Now I can see that no problem , I did look at the schematic you posted but because the detail is so small on that schematic when you blow it up it's just blur . This partial caption has far better resolution .actually would it be possible to get a shot of just the main board so its values can also be seen , it's just that one schematic that's the problem everything else on the other pages translates well . thanks so much Boky
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Understand that ALL chemicals do damage. Some additionally gum things up or cause dust to stick more easily (and that holds moisture).
What causes the noise? Not the resistive element (carbon track normally). The metallic slip ring inside is what gets noisy. It oxidizes, gets a sulfate coating or both. So ... knowing this what would you do?
Cleaners attack lubricants. That means the protective coating on carbon tracks and the sleeve bearing the shaft turns in. Ever see a sloppy control? Too much cleaner, too often. It wore out. Removing lubricants causes damage over time. Once you notice it - too late (and it can take years). New control time. I will use fine oil in the front of the bushing in a control to extend it's life if the customer allows enough labour time. I do this all the time on my own equipment, old tube radio, test equipment or stereo. Some newer controls are plastic (shaft) and use damping fluid. It gets thick over time. For those you take them apart carefully - they are easy to damage and this is labour intensive.
The same holds true of many aspects of servicing. When I apprenticed, I was taught the correct way to do things and cleaning controls (and why / how) was one of them.
What causes the noise? Not the resistive element (carbon track normally). The metallic slip ring inside is what gets noisy. It oxidizes, gets a sulfate coating or both. So ... knowing this what would you do?
- Don't clean controls that don't need it.
- Operate the controls occasionally as they are designed to clean when used - within reason.
- Use as little cleaning solution as possible, directed to the centre of the control or in the switch.
- The best is a zero residue cleaner with nothing else in it.
Cleaners attack lubricants. That means the protective coating on carbon tracks and the sleeve bearing the shaft turns in. Ever see a sloppy control? Too much cleaner, too often. It wore out. Removing lubricants causes damage over time. Once you notice it - too late (and it can take years). New control time. I will use fine oil in the front of the bushing in a control to extend it's life if the customer allows enough labour time. I do this all the time on my own equipment, old tube radio, test equipment or stereo. Some newer controls are plastic (shaft) and use damping fluid. It gets thick over time. For those you take them apart carefully - they are easy to damage and this is labour intensive.
The same holds true of many aspects of servicing. When I apprenticed, I was taught the correct way to do things and cleaning controls (and why / how) was one of them.
No, I'll buy that some chemicals do damage, and cleaning without re-lubrication does damage, but ALL chemicals? No. In fact sealing in a nitrogen atmosphere would be a chemical that definitely does good by excluding oxygen, possibly the harshest chemical already.
That brings back memories... from a very long time ago... I agree 100% with everything you said.
Hi Tony,
lol!
No. I haven't got enough time to do videos. Not only that, but it isn't possible to show people everything. There's always more and it depends on what the situation is and what you remember. Trying to pack 50 years of experience (including time I wasn't paid to learn) into even a one year course just isn't going to happen. Now think about trying to cram that into videos. People tend to learn a little, then blame their teacher for their errors 'cause they simply don't know enough (or forgot).
That's the problem. A really good technician does a million things in their head without thinking about it. This allows us to take calculated short cuts while keeping an eye out for problems. To an outside observer it looks effortless sometimes. And if a person doesn't have a lot of training and experience, they think it's easy.
What they say is true. The more you know, the more you know you don't know.
I would consider teaching at the college or university level. First pre-req course - common sense 101, 201 and 301.
lol!
No. I haven't got enough time to do videos. Not only that, but it isn't possible to show people everything. There's always more and it depends on what the situation is and what you remember. Trying to pack 50 years of experience (including time I wasn't paid to learn) into even a one year course just isn't going to happen. Now think about trying to cram that into videos. People tend to learn a little, then blame their teacher for their errors 'cause they simply don't know enough (or forgot).
That's the problem. A really good technician does a million things in their head without thinking about it. This allows us to take calculated short cuts while keeping an eye out for problems. To an outside observer it looks effortless sometimes. And if a person doesn't have a lot of training and experience, they think it's easy.
What they say is true. The more you know, the more you know you don't know.
I would consider teaching at the college or university level. First pre-req course - common sense 101, 201 and 301.
A while back I purchased a lv103 cheap because it also had problems , after looking it over found the transistors on the preamp had bad solder joints , re flowed them and a few other suspect joints on the main board and it came back to fully functional . It did also have a tick in the treble control but after cleaning it everything seems normal (same cleaner as posted above ) .. Now that I have found people with far greater experience in electronics I just wanted to backtrack a bit and make sure I was using the correct product .. I did notice the transistors on the preamp of the 103 looked to be getting quite hot likely the reason the solder failed so I added heat sinks , let me know if that is a bad idea .. other then that the lv103 looks to be a perfect example of a very well kept low use amp , boards are completely spotless and it sounds great ... Thanks for the tips guys I am learning every time I'm on this site .. cheers Roger
Hi Roger,
Hot parts indicate one of two things on average. A fault (regulators failed and voltages too high), or poor design. This is common on HK as they erroneously believe that extremely high bandwidth sounds better. So they upped the current everywhere and parts run too hot as a result. Of course if the parts run warm to start with, high ambient temperatures will push the running temperature up even higher.
Hot parts indicate one of two things on average. A fault (regulators failed and voltages too high), or poor design. This is common on HK as they erroneously believe that extremely high bandwidth sounds better. So they upped the current everywhere and parts run too hot as a result. Of course if the parts run warm to start with, high ambient temperatures will push the running temperature up even higher.