N_Cook wrote:
3 ch , 19 pin hybrid chip. I cannot find the pinning .

How about http://www.bdent.com/v/vspfiles/down...K433-270-E.pdf and
look at page 6, which has a pinout for an "STK433-240A-E" (3 channel,
class AB, 40 W). It seems to match what you've traced:

Sanyo N_Cook What I think it means
1 -PRE Preamp negative supply?
2 -VCC -power Main negative supply
3 +VCC +power Main positive supply
4 OUT/CH1+ Ch A out Channel 1 output +
5 OUT/CH1- Ch A out Channel 1 output -
6 OUT/CH2+ Ch B out Channel 2 output +
7 OUT/CH2- Ch B out Channel 2 output -
8 +PRE Preamp positive supply?
9 SUB.GND Gnd Substrate ground (connect to ground)
10 GND Gnd Ground
11 IN/CH1 input Channel 1 input
12 NF/CH1 Channel 1 negative feedback?
13 STAND-BY Standby
14 NV/CH2 Channel 2 negative feedback?
15 IN/CH2 input Channel 2 input
16 IN/CH3 Channel 3 input
17 NF/CH3 input Channel 3 negative feedback?
18 OUT/CH3+ Ch C out Channel 3 output +
19 OUT/CH3- Ch C out Channel 3 output -

I'm particularly after the standby or mute pin.

Elsewhere in the datasheet, it looks like you tie pin 13 to ground (or
less than +0.6 V) for standby, and connect it to something between +2.5
and +5.5 V for operation.

Matt Roberds