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ABX distortion test on a real-world tube preamplifier, about 2.7% THD

peufeu

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Hi pma!

I'm going to apply this test to some circuits, so I'd like some advice:

What song gave the best results in terms of ease of hearing distortion for most people who answered?
 

Jimbob54

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I did the tests, might as well share it here.

I was told cumulative results of 30/48 is about 3% to 5% chance of guessing. So, I might be able to sense distortions using my chain a little more often than not?

My chain is laptop USB to Gustard X16 to Topping L30 to AKG K371.

Test results, in order of being taken:

View attachment 143132

View attachment 143133

View attachment 143134

View attachment 143135

Did we say it was or wasnt legitimate to amalgamate results from several runs at an ABX test? I would have thought as A and B are the same files in all test runs it was , but does that still hold if, for example , the equipment used changes between runs?
 

Pdxwayne

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Did we say it was or wasnt legitimate to amalgamate results from several runs at an ABX test? I would have thought as A and B are the same files in all test runs it was , but does that still hold if, for example , the equipment used changes between runs?
No idea about equipment change....But I have to assume should still count as those are still the same two files.
 
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pma

pma

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Did we say it was or wasnt legitimate to amalgamate results from several runs at an ABX test? I would have thought as A and B are the same files in all test runs it was , but does that still hold if, for example , the equipment used changes between runs?

Cumulative results are fine as long as you really count all the trials and not exclude the unsuccessful ones. The equipment should not be changed IMO, as the change of equipment may result in different response to file variations. In any case, the test result will be valid just for you and your test setup. If we wanted to make general conclusions, we would need for everyone to pass the test under the exactly same conditions. I do not think we may have such high ambitions ;).
 
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