====== references ======
  *[[http://www.headphoneamp.co.kr/bbs/zboard.php?id=diy_sijosae&page=1&sn1=&divpage=1&sn=off&ss=on&sc=on&keyword=6922&select_arrange=headnum&desc=asc&no=249|MHHA v3.0a (Multi-Hybrid Headphone Amp]] - 24V단전원, 관 12AU7
  *[[http://www.headphoneamp.co.kr/bbs/zboard.php?id=diy_member_new&page=2&sn1=&divpage=1&sn=off&ss=on&sc=on&keyword=SHHA&select_arrange=headnum&desc=asc&no=1644|진공관 입문작, Sijosae-YAHA.. (종합)]] by 전일도 님
  *[[http://blog.naver.com/skaghrms/40053659551|진공관 파워앰프 기초강좌]] from 달마 님 블로그
  *[[http://www.tubeamp.net/technote6/board.php?board=kkkddara3&PHPSESSID=8a480b2c9d6252e0c9221906af04a8db|왕초보따라하기]] from 한진동 
  *[[http://www.7l1wqg.com/jisaku/lm2577/LM2577-ADJ24.pdf|LM2577 12 to 24]]

====== shops ======
  *[[http://www.audiozang.com/|오디오짱]]
  *[[http://www.audioparts.co.kr/|오디오파츠]]