-DCQ, CT1978-BAPIDE, Joy, PCSPK, WB
CT2960019547Sound Blaster 16 IBACT-SBPRELUDECT2505-TDQ2Goldfinch, Joy, PCSPK, WB
CT2970019606Sound Blaster 16, HP 5063-9057CT1978-TAP, CT2502-SDQGoldfinch, Joy, WB
CT2980039615Sound Blaster 16, IBACT-SB16PNPSCCT1978-BAP, CT2502-SDQIDE, Joy, PCSPK, WB
PB3110019451Phone BlasterYMF262-M, CT2501-TDQJoy, Modem, PCSPK
CT3180019546Phone BlasterCT1978-TAP, CT2502-SDQJoy, Modem, WB
CT4100019631Sound Blaster 16CT2508-IBTJoy, PCSPK, WB
CT4130019637Sound Blaster 16CT2508-IBTJoy, PCSPK
CT4150019640Sound Blaster Vibra 16CCT2505-TDQ2Joy, PCSPK
CT4170049730Sound Blaster 16CT2511-SATJoy, PCSPK
CT4180029717Sound Blaster Vibra 16CCT2505-TDQ2Joy, PCSPK
Sound Blaster 4th Generation ISA
ModelRevisionDescriptionChipsetFeatures
CT2760019401Sound Blaster AWE32CT1701-T, CT1745A, CT1747, CT1748A, CT1971Joy, Mitsumi, Panasonic, PCSPK, RAM, SIMM, Sony, WB
CT2760039436Sound Blaster AWE32CT1701-T, CT1704, CT1745A, CT1747, CT1748A, CT1971-QJoy, Mitsumi, Panasonic, PCSPK, RAM, SIMM, Sony, WB
CT3600019532Sound Blaster AWE32, IBACT-SB32PNPCT1971-PCQ, CT1972, CT1978-BAP, CT2502-SDQIDE, Joy, PCSPK, SIMM
CT3600029609Sound Blaster AWE32CT1971-PCQ, CT1972, CT1978-TAP, CT2502-SDQIDE, Joy, PCSPK, SIMM
CT3620019539Sound Blaster 32CT1703-A, CT1745A-S, CT1749-DAQ, CT1971-TDQ, CT1972, CT1978-BAPIDE, Joy, PCSPK, SIMM
CT3630029611Sound Blaster AWE32 ValueCT1971-TDQ, CT1972, CT1978-TAP, CT2502-SDQJoy, RAM
CT3640Sound Blaster 32
CT3660019607Sound Blaster AWE32CT1971-TDQ, CT1972, CT1978-TAP, CT2502-SDQJoy, PCSPK, RAM
CT3670Sound Blaster AWE32, SB32PN45
CT3680Sound Blaster AWE32
CT3690Sound Blaster 32
CT3780019434Sound Blaster AWE32 Value, IBACT-SBWEVALCT1703-TBS, CT1741, CT1745A, CT1747, CT1971, CT1972CSP, Joy, Mitsumi, Panasonic, PCSPK, Sony
CT3900019450Sound Blaster AWE32CT1703-A, CT1741, CT1745A-TBP, CT1748A, CT1971, CT1972IDE, Joy, Panasonic, RAM, SIMM, WB
CT3910019502Sound Blaster AWE32CT1703-T, CT1741, CT1745A, CT1747, CT1971-Q, CT1972CSP, IDE, Joy, RAM
CT3930029515Sound Blaster 32YMF262-M, CT1971, CT1972, CT2501-TDQIDE, Joy, PCSPK, SIMM
CT3960019517Sound Blaster AWE32 PnPCT1703-A, CT1705-B, CT1745A-S, CT1747, CT1748A, CT1971-TDQ, CT1972IDE, Joy, PCSPK, RAM, SIMM, WB
CT3980019527Sound Blaster AWE32CT1703-A, CT1705-B/CT1705-DCQ, CT1745A-S, CT1747, CT1748A, CT1971-TDQ, CT1972IDE, Joy, PCSPK, RAM, SIMM, WB
CT3990019531Sound Blaster AWE32CT1703-A, CT1741, CT1745A-S, CT1748-SBP, CT1749-DCQ, CT1971-Q, CT1972, CT1978-TAP
CT4380019635Sound Blaster AWE64CT1703-A, CT1745A-TBP, CT1972, CT8903-DAQIDE, Joy, PCSPK
CT4390019649Sound Blaster AWE64 GoldCT1745A-S, CT8903-DAQ, CT8908-OAT, EMU8011-01Joy, RCA, SBRAM
CT4500029715Sound Blaster AWE64CT1703-TBS, CT1745A-TBP, CT1972-N, CT8903-DAQJoy, SBRAM
CT4520019729Sound Blaster AWE64CT8920-NBQJoy, PCSPK
CT4520029931Sound Blaster 16 WavEffects, IBACT-SB4520A64VCT8920-NBQJoy, PCSPK
CT4540019728Sound Blaster AWE64 Gold, IBACT-SB4540A64GCT1745A-SCF, CT8903-MCQ, EMU8011-01Joy, RCA, SBRAM
Sound Blaster 4th Generation PCI
ModelRevisionDescriptionChipsetFeatures
CT4650009803Sound Blaster AWE64DCT8800-SATJoy, SBLINK
CT4700019833Sound Blaster PCI 1285507-0001-01Joy

Buying Guide

On the Nerdly Pleasures blog, there are a couple great buying guides depending on which generation you seek. Here are the pertinent links:

Conclusion

If you're looking for the ultimate in digital audio compatibility, look no further. Even on my most modern machines, I had no issue getting these cards to work. ISA Sound Blaster cards will be a bit more expensive than their clone counterparts, however.

It's a huge shame about the practically-unusable Waveblaster header on many of the Sound Blaster 16 and (AWE)32 models with a discrete OPL3. But if you don't plan to use a Waveblaster header, these should be your first choice.