huangyong 0 Report post Posted March 8, 2004 (edited) hello guys. after doing some experiments, there is still lots of left over components and experiment board, so, i design this amp, which use most of them, heyhe... "recycle". i don't have a camera, so can't really post my amp here, sorry, but i attach my schematic here, just to share. in this humble amp, i put in a a input stage amplifier with a gain of 2, the input of amp is directly input from source.it is class-a biased also. opamp:NJM4556. sorry for the flaws, it was connected to -12V not +10v. and the output of input satge is fed in to a Grado RA-1 like amp, with Solen 5uF Cap, and high value resistors. with a gain of around 3.2. opamp:NJM4556 and i also provide a ground channel for it. the board was my Poor man PPA experiment board ( same circuit as PPA, except i use opamp buffer to replace the BUF634) . I have tried it with opa134 as amp, and NJM4556 as buffer, but the bass slam too hard, too strong. finally, i found a op27, put it in , and it just sound nice. frankly, i don't expect this amp to sound good at first, i just built it like playing Lego. Haha... but the final result was good, the sound is neutral (just nice to me, non fatigue), detail, sound stage is unexpectingly wonderful, and one thing to share after listening for hours is that it sound like a cross-fed amp, but it is not!! hope to find a camera and put the pics here. Thanks for viewing. Edited March 8, 2004 by huangyong Share this post Link to post Share on other sites
tropicalrips 0 Report post Posted March 8, 2004 i also like "recycle" amps a lot of my own amp are also built from left-over parts hope to see the actual amp soon Share this post Link to post Share on other sites
huangyong 0 Report post Posted March 22, 2004 (edited) julery help me to take this pic.thanx. the amp is case-less. Edited March 22, 2004 by huangyong Share this post Link to post Share on other sites
hacknet 0 Report post Posted March 22, 2004 its said that the cheap njm opamps are more warm and laid back sounding, only problem is they lack detail hope you enjoy Share this post Link to post Share on other sites
tropicalrips 0 Report post Posted March 22, 2004 can't see the pic huangyong Share this post Link to post Share on other sites
lekguan 0 Report post Posted March 22, 2004 http://img37.photobucket.com/albums/v113/j.../Huangyong2.jpg Share this post Link to post Share on other sites
jasonhanjk 0 Report post Posted March 22, 2004 Ahh, the tupperware. This remind me of something. Share this post Link to post Share on other sites