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Measuring distortion and modern tools

Iceberg

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In the process of restoring some older equipment I run into a "distortion meter" in the schematics. I see these old tools around, but rather than acquire one of those, does the modern stuff do this for me already and I am just not aware?

If not, what is the current lay of the land in terms of measuring distortion? My goal is to check if a unit matches its distortion specifications after a restoration, so whatever level of resolution that implies is what I am looking for.
 

Balle Clorin

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dc655321

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In the process of restoring some older equipment I run into a "distortion meter" in the schematics. I see these old tools around, but rather than acquire one of those, does the modern stuff do this for me already and I am just not aware?

If not, what is the current lay of the land in terms of measuring distortion? My goal is to check if a unit matches its distortion specifications after a restoration, so whatever level of resolution that implies is what I am looking for.

What equipment are you looking to measure?
 

dc655321

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A typical array of audio components, mainly.

Vagueness makes recommendations difficult. The range of signals under study must be known: voltage/current and bandwidth magnitudes.

DACs? Amps? Vinyl gear?
What is your experience using such measurement equipment and software?
 

Balle Clorin

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I do all of this with the software in my post , add a voltage divider and a pot meter and a high wattage load and amplifiers can be measured too.
Here is how I measure my amplifier
1655143406733.png
 
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I

Iceberg

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Vagueness makes recommendations difficult. The range of signals under study must be known: voltage/current and bandwidth magnitudes.

DACs? Amps? Vinyl gear?
What is your experience using such measurement equipment and software?

It's not intentional, just more or less true. I would be everything from separates like a DAC or a tuner, to pre-amps and amps. Speakers would be interesting, but not critical. I don't get into vinyl.

Yes, I am skilled with most test gear.
 

sergeauckland

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I use my analogue distortion factor meter far more than my digital FFT measuring kit. Two reasons mainly. Firstly, the DFM is calibrated and ready to go without having to boot up, and secondly, it tells me different things to the FFT. A DFM will output the distortion and noise residual, which can be viewed on an oscilloscope for things like crossover distortion and instability at clipping. The FFT on the other hand shows the individual harmonics and IM products, but not the waveform of the residual. I find it much easier to interpret what the DFM tells me than the FFT. I can imagine, however that someone brought up on FFTs would find those easier to interpret. My analogue test meter also measures Wow &Flutter, although again there are digital versions like WFGUI which do a good job. I do use both, and which I use depends on circumstances.

S
 
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