Solved. I am now reasonably confident it is used for both temp compensation and clamps the input to the next stage at one BE voltage drop above and below GND at thermal shutdown. Justin On 5 September 2016 at 17:36, Justin Richards wrote: > in previous post > > "..and considering ..". > > should read > > "...and I am considering ..." > > > Is it possible that they are temperature compensated biasing. Still not > 100% happy as does not explain how the thermal shutdown works. > > > Justin > > On 5 September 2016 at 15:42, Justin Richards > wrote: > >> I have confirmed with both the schematic and the actual amp that the >> collectors are tied to the bases and both transistors bases are tied to >> each other,. >> >> It remains a mystery and considering that they are used in some way to >> provide diode volt drops that match another pair of the same transistors >> that are closely bonded on the same heat sink. >> >> I would like to make the manufacturers schematic available but I have >> been asked not to do so. >> >> Justin >> >> On 5 September 2016 at 11:08, RussellMc wrote: >> >>> Are collectors really joined to bases, as shown? >>> -- >>> http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive >>> View/change your membership options at >>> http://mailman.mit.edu/mailman/listinfo/piclist >>> >> >> > --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .