PSYCHOACOUSTICS
 
 

    On this page we discuss the psychology of music and sound. The focus is in how we hear things differently and how we perceive the effects of different amplifier technologies and techniques. There are many aspects of psychoacoustics ranging from pitch perception to the illusions created by combined tones and sequences. But we will only discuss the aspects related to audio and perception of reproduction. These include the perception of frequency response and tonal balance, imaging, and some talk of sound localization.

    There are at the extremes two opinions with regards amplifiers. One is the engineers point of view, and one is the hobbyists point of view. Both have valid arguments and both are off their rocker on other points. I will try to be an arbiter between the two extremes. Somewhere in the middle, but on its own extreme point of view is the purist. I am closer to the purist philosophy, but I like a little color too!

    Before I continue I would like to express a sentiment that I had read in several places with regards textbook accuracy. The general idea is that most textbooks are written more to maintain consistency rather than accuracy or truth. In other words, if five textbooks on the subject of the color of the sky say that it is blue-green, then it is accepted as fact, even if when looking outside we see it as blue-grey, merely because so many textbooks can't be wrong, can they? Well, Yes they can. If you look at the rear of your favorite textbooks you will see that there are tons of reference materials that the writer may or may not have actually read and is copying from (the ideas, not the words). So, if he is reading erroneous texts, he too will write an erroneous text and will be unaware of it. So the errors continue to propagate.

    I make many quotes from texts and trust that they are accurate mainly because 1) I have actually tried the experiments for myself and see that they are correct and 2) I trust that once I have tested the accuracy for myself that the rest of what the writer has written they have tested themselves also. However, where my tests seem to contradict text and the established theories, I will speculate a theory and attempt to expound with discovered data and phenomena and experiments that seem to support the theory.

THE DESIRED SOUND

    The straight wire with gain thought is kind of impractical. If this were a perfect stray-fieldless universe the straight wire will introduce no self inductance or capacitance. It will have no resistance. It will be perfect. However, to have gain, we need to introduce a force of some kind. Newton expressed this as F=MA. In order for acceleration to occur, a force must act on the mass. In this case the acceleration is the amplitude, the mass is the original signal, and the force is the amplification device. If the force comes with its own characteristics, then the output signal will not ever be the same as the original. There will be interaction between the force and the signal. Given the fact that the wire also has imperfections acting on and impeding the original signal, we have a signal that only vaguely resembles the original. Some of these foreign additions can be quite pleasing and add some character to the original signal, but some can get quite annoying and harsh.

    What we can hope for is a scenario where the original signal that goes through the wire with its impediments to signal flow can be acted upon by a force that actually compensates for the losses.

    This is where the fun begins. Which tubes sound better? Which rectifier tube sounds better? Which capacitor sounds better? Which wire sounds better? Do I use silver solder? How about star wiring? Point to point as opposed to circuit trace PCB's? Tubes or transistors, why? If amplifiers specifications are equal, they should sound the same, but they don't. Why?

    These are just a handful of the questions and suggestions by hobbyists answered by hobbyists and engineers and psychologists (psychoacousticians) alike that can either have a basis in factual science or not. Here we will discuss the different tricks and tweaks and why it sounds to us as being or not an improvement.
 
 
 
       Psychology and Sound. Why we hear what we hear.
      Wire. How much better does monster cable sound?
      Capacitors. Believe the hype!
      Resistors. Can they make a difference?
      Tubes. The real crux of the matter.
      Transformers. What's the deal?
      Power Supplies. The current scoop.
      Transistors. They aren't really that bad, are they?
      Speakers. Will they ever be perfect?