Common Issues with Pro Audio from a PC

General Computer Issues

Respect your equipment

A computer is a piece of complex electronics.
Treat is nicely so you don't get a crashed hard drive or cracked screen.

Comparatively Low Quality Internal Amplifier

Most of the hardware market is interested in making cool sound effects for a computer games.   The quality control level may be sufficient for a small amplifier and personal speakers, but it is NOT adequate for professional grade audio.

Solution: Purchase a professional grade internal sound card, or use an external high quality sound device like a USB mixer.

3.5mm Connectors

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.

Integrated Audio

Yes, there is a significant difference between the DAC on the motherboard and the DAC on a $200 sound card.   Use a good sound card, or buy a USB sound device.

Inaccurate Crystal Frequency

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.   Use a good sound card, or buy a USB sound device.

Laptop Specific Issues

60hz Ground hum

When the laptop and the amplifier have a shared ground, you get a nasty amplified hum.   This hum is present any time the amplifier is turned on, even if the computer is not playing audio.   You can confirm the laptop is the source of the hum by unplugging it from power, so it is running on battery only, and the hum goes away.

Solution 1: Run on battery.   Not very practical
Solution 2: Use a ground lift (or use a 3-prong adapter and cut off the ground).   It works, but not recommended.
Solution 3: Use a ground hum eliminator.
Solution 4: Buy a pro-grade USB audio device or USB mixer for your sound.

Low line level, noisy input

Using a laptop's internal sound chip, the output level is a very low level and noisy audio source.   To add insult to injury, it is always coming from a 3.5mm mini-jack.

Solution 1: Use a line-level shifter.
Solution 2: Buy a pro-grade USB audio device or USB mixer for your sound.