Has anyone seen Rush pairs used this way?

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#22
Hi Ian,
in the past years, i have designed those two output stages, that i think are similiar to your schemes. More simplified, direct coupled and without caps in the signal path. I not have built them at this time, but that in fig.1 seems more promising in simulation.
What you think about?🙂🙂
 

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#23
Bigun said:
he may have looked at something similar and discarded it along the way... ‘theres nothing new under the sun’ or so I keep reading

I simulated a symmetrical Rush some years back, but I lost interest in symmetrical designs for front end although my TGM7, which is symmetrical but not a Rush, is not too shoddy

Hugh gave you a hint already but you missed it because you are very set on your current design... he said “dominant H2”, something that lends a character that you don’t usually get with a well-matched symmetrical front end. Afterall, if we seek only lowest possible distortion we fail to understand the art of sound and merely repeat the goals of many.
Click to expand...

Dominant even order harmonics is not anything new "under the sun". Many designers knew it from J. Hiraga's book. I follower Audoiphile his magazine from the first issue in late 70's, the story of dominant even harmonics started in 60's by the Japanese after analyzing the Marantz 8b distortion can be seen in Hiraga's book. The second order is 20db if I do remember higher than the third. After this , designers following reciepes adopted this audio astrology . No one asks the question , Why Sydny Smith the designer of 8b did use a dirty IF/detector tube and using it at very low voltage/current in very nonlinear region. He made the same in model 9 but with less nonlinear tube. To remind that S. Smith before hand , for precedent famous brand , used a nonlinear tube before the volume to generate even order harmonics at constant ratio.
Personally I consider this, chaptalizing., adding sugar in low quality wine . If you need such a dirty element to introduce even order harmonics , the best I tried is the Russian 6N1p running in transconductance. it can generate over 60db second to third harmonic. It is possible to add up to 14% pure even orders. Installing such an element before the volume, it can vinylze the digital sound.
About my amp , what do you know about its harmonic distribution. The single ended Rush , yes it is mirrored, but have you seen a perfect mirror? The outputs ,are they really complimentary to cancel out all their even orders?

Hayk.
 
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