I'm trying to repair an Onkyo surround sound amplifier with a blown STK
422-730.
I wouldn't normally take this on, but it is for a friend who is not very
well, or very wealthy.

Well first off, I can't even find a datasheet for this particular STK, let
alone find an STK 422-730 I could buy.

(STK's from china don't count as they will be fake and I need to get this
working ASAP)
The original is a Sanyo package like this, but this is not a Sanyo part:
http://www.ebay.co.uk/itm/1PC-STK442...AOSwXXxZW3r W


So I have been looking at substitutes.
There are a whole range of 2 channel STK's with 14 pins, of various
amplifier powers.
Are all these compatible? If I get something close will it just plug in and
play?


There's a whole load of other much cheaper older package STK442-XXX modules
available, eg:
http://www.ebay.co.uk/itm/Hybrid-IC-...AOSw53NY~io e

Not being able to find the datasheet means I don't even know the power, but
that is not as important as getting this amp into some semblance of making
sounds again.

Might it be worth taking a punt on one of these cheap older packages not
from China?



Cheers,


Gareth.

Dammit, my typo.

It's a STK 442-730.



Gareth.

On 31/07/2017 20:45, Gareth Magennis wrote:

I'm trying to repair an Onkyo surround sound amplifier with a blown STK
422-730.
I wouldn't normally take this on, but it is for a friend who is not very
well, or very wealthy.

Well first off, I can't even find a datasheet for this particular STK,
let alone find an STK 422-730 I could buy.

(STK's from china don't count as they will be fake and I need to get
this working ASAP)
The original is a Sanyo package like this, but this is not a Sanyo part:
http://www.ebay.co.uk/itm/1PC-STK442...AOSwXXxZW3r W



So I have been looking at substitutes.
There are a whole range of 2 channel STK's with 14 pins, of various
amplifier powers.
Are all these compatible? If I get something close will it just plug in
and play?


There's a whole load of other much cheaper older package STK442-XXX
modules available, eg:
http://www.ebay.co.uk/itm/Hybrid-IC-...AOSw53NY~io e


Not being able to find the datasheet means I don't even know the power,
but that is not as important as getting this amp into some semblance of
making sounds again.

Might it be worth taking a punt on one of these cheap older packages not
from China?



Cheers,


Gareth.


I long ago stopped trying to find exact replacements, settling on 1, or
2 for stereo, easy to find TDA7293. A bit of time working out the pinout
of the original . The only hiccup has been , sometimes the mute line
needs a simple inverter transistor in line with it/them. None bounced
back , is all I cansay on reliability

On Monday, July 31, 2017 at 3:45:44 PM UTC-4, Gareth Magennis wrote:


(STK's from china don't count as they will be fake and I need to get this
working ASAP)



I was screaming about counterfeit semis back in the 1980s when everyone thought I was full of crap.


But.. not all semis out of China are fakes. I'll bet that if you buy that STK on ebay, it will fix the stereo and it will last.

"John-Del" wrote in message
...
On Monday, July 31, 2017 at 3:45:44 PM UTC-4, Gareth Magennis wrote:


(STK's from china don't count as they will be fake and I need to get this
working ASAP)



I was screaming about counterfeit semis back in the 1980s when everyone
thought I was full of crap.


But.. not all semis out of China are fakes. I'll bet that if you buy that
STK on ebay, it will fix the stereo and it will last.



Not only that but you can easily get your money back if it is fake.

How much power is this thing ? If it is not too high you can just rewire it to use a pair of LM3886 or something. They are not bad chips. I did that a year or two ago on a unit that used an SVI chip, which is an STK but just considered fancy.

On Saturday, August 5, 2017 at 2:51:53 PM UTC-4, Gareth Magennis wrote:

Well, having ordered a STK 442-120 and expecting it to arrive in 2 days max
as usual, it didn't.
Wasn't even dispatched until friday, I assume half the staff are probably
on holiday. Most unusual.

Anyway I decided to have a look at using a pair of LM's/TDA's or whatever,
only to find a new STK 442-130 in my TDA drawer I didn't know I had.
I must have ordered two some time in the distant past and gave myself a
spare.



Here's something you probably don't realize: if you didn't order the -120 the -130 would have remained hidden. I don't understand the physics of it but it's best to just admit this stuff happens (plus, you'll feel better)..