First thing that I mention, what a beautiful amp, outside and inside, on the top side, hardly wires. I know the feeling when someone brings in the same electronics that fails. Your heartbeat goes up and you get kinda sweaty. If this happens here, I do the repair for free, inc transport costs. Even it's not my fault. Like you said, older equipment can fail in many ways. That's why I love to do projects in development. Like at the very moment I'm creating a faderstart with everything in it (light tree, relays, temperature control in PWM for 2 small fans, and programming map files), for radio use. That's pretty much my specialty. But learned again from this video, so thank you very much.
I hear you, Gunther. My heart just sank when he told me it died. I insisted on paying shipping, but he shipped it anyway. An I don't plan to charge him either. I think he's understanding due to the fact that he owns a vintage Corvette.
You understand. I understand. Thankfully the owner understands. But most folks point the finger at you as the last person to have their hands in whatever it is you repaired. And to make this particular episode worse is that the symptoms were identical in each failure.
@@Silent-Lucidity Like so many things, it depends where you look. If you find a good audio forum, you'll find guys like me, who do this work for the mental stimulation and to preserve this gear for others.
That Sansui is as old as I am, and when I wake up in the morning I wonder is my left knee going to give me hell today, where did my 20/20 vision go, why does my right ankle click for the first few minutes when I get out of bed, these units are old but like us they are worth keeping around even if we both need a little extra care. My AU-517 and TU-717 get used daily!
The parts with me scratching my head or tearing my hair out are on the cutting room floor. 😝 But seriously, I try to explain the thought process and steps you take to isolate the problem(s). And theories as to what the issue might be, even if later proven wrong. Because you have to start somewhere.
Ray , one other comment . Low ft outputs can cause too much phase shift making the global feedback approach positive feedback. Early Crown USA amplifiers used lots of global feedback and changes made by the output transistor manufacturers created some stability issues when the output devices deviated from the originals.
Good points, Herb. It's getting harder all the time to find acceptable substitutes for transistors, especially those older high Ft outputs. We do the best we can!
I would consider that to be wear and tear plus transit fatigue. I've tested many amps before even taking the lid off to find its dead when it was supposed to be noise or a channel down, ring the customer up to say its dead and 80% of the time they say what have You done to it! Well I haven't even taken the lid off yet SIR! transportation is a killer to old worn kit. I think those old 80's and 90's paxolin pcbs warping was the usual culprit
In this case transit isn't an issue, as the owner picked it up himself and drove it back home. At the age this stuff is there are going to be more age related issues cropping up. But yeah, shipping is just brutal, and no doubt getting worse all the time since the shippers beat their employees for more and more productivity.
After thinking about it, I believe the RU-vid videos helped. The owner was able to see his unit "under the knife", so to speak. It adds a certain amount of transparency to the process. Even if he doesn't hear the director say "Cut! Call in the stunt technician." 😁
@@cwradio4571 Well, it's just a theory. But I've had comments from folks who's gear I've worked on that indicated the videos helped them understand the issues found.
@@raygianelli3612 well I will use this in some deals I do from now on. I don’t post videos but I think we will video the problem from now on an allow people to see the process an problem.
Whenever you hear the “ever since you” comment, the customer is trying to get you take ownership of the problem in the hopes you will not charge them for the repair.
Ahora mismo estoy en la misma situación. Se reparó cambiándole los condensadores, black flags, etc. A los 20 días dejó de funcionar y ahora está en el punto de partida, en el taller.
