The best peanut butter is possibly the one made by hand on mortar and pestle. A marble one does the trick. It takes about 10 minutes for crushing the peanuts until the particles become so small that butter is made. The marble keeps the temperature small like a capacitor reacting to a change in voltage across its terminals. The marble has heat capacity. The capacitor electron storage or charge capacity. The taste and quality sends for tea anything commercial.
Similarly with 1 only transistor Pleiades amplifiers.
They can be hand made in a short time. The collector of the transistor is connected to one terminal of the speaker. The other terminal of the speaker is connected to a fuse for protection and then the fuse to the + battery terminal. The - battery terminal to the transistor emitter. A resistor from collector is connected to base for bias. A coupling capacitor sends the music signal to be amplified to the base. Such an amplifier possibly sends to tea anything commercial. It is possibly the simplest signal amplifying path on the planet. So it sounds like the real thing. As if the instruments are in the room. The quality depends on the quality of the source. Just as the best peanuts and mortar pestle will make the best peanut butter. An efficient full range speaker in a well designed cabinet will assist the miracle. The volume control can be a variable resistor or potentiometer between the capacitor and the base.
See also Pleiades 2N3053 to Philips AD5046N
The DC current passes through the voice coil and this is part of the magical sound. Frequency response is down to 0Hz as there is no output coupling capacitor. A heat sink should normally be used on the transistor to avoid thermal runway.
One of the brilliant videos of a Pleiades amplifier construction:
https://m.youtube.com/watch?v=lrctfMl8qQU
Most of the Pleiades circuits are based on this circuit and are open source.
Both left and right chanels is best sent to the amplifier so that all the music is reproduced. This can normally be done by bridging or connecting the pins together. It does not matter that one only loudspeaker is reproducing (although 2 setups can be made for stereo). Mono reproduction is possibly the best in the planet. For example Madonna's voice of Frozen will come from a point source as if she is inside the room.
Why does the hand made peanut butter sends to the cleaners anything else? Because with the marble mortar and our hand we can keep temperature low. It takes time making it so there is time for oil particles to combine at low temperature and develop a tasty flavor without compromising nutrients by high temperature. We can control exactly the process by feedback from our senses.
Why does a one transistor Pleiades amplifier sends to the cleaners anything else? Because it just has 2 components and therefore the purest and closest signal path to a cable with gain. The amplifier operates in class A meaning electrons are flowing all the time even through the speaker cone voice coil. When we connect the battery a steady current flows through the coil. The cone therefore finds a new equilibrium position while a click sound is heard. A great sound containing infinite frequencies showing the amplifier is capable of a tremendous bandwidth. The bias resistor adjusts the stream of electrons or quiescent current. When the music signal to be amplified enters the transistor base in the form of electrons entering or leaving the base according to the music signal the following happens. When a few electrons enter the base many more leave the collector and enter the speaker voice coil. The cone moves say upwards. When electrons leave the base the collector current decreases much more and the speaker cone moves to the opposite direction. It is all analog. Between 2 values of base current there are infinite values of current. Between 2 corresponding values of collector current there are infinite values of output current. At small signals the amplifier is the most linear on the planet. Like the earth being flat at small walking distances. The quality of reproduction depends a lot at the crossover point. Up and down from the zero equilibrium point. It is where the juice of the music signal is. At high signals the amplifier gracefully peak limits as the transfer curve becomes bent. It may be described as gradually running out of electrons or approaching the power supply 0, + rails. Instantenious peak limiting occurs similar to what happens in nature for large signals or excursions. This increases the loudness to listener's brain while keeping the signal objective output in control [Hamm]. Same behaviour and similar circuitry to the electron tube compressor used at a world class mastering studio in order to make the end product loud to the listener's brain while being able to digitize a peak limited signal so that digital equipment do not run out of 11111111111111..11. The bias resistor can be variable and adjusted for best sound by our ear brain. The exact sweet spot can be found. There is no machine that can do this as it does not have a human brain.
References:
https://www.flickr.com/photos/photoulia/32210168100/
http://euroelectron.blogspot.com/2015/10/pleiades-electra-jfet-headphone.html
Tubes vs Transistor (vs op amps), is there an audible difference? - Russel O. Hamm - JAES
The Pleiades 2N3053 one transistor amplifier connected to the Philips AD5046N loudspeaker - euroelectron
Electronics, a systems approach - Neil Storey
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