Hi all,

I would be interested in any experience the group has with PC based
audio equipment testing. It seems to me that with readily available PC
soundcards now having up to 24 bit 96kHz sampling, and capable of
producing tones up to 48 kHz or so, a variety of testing could be
implemented fairly easily, with appropriate software. I'm thinking of
oscilloscopes, audio signal generators, spectrum analysers, distortion
analysers etc. If anybody has any experience of paticular
software/hardware I'd be very interested in your comments.

many thanks,

Pete.

I have used Winscope, AnalFreq (a spectrum analyser suited for amp work)
and there's a few Python based audio oscillator/multi tool toolkits. All
freeware.

My s/c is a Yamaha DS-XG50, capable of a 96 KHz max sample rate in forced
mono.

--
Gregg
*Perhaps it's useful, even if it can't be SPICE'd*
Visit the GeeK Zone - http://geek.scorpiorising.ca

Hi,

I am using a software from this site http://www.audiotester.de/ The
software can do spectrum analysis and also make the audiocard work as a
low distorsion signal generator. Depending on the audio card performance
the sofware can handle up to 48kHz which is very useful for amplifier
testing. Dynamic range depends on the noise level of the audiocard, in one
of my PCs the built in audiocard permits about 110 dB dynamic range which
is probabaly more then enough for most users, on the other hand I have
another PC where the noise level from the main board disturbs the
measurements and limit the dynamic range to about 85dB so performance
depends on the audiocard. The software also includes a oscilloscope but I
dont think this is so useful due to the limited BW so I use a 40MHz
ordinary analogue scope.

This is one of the lowest cost options I have found and it works very
well, a demoversion can be downloaded free of charge but stops
automatically after a few minutes of use so you need to restart the
program.

Regards Hans

Pete67 wrote:

Hi all,

I would be interested in any experience the group has with PC based
audio equipment testing. It seems to me that with readily available PC
soundcards now having up to 24 bit 96kHz sampling, and capable of
producing tones up to 48 kHz or so, a variety of testing could be
implemented fairly easily, with appropriate software. I'm thinking of
oscilloscopes, audio signal generators, spectrum analysers, distortion
analysers etc. If anybody has any experience of paticular
software/hardware I'd be very interested in your comments.

many thanks,

Pete.

"Pete67" wrote in message
om...
Hi all,

I would be interested in any experience the group has with PC based
audio equipment testing. It seems to me that with readily available PC
soundcards now having up to 24 bit 96kHz sampling, and capable of
producing tones up to 48 kHz or so, a variety of testing could be
implemented fairly easily, with appropriate software. I'm thinking of
oscilloscopes, audio signal generators, spectrum analysers, distortion
analysers etc. If anybody has any experience of paticular
software/hardware I'd be very interested in your comments.


Also see http://audio.rightmark.org/ .

You can just loop the amp with dummy load and attenuator along with the
sound card.

.

You can just loop the amp with dummy load and attenuator along with the
sound card.




That dummy load needs to be more than just a power resistor. It should
look like a speaker to the amp. Possibly an inductance in series or
parallel
(or some combination) with a resistor. Or a speaker located in another
room (assuming no neighbors).

"Robert Casey" wrote in message
...

You can just loop the amp with dummy load and attenuator along with the
sound card.

That dummy load needs to be more than just a power resistor. It should
look like a speaker to the amp. Possibly an inductance in series or
parallel
(or some combination) with a resistor. Or a speaker located in another
room (assuming no neighbors).

Agreed.

You didn't look at the URL in my other post, did you?

;-)

Here it is, again.

http://www.pcavtech.com/pwramp/macrot-5000VZ/index.htm

This test shows the results of both resistive and reactive load testing.

The loudspeaker simulator I recommend is described in detail in the lower
part of this page:

http://www.pcavtech.com/pwramp/index.htm

"Robert Casey" wrote in message
...

You can just loop the amp with dummy load and attenuator along with the
sound card.


That dummy load needs to be more than just a power resistor. It should
look like a speaker to the amp.


** But which speaker ? There is a huge variation in impedance
characteristics.


Possibly an inductance in series or parallel (or some combination) with a
resistor.


** THD and response testing is always done with resistive loads - so
specs can be fairly compared with other amps. A reactive load condition can
be simulated with a additional inductor or capacitor in series with the
resistor load - the frequency where the impedance of the additional
element equals the resistor value is usually the one most likely to provoke
a reaction from any VI limiting that may be installed.


Or a speaker located in another room (assuming no neighbors).


** Speakers are a very often non-linear loads so will exaggerate THD figures
if the amp has only a modest damping factor ( like tube amps do) .

As well, speakers are easily damaged by continuous high power levels -
so not a practical option for amp performance testing.



................ Phil

This is where the whole Krueger/Pinkerton axis wobbles into
absurdity.

Which speaker should the load look like, and in which room?

The simple reproductionist argues that, in order to achieve the
necessary linearity throughout the chain from the original sound
source to my room, each link must itself be linear. When he says
that no speaker (and presumably no microphone) gets close to hi-fi,
Arny consigns his whole edifice to obscurity. It is meaningless in
the real world, and its central tenet cannot be tested.

According to a recent discussion on microphone placement, if Arny
had his way I would end up sitting under the piano.

Just a token resistance...I know Arny has heard it all before, and
is obviously committed to his cause come hell or high water.

I think we are into complimentary transforms here. Mess about until
it sounds right, then maybe measure for fun.

cheers, Ian




"Robert Casey" wrote in message
...


.

You can just loop the amp with dummy load and attenuator along
with the
sound card.




That dummy load needs to be more than just a power resistor. It
should
look like a speaker to the amp. Possibly an inductance in series
or
parallel
(or some combination) with a resistor. Or a speaker located in
another
room (assuming no neighbors).