Digital Audio Signal Generator

[prairiemystic]

Just wondering what people are using (besides their ears) to test their gear.

Silicon Chip Magazine, March/April 2010 has a Digital Audio Signal Generator project by Nicholas Vinen. Sine, square, triangle, sawtooth, mixed, pulse sweep etc. and uses a PIC micro (dsPIC 33FJ64-GP802 at 40MHz) portable with LCD display. It has S/PDIF, TOSLINK digital and analog outputs (0.06% THD). 1Hz-24kHz at 48kHz sample rate, 1Hz-48kHz at 96kHz sample rate.
I think they used it on their Sept./Nov. 2009 "High-Quality DAC" project, getting 0.0006% THD+N at 1kHz overall. Distortion less than 0.006% up to 20kHz or 0.005% @ 96kHz.

I was thinking of building one or maybe PC soundcard-based tones (digital) would do? The kit is about $140 US at Altronics

[dangus]

A soundcard makes sense, or there's test CDs. You can generate signals with software like Cool Edit and burn your own. Use an MP3 player if it supports digital out and lossless files.

But it depends on what you need it for. Sometimes there's no substitute for an oscillator that tunes with a knob, like if you're hunting for a resonance. And for some test purposes, you need an uninterrupted signal, so that narrows it down to dedicated generator or PC-based.

[Zero One]

If you have an iPhone there are a number of applications to generate audio signals, sweeps, fixed tones, polarity testers, and db meters for very little money. For example you can probably get the whole lot for less than $10.00

I have several of these but as yet have not got around to trying them out on the system.

Worth looking at.

[jameslover]

A full range of digital audio test signals for maintenance, repair and calibration of professional audio equipment is generated. User test signals may be stored as uncompressed WAV-files in the DR2 memory.