Hi Jim;

thanks for the reply to the moan. Today I had another go at the mods to the
BK - with the same result.
Working into a 4.7 Ohm resistor load, and driven into saturation, the
waveform across the load is of a non-fuzzy, triangular - going - on -
sawtooth, profile with a crossover pimple and a p -p value of only 30 V. and
the current drawn by the o/p devices is pretty well balanced at about 400mA
each leg at Vcc so  SOMETHING is limiting the drive.
I left the 39 Ohm resistors in cct and went back from 1k2 to the 4k7
originals, whereupon the o/p figures returned to normal.

This afternoon I installed four Vero pins to allow rapid changes of the
source resistors but it will be a day or two before I am able to fiddle
about and see what happens with different values.

Thanks ffor the help.

Ian