Trio KA80 thinking of buying, but sound comes out starts distorting then nothing

[bazza31]

Hi everyone, so I've done some research and believe the output transistors are bad. Is this correct and if so will it be an easy fix

 

[as_audio]

Time to ask an expert in your area.

 

[latala]

I would not bother the output stages are a specialist module which will not be available nice enough in its time and an easy repair if only the parts were available

 

[Boydk]

https://www.diyaudio.com/community/threads/blast-from-the-past-kenwood-ka-80.291492/

 

[bazza31]

Thanks, I've read that thread, but from my description what do you think the problem is. I was only guessing about the output transistors

 

[jacques antoine]

If the output transistors were broken, there would be no sound at any moment and certainly not at startup.
Sounds more like a PSU problem, like bad caps.

 

[bazza31]

Sorry for the delayed response, ok your thoughts are bad caps....right will that be a relatively easy repair? I see If i can download the schematic

 

[Boydk]

Thanks, I've read that thread, but from my description what do you think the problem is. I was only guessing about the output transistors

My guess is the same as the rest of most in here.
Defective output module (STK-0060).
Since these are EOL, and 99,8% of what´s out there are chinese fakes, that never live up to their spec´s,
I would definitely stay as far away as possible from a project like that, unless you´re an experienced technician with
years and years of experience.

 

[bazza31]

Git it, appolydgys for quality

 

[bazza31]

Last few

 

[bazza31]

My guess is the same as the rest of most in here.
Defective output module (STK-0060).
Since these are EOL, and 99,8% of what´s out there are chinese fakes, that never live up to their spec´s,

Ok...if by chance a KA80 amplifier was in good working order how would one try to prevent the output module from defecting or any other component in that matter?

I've read its a very good/amazing amplifier with outstanding dynamics.
Would like to own one and enjoy.

 

[Boydk]

Ok...if by chance a KA80 amplifier was in good working order how would one try to prevent the output module from defecting or any other component in that matter?

You would probaly need some input from someone far more experienced than me, to improve
reliability og something, japanese engineers already put together.
Biggest issue is, that they "chose" to use Sanyo´s STK circuits for outputs.
Unfortunately, these later proved to be unreliable. Wouldn´t know how to go about replacing that without
losing some of the sound characteristics, others praise to high regards.

 

[bazza31]

Ok so odds being that if one performs well naw I could be that it's one of the good ones. After so many years treated respectfully and not abused I think I will still be looking forward to owning a good working order Trio ka80.