I have used ECG and others in the past and most of the time they work
but when they do not you can waste a lot of time finding out why.
Mostly this is an audio amp using matched NPN and PNP circuits the
closer I follow that the longer the amp will last and with smaller DC
offset, this amp only has bias adj. and I am only repairing one channel
at present so also going for as close to that as possiable and I do not
stock many general replacement types and do stock many japanise,
american and european transistors in matched pairs for this reason.
Actually I would have ordered the NTE if they had matched pairs "MCP"
after the number.
Jeff