On Mon, 13 Mar 2017 02:26:56 -0600, wrote:

I've been looking into buying an Audio Generator (Sine and Square Wave).
I mainly want this to run thru an amplifier to listen to the frequency
repsonse of the amp and speakers.
Here is the ebay URL.
(...)
http://tinyurl.com/h5celuc

That DDS generator only goes up to 65KHz, does not have a built in
frequency sweep feature, and does not have a sawtooth output or built
in detector suitable for displaying a frequency sweep on an
oscilloscope. To sweep an audio amplifier with a DDS, you will need a
sine wave generator feature, and an up/down counter or frequency
modulator to sweep the frequency range.

First look at a real function generator. Next, build a checklist of
the features you need. Then, go shopping using the feature list.
You're doing this backwards.

Note: You can use a PC sound card as a swept audio source and
function generator:
http://www.daqarta.com/dw_gen.htm
http://www.instructables.com/id/PC-Sound-Card-Signal-Generator-Interface/?ALLSTEPS
etc...

Most of the PC based oscilloscope and spectrum analyzer programs have
built in generators. I use Visual Analyzer:
http://www.sillanumsoft.org/prod01.htm
and Spectrum Lab:
http://www.qsl.net/dl4yhf/spectra1.html
Both have built in generator functions, including two tones for
intermodulation measurements.

This scope program has a tolerable white/pink noise generator.
https://www.zeitnitz.eu/scope_en

Hint: Buy a higher resolution USB sound card that will do 24 bit 96
KHz, 192 KHz, or if you have money to spend, 384 KHz clock rate. The
common 44/48KHz devices don't make very good test instruments.
External USB is better because sound chips built into a PC or laptop
pickup noise from everywhere.

However, I must admit that $15 test equipment is lots of fun to play
with. I have LRC meters, function generators, DDS RF generators,
return loss bridges, noise generators, etc most of which cost about
$15.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558