Gareth Magennis wrote in message
...


"N_Cook" wrote in message
...
Output ok up to 1 watt out then output clips both sides of sine. All
valves
test fine for gain and internal leakage. Signal is fine up to the wiper
of
the treble, ie before the splitter/driver, that signal stays sine well
into
clipping of the output. Changing the splitter is the same. Running at
clipping and dropping the HT via variac makes no difference , changing
output bias makes no difference to the clipping. The splitter valve
cathodes
measure about 34V and the grids about 23V at point of clipping. All the
surrounding Rs measure ok. Output Tx primary measures 139R red to white.
Capacitor problem? amp was subjected to a knock that dropped the output
of
the rectifier valve , since changed, a session before this problem
emerged.





Can't really follow that.

If you pull the phase splitter, are its grids getting an undistorted
signal
measured at the empty socket?

Similarly, if you pull the output valves and put back the phase splitter,
are they getting a good grid signal?



Gareth.




I may as well try removing the output valves and trying on 80 percent mains
or so ,and check their cathode signals, but looks more and more like a turn
or few , shorted turns in the Tx