"Sound is a mechanical wave that is an oscillation of pressure transmitted through a solid, liquid, or gas, composed of frequencies within the range of hearing."
The act of producing these oscillations is degraded over the distance or medium it must travel to before it is received by the end receiver (in most cases, an eardrum). This is how we perceive sound over distance.
If one wishes delay, suspend or archive the sound for later listening, much effort is required to keep the original sound "signal" as true to the source as possible. The holy-grail is to be able to playback that suspended signal with as least distortion as possible. One could get close to a zero distortion system, but that would be physically impossible.
This project is a comprehensive understanding of signal processing with audio and component level analog electronics. The goal was to develop a line pre-amplifier to accompany a long-playing phonograph machine to attempt the zero distortion playback goal. For the amount remaining distortion in this goal, vacuum tubes are selected over MOSFETs to help manage even order harmonics to produce a more "natural" result with the remaining distortion at hand.
Utilizing performance high-gain triodes in a Mu-Follower 2-stage Full Class-A operating system with a separate power supply caged in a Faraday cage grade copper interior, this arrangement will provide a signal gain of 370 to bring the phonograph cartridge output signal up to an audible level for listening with the least amount of distortion introduced with the quietest sound floor available.
Left and Right channel input signals symmetrically enter the amplifier furthest from the power supply to minimize EMI clouding. High current heater lines are isolated from the High voltage B+ rails and are arranged to have the least amount of electromagnetic coupling with the signal lines.
This completed amplifier functions appropriately. Power Cable is handmade.