This is a page of design notes for my "big" amp, a stereo OddBlock? Octal rendition. See][project page for design details.

2020-11-10 Replaced the JJ KT77's with KT120s. Still at "63mA" bias setting. R channel is running more like 70mA and not too stable. Balance is good, just overall current not too stable. Also, the LM317HVK get pretty hot.

Power estimate- 45V @ 0.18A would be 8.1W on the LM317.

Thinking of some upgrades:

  • Replace heatsink with maybe these: HS531-ND (1.8" sq).
  • Add a testpoint on "Out" pin of LM317 to check operation
  • Possibly add a small fan
Last modified 21 months ago Last modified on Nov 12, 2020, 10:51:46 AM