General Computer Issues

Most of the hardware market is interested in making cool sound effects for a desktop computer.   The quality control level may be sufficient for a small amplifier and personal speakers, but it is NOT adequate for professional grade audio.   The solution is to identify how much distortion your computer's internal amp creates and avoid it.   The computer source should be at a very LOW level, and an external (and hopefully clean) amplifier is used to make it loud.

With very few exceptions, all computer audio output is a 3.5mm stereo mini-plug.   This connector can be adapted for output to almost any connector.   The problem lies in the basic reliability of the connector.   After months of continous use, the contacts inside the connector lose their spring.   You can avoid connecting and disconnecting the audio plug every day, or you can use a sound device that gives you RCA outputs.   When the connector has converted itself into a mono mini-plug (the tip contact still works, but the ring doesn't) you will have to either "open the system and fix it", or replace the sound card.

More and more motherboard manufacturers are including "DIRECTSOUND ACCELERATED SOUND CHIPS" on their motherboard.   This makes the audio an integrated part of the system.   Avoid integrated audio solutions.   Use a sound card that takes a computer slot.

Yes, there is a significant difference between the DAC on a $29 card and the DAC on a $200 card.   You get what you pay for.   If you have to choose between the $29 card and the integrated audio chip, go with the chip.   In all other cases, use a good sound card.

The way a computer knows how to generate audio at 44.1Khz (that is 44100 cycles per second) is from an internal clock crystal.   The most efficient way for software to adjust pitch is to alter the frequency of playback.   An accurate crystal is required for accurate adjustments, and some crystals don't perform very well at non-standard rates.   Again, use a good sound card.

Laptop Specific Issues

When your internal connector gets worn, it can be a major undertaking to open the laptop case and fix it.   This issue can best be avoided by carefully, and permanently, attaching an adapter to your audio output.   If the connection on the adapter becomes worn, replace the adapter, not the laptop.

Laptop manufacturers are focused on providing audio that is "good enough for a multimedia presentation".   Playing High Quality music demands more then that.   Also, since the ESS chips (and more recently the Crystal Chips) provide an inexpensive and integrated audio solution, PCMCIA audio cards have all but disappeared.   The benefit of portability causes you to lose your options for better quality sound cards.

Saving the $.03 is so important to some developers that they ONLY provide a SPEAKER OUT jack.   The LINE OUT jack gives a better baseline for impedence for driving your external amplifier.   Some SPEAKER OUT jacks are workable, and sometimes you don't have a choice.   When purchasing a laptop for use as an audio source, try to select one with both LINE OUT and SPEAKER OUT jacks.

DirectX Issues

Microsoft pushed the industry in a good direction when they standardized audio drivers.   It allows programmers to focus on writing a program instead of a sound driver support for every seperate brand of sound card.   It also creates a programming problem known as a black box.   Since the hardware manufacturers provide the DirectX driver to support their equipment, you don't know how efficient their code is.   When you ask the sound card to play audio it could be executing hundreds of line of extra code and you can't control it.   Additionally, Microsoft's system creates memory issues that a programmer can't compensate for.   The solution is to avoid the buggy code and stick to big name audio device vendors.   Generally speaking, the big names usually make an effort to have efficient device drivers.

Striving for that extra 1% on the speed benchmarks, watch out for the super accelerated PCI video card.   The video card manufacturers, in their interest of squeezing every last nanosecond out of the benchmark tests, have started with a bad habit.   Using "Bus Mastering" features of the PCI bus, they lock the bus down for everything but video.   Since video is higher priority then audio in the first place, this has a nasty side effect.   The most "common" side effect is that your audio output will literally SLOW DOWN and speed up as it fights for control of the CPU time while the display refreshs.   Until this madness stops, avoid using the super accelerated PCI video cards with selfishly written drivers.

Windows 95/98 Issues

There appears to be a problem with programming a long playlist and leaving the computer to run.   The operating system, with power management enabled, is too dense to realize a program is running.   The hard drive doesn't power down, but the screen might.   Audio playback doesn't stop, but may have a break as memory is paged back and forth to the hard drive.   It is most evident when 30 minutes to 1 hour of music is programmed, then left completely unattended.   "Tickler" routines are included, but since the code isn't designed to keep begging Microsoft for resources, your computer sometimes thinks it can go to sleep.   Disabling APM completely fixes this problem, and touching your keyboard (or moving your mouse) every so often also avoids this issue.   ACPI systems do not have this problem, they are smart enough to know that a program is running.

Microsoft would rather release an update then a working product.   Part of this is because they promise too much, then deliver too little.   Strictly addressing HQ audio on Windows 95, DirectX 3 is superior to DirectX 5.   For Windows 98, DirectX 5 is included, and DirectX 6 is the newer (and still buggy) option.   Specifically speaking, DirectX 5 has a built in "memory leak feature" (I mean problem) associated with streaming multiple buffers into DirectX output.   AMPS avoids this leak as much as possible, but since it is inherent to the operating system(s), it cannot be avoided completely.   The solution is to completely avoid DirectSound output (which doesn't work on slow laptops) or add more RAM.   The TOTAL solution is to switch to Windows NT.

Windows NT Issues

The "business grade" operating system from Microsoft has proven MUCH MORE reliable.   In fact, AMPS was designed on NT then ported to Windows 9x.   Because of the superior multitasking of the NT kernel, and more efficient disk cache manager, the overall CPU usage is lower on NT to accomplish the same task.   Running AMPS on two equal machines, one Windows NT and one Windows 95, the NT interface will feel more responsive and the screen will refresh more smoothly.   Now, the downside.   Windows NT has fewer supported device drivers - so you have fewer hardware options.   Windows NT is more expensive, and the devices it supports are usually the more expensive ones.   Windows NT has a general fear associated with it.   Overcome that fear, and Windows NT is a superior platform for HQ audio.

Cool Edit runs LESS efficiently under NT.   Long batch conversions, for example, are noticeably slower under NT.