Yahama Receiver

[mpm]

A friend asked me to repair his Circa-1979 Yamaha CR-440 receiver.
Looks like the audio PA is bad. Unfortunately, the IG-02990 module is
no longer available. (At least, I can't justify the $250 minimum
order....)

Can someone confirm an STK-0040 as a viable replacement?

Now the reason for posting in SED: the STK part isn't widely available
either.

Everything in this receiver seems to work except the audio amp.
And actually, it's a really nice unit in great shape!

My question: IF I had to, I suppose I could re-engineer an audio amp
to at least get it functioning again. (My immediate thought is to use
a pair of National Semi "Boomer" series amps...) There's plenty of
room and heat sinking available inside.

Originally, this was a 30-watt unit, but nothing says it has to stay
that way.

Obviously, I would prefer to just swap the final(s) and be done with
it.
But just in case, what would you guys recommend for a no-nonsense, low
parts count "retrofit" for something like this. Thanks. -mpm

 

[D from BC]

A friend asked me to repair his Circa-1979 Yamaha CR-440 receiver.
Looks like the audio PA is bad. Unfortunately, the IG-02990 module is
no longer available. (At least, I can't justify the $250 minimum
order....)

Can someone confirm an STK-0040 as a viable replacement?

Now the reason for posting in SED: the STK part isn't widely available
either.

Everything in this receiver seems to work except the audio amp.
And actually, it's a really nice unit in great shape!

My question: IF I had to, I suppose I could re-engineer an audio amp
to at least get it functioning again. (My immediate thought is to use
a pair of National Semi "Boomer" series amps...) There's plenty of
room and heat sinking available inside.

Originally, this was a 30-watt unit, but nothing says it has to stay
that way.

Obviously, I would prefer to just swap the final(s) and be done with
it.
But just in case, what would you guys recommend for a no-nonsense, low
parts count "retrofit" for something like this. Thanks. -mpm

What do you get when you cross a Yamaha Receiver with funny joke?


....... A Yahma ha ha ha ...

But seriously..
I did something like that years ago..
Sure ...you fix it...it works.. and then your friend doesn't trust the
fix and sells it on Ebay for $50.00.
All your hard work for nothin...


D from BC

 

[Gary Tait]

Everything in this receiver seems to work except the audio amp.
And actually, it's a really nice unit in great shape!

My question: IF I had to, I suppose I could re-engineer an audio amp
to at least get it functioning again. (My immediate thought is to use
a pair of National Semi "Boomer" series amps...) There's plenty of
room and heat sinking available inside.

Is the final on a separate PCB assembly, or all on one? If the former,
it would be quite a bit easier to substitute a different amplifier
design made with available parts.

Originally, this was a 30-watt unit, but nothing says it has to stay
that way.

The power transformer does.

Obviously, I would prefer to just swap the final(s) and be done with
it.
But just in case, what would you guys recommend for a no-nonsense, low
parts count "retrofit" for something like this. Thanks. -mpm

Just pull the amp altogether, mount a set of RCAs on the back for a pre-
out (if it hasn't a pre-out loop already), and use an extenral
amplifier. I did this on an old Monarch 70s stereo (using an older,
rather decent tube amp).