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In the Forum: Melquiades Amplifier
In the Thread: To drive the 6C33C...
Post Subject: Ze Zound of Distortion (or not)Posted by Thorsten on: 3/21/2006
Folks,
Before we discuss "high distortion" amplifiers, lets us ask what kind of SPL Romy's system produces.
I don't know, so let me make some eduacated, conservative guesses.
Let us assume his midrange and treble Systems are both 100db/W/m and he listens at 4m distance, or 88db/4m/1W. Having a stereo pair of speakers gives most music enough correlated sound to give at least 4db more SPL.
So, when his amplifiers are cruising at 1W output the SPL will be in the region of 92db at the listening position. The highest averages I measured in the the third row of the Royal Festival Hall during a performance of the Mussorsky/Ravel "Pictures" by a young and energetic russian conductor was around 94db.
If Guy's calculation of 15W @ 15% 2nd HD is right (which it is not on real 6S33's, they are less linear than the 300B but not THAT much) this means at this point Romy's amplifier produces around 4% 2nd HD, much less of all others. In reality I expect something closer to 1% 2nd HD @ 1W for the 6S33.
Is this audible? Perhaps. Patterson et all showed that ears own mechanisms give rise to about 20db MORE 2nd HD at such SPL's. That is merely the ears mechanical system, it should be noted. If we then note the human auditory systems other behaviours we need to ask, is it reasonable to assume that we can hear reliably a "distortion" that matches closely that of the mechanical transducer system in the ear in spectrum but is 20db (or more) BELOW the distortion in the ear?
I for one venture for a clear "not bleedin likely govner!".
As for the Distortion in the EAR834P, it also is rather low when measured with around 10mV @5 cm/S (which gives maximum peaks at 50mV) and certainly very low, when compared to the ears distortion at 92db and that of the LP's mechanical system @ 5cm/S.
Anyway, some food for thought....
Ciao T
Ve cannot all play ze first violin, some of us must sit back here and push vind through ze trombone....Rerurn to Romy the Cat's Site