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The Headphone Amplifiers Page


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  HiFi Headphone amp, Front  
  Portable Headphone amp, Front  
  I have built and rebuilt several headphone amplifiers, including amplifiers to go with my main home hifi setup, and portable headphone amplifiers that I use to listen to MP3's at work, or to improve the sound of an MP3 player.  
  The first amplifier I built was for my home setup that I put in the old DAC case. It was an IC-based design with an input stage, volume control, gain stage, and OPA2134/BUF634 output stage, described here. Around the same time I built a simpler, CMoy-style portable amplifier with two OPA2134 stages, as described here. 
  After using the OPA2134/BUF634 amplifiers for a while, I began to covet something better. I was seduced by the reviews of the Gilmore "Dynalo" discrete amplifier on the Headwize site, so I built one of those, described here and put it in the old DAC case in place of the OPA2134/BUF634 board. I then took the old OPA2134/BUF634 circuit board and modified it to fit in a new portable case, added an AC source for a better power supply, to create a second portable amplifier, as described here. 
  Finally, I ended up messing around with the OPA2134/BUF634 circuit board so much that I busted the leads on one of the BUF634s, so I decided to rebuild the thing and do a proper job, as described here. 
  A later project was a truly portable, CMoy headphone amplifier that I crammed into an Altoids box, as described here. I later built a second one as well, in a different colored box. 
  My latest project was a portable, discrete, JLH-variant, as described here that I use to listen to music at work (replacing the OPA2134/BUF634 portable amplifier). The JLH amplifier sounds incredible, nearly as good as the big Gilmore amplifier. 
  In summary, here are the various pages about my headphone amplifiers: 
  For my Home System:    
  For my Portable System: