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5% THD to .000 THD SOUND

I was searching the amplifiers available and noticed quite a big difference in THD specs from model to model. Example.. One of the best amplifiers Kondo Audio Note $150k Kagura has 5% THD and by reviewers definition sounds like an amazing amplifier. Now compare $ 30k  Devialet with the lowest 0.000% THD on the planet. Both at the opposite end of design yet both sound amazing.. according to reviewers, I havn t heard either. SN/R  133 by Devialet and a lot less by Kagura. I realize an amplifiers sound can t be based by Specs alone.  If the specifications are not that important to the sound, why list them? They must be a way of determining sound, quality, and system synergy of an amplifier? A whole lot of amplifiers purchased on the net haven t been heard before and I believe the decision to purchase is made by reviewers point of view, specifications and word of mouth of other owners and buyers pocket book. By looking at specs of Devialet and NOT knowing the prices of Kagura and Devialet I would of gone with the Devialet just based on specs alone for the impression of it being a  great sounding amplifier.  Ive read other discussions on forum and cant quite get a handle on why BOTH amplifiers sound great. I thought High THD was a bad thing..
derrickengineer
charles1dad's avatar
charles1dad
10,250 posts
 
I’ll give proper credit to Mr.William Bruce  Cameron. Different messenger, same impactful message.
Charles,
geoffkait's avatar
geoffkait
23,365 posts
 
By the way, the quote you might possibly be looking for is,

"If you measure a certain audio parameter and it measures poorly and the device under test sounds bad you're probably measuring the wrong thing." - anonymous audiophile

charles1dad's avatar
charles1dad
10,250 posts
 
That makes the point as well.
almarg's avatar
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almarg
9,670 posts
 
Bwaslo 8-1-2016 1:36 am edt
The percent distortion spec, as usually given, should be read for the POWER level that produces it (i.e., to indicate what the manufacturer assumes is the maximum power the amp might do).
This is an excellent point, among other excellent points in Bwaslo's post.  In looking further at the descriptions of various Kondo amplifiers I see that **all** of the SET and parallel SET models listed at their site (Kagura, Ongaku, Souga), and also the Gakuon II which is not listed as a current model, are indicated as having 5% THD at their specified maximum power ratings.  Presumably if their max power ratings had been specified less aggressively (i.e., somewhat lower), the specified THD would have been significantly lower.

Interestingly, though, their Overture integrated amp, which is a push-pull EL34 design, has its max power spec based on 1% THD.  Just guessing, but perhaps their thinking is that differences in how THD is distributed among the various harmonics when the two kinds of designs (DHT SET vs. push-pull pentode) are operated near their limits would result in say 2% THD in the push-pull EL34 design being subjectively more objectionable than 5% in the DHT SET designs.

On the other hand, though, as Atmasphere has pointed out on numerous occasions, for best sonics a SET should not be called upon to provide more than a small fraction of its rated power, as in contrast to push-pull designs the distortion produced by a SET becomes vanishingly small at low power levels.

All things considered, for an application requiring just a small fraction of the Kagura's rated power I'll retract my previous statement about ruling it out from consideration on the basis of the 5% number.  Although I would feel more comfortable in doing so if comprehensive measurements (such as John Atkinson provides in Stereophile) were available.

Best regards,
-- Al
derrickengineer OP
36 posts
 
Great insight into the realm of audio equipment and sound. Thanks. 
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