Can 'ARTA' measure tube electronics?

[Cousin Billy]

Hello all

I will be measuring my diy speakers. First I would like to test my equipment. I would like to do this as a reference. I would hate for a peak or dip to be non speaker related.

Will Arta allow these measurements, and what type of soundcard or special cable do I need?.

[ashok]

If you mean frequency response and distortion , yes of course.
You can measure some other things also.
However you will be adviced to use some form of protection at the input of the sound card in case you inadvertently apply high voltage dc or ac to the sound card input. If you do that ,it will result in blue smoke from your sound card and you know "that" cannot be put back !

I know , it happened to me . I was very careful , but a slipped probe for a fraction of a second was enough. So a buffer or protection circuit ( dc blocker cap , voltage divider with zener clamping ) is probably mandatory for absolute safety.

[Cousin Billy]

More specifically.

Which are the better (more accurate) soundcards?.

What type of connection do I use?.

My Atma-Sphere pre-amp uses balanced output, do I need to make up a special cable?.

[Pan]

Best depends on several things..

USB?
Firewire?
PCI?


If you are going to use it for measurements obviosuly the things you are going to measure determines the performance of teh audiointerface. You need the noise and distortion of the interface to be lower by a good margin.

For PCI cards Echo Audio's Mia is good value and Lynx2 the best.
There are other alternative as well.

For USB I strongly recommend E-MU 0202USB or 0404USB.

For Firewire, Echo Audio Audiofire2/4 is very good.

edit: sorry, I didn't read carefully enough. I see that you want to measure speakers which means that you would need a mic preamp, then E-MU 0404USB and Audiofire4 is my advice.

Audifire4 is extremly good and can easily replace a CDP in a top notch stereo rig.


/Peter

[Svein_B]

"Best soundcard" is probably not required. Start by using what you have.
I have successfully used several different notebooks with satsifactory performance.

A simple loopback test with a 3,5mm plug in both ends will show the basic performance of your soundcard, in particular noise-floor and LF / HF roll-off.

For basic amp measuremnet, using ATRA or some of the other alternatives, you need a level adaptation from the amp output to your soundcard input. For measuring power amps a 1/10 voltage divider is suitable for connection to soundcard line input. For connection to mic input something like 1/500 is preferred. Se illustration below.

Measuring a preamp with balanced output should ideally use a soundcard with balanced input.

SveinB.

[Cousin Billy]

Thank you Svein_B

Digigram has both an interface cable UAX220-MIC (Balanced I/O), and a Balanced sound card with phantom powered microphone pre-amplifier VX222HR-MIC.

Anyone have any comments?.