Getting ready to fix and recap my SX-1010

[Rock&Roll]

Well, it's been almost a month now that I've had my SX-1010 up and running.

After setting the bias & dc offset, I proceeded to get a few good weeks of enjoyable listening out of the unit. Everything seemed OK. However, it seems the victory parade is coming to halt.

Something this receiver has never done for me, tripping the protection relay, happened 3 times in a very short period just now. However this repetition has not resumed since. This is only the most recent symptom.

More prolonged, the left channel will occasionally voice a very short hiss that sounds very much like someone loudly wispering "pssssst" to get your attention. It took me a while to confirm that this was a receiver problem and not just a faulty source signal or loose connection.

Out of the many transistors on the amp boards, I only replaced Q5 and Q6. So I'm questioning if the remainder may be where the problem emits.

I have found no way to force the reproduction of these symptoms. So I'm curious if there's somewhere better to start looking

 

[EchoWars]

You might have to replace a few transistors on the protect board. The hiss may be a real battle to track down. Start off by pulling the pre-to-main jumpers and seeing if it disappears.

 

[markthefixer]

You could shotgun the control amp be replacing the 2sa725's with:
512-KSA992FBU (ln)to-92 ecb 120v .05a .5w 100mhz 150-800hfe $0.05 ea

and the 2sc1312's with:
512-KSC1845UBU (ln)to-92 ecb 120v .05a .5w 100mhz 150-800hfe $0.05 ea


These basically are all the transistors in the preamp that are NOT in the tuner or the phono amp....

You don't mention if the source you are using is the tuner, phono or aux or if it occurs in all of them.

The possibility does exist that it's a power problem.