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.

Comments

• rookakoma
• 3 May 2013 at 05:48AM
• WOW! So tight!

• Mark OTL
• 6 May 2013 at 05:25AM
• Simply fastideaous Woodrough!
  A beautifully clean layout.
  
  "This completed amplifier functions appropriately."
  
  This uhm,.. doesn't really tell me how it sounds. What would you compare it to? I love my vinyl and built my own phono stage, a Transcendent Sound unit, and it cleans up some pretty high profile phono's, so I'm curious how your's performs.
  
  Cheers, MarkK.