In a Yamaha TRS MS02 for a Yamaha Tyros 2 keyboard
3 ch , 19 pin hybrid chip. I cannot find the pinning . A 27MB SM out there
has full component level schema for the Tyros but not the powered speaker
add on . Strange use of screened signal lead carying the 2ch input signals,
to take 1ch back to the keyboard, separate lead for the other ch and woofer
in the box. I'm particularly after the standby or mute pin.
The STK433-240E is a different pinning, this one no suffix , ie not "A"
either. Cold tracing so maybe erroneous
-power p2
+power p3
ch A, p4+5 o/p
ch B, p6+7 op
gnd p9+10
p11 an input, assumed , as capacitor feed
p15 an i/p same C
p17 an i/p, same C
p18+19 chC, op
leaving 1,8,12,13,14,16 unplaced so far, LV supplies ? , FB ? etc

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

wrote in message ...
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



A useful tabulation in that pdf, thanks . I'd wondered why there were what
looked
like disc ceramics at the 3 inputs, in fact for feedback, and had not
noticed the 3x load sensing W/W dropper 0.22Rs were connected between the
output pin pairings