Electronics repair (older kenwood amp)

[brutal]

Yamaha CA-810

Picked it up on Ebay a few years back. Had a buzzing noise, so cleaned everything with electronics cleaner. Noise went away.

The amp is set up with a Mac Mini run through a DAC to the amp. The sub woofer is plugged in to one side of the "pre out-main in". I'm getting a "revolving" static sound that seems to build when everything is on. If I unplug the amp the noise goes away for a while. If I unplug the sub the noise is diminished (same thing if I restart the Mac Mini). I've run two different laptops on this system with no problems, so not sure if the Mini is the issue.

Talked to Dr. Dan yesterday and dropping the amp off on Sat. There are some other issues I want him to look at. I normally wouldn't bother but I like sound of the amp.

CA-810 integrated is a nice unit. It's worth putting a little $ into it to keep it running. Yamaha has often been call, "A wire with gain." they truly are "Natural Sound." Yes, I'm a huge fanboy.

I don't recall off the top of my head if there are any in that model, but there's a specific transistor that was commonly used in many products of that era that are know to go noisy. SC458 "outhouse" cause it's rectangular with a sloped top and looks like an outhouse. Obviously it could be lots of other things, including dried out electrolytics, particularly in the PS sections... Also poor ground connections lead to lots of weird things. Hell, without a polarized plug, even switching that around can sometimes fix ground loop/noise issues.

Anyone cleaning switch contacts should be using only Caig DeoXit products. Magic sauce in there. Even then, there are special formulas without harmful solvents if the switch internals have some plastics. Read all about them here, http://store.caig.com/s.nl/sc.2/category.188/.f , but then buy wherever is cheaper.

Dr Dan should be able to get that thing squared away for you.

I don't have one here, but do have the CA-1000, CA-1010 and CA-2010. :-)

There's a reason jerrymrc gave me my current handle. He's another member here I met at a local AK GTG.

[jerrymrc]

CA-810 integrated is a nice unit. It's worth putting a little $ into it to keep it running. Yamaha has often been call, "A wire with gain." they truly are "Natural Sound." Yes, I'm a huge fanboy.

I don't recall off the top of my head if there are any in that model, but there's a specific transistor that was commonly used in many products of that era that are know to go noisy. SC458 "outhouse" cause it's rectangular with a sloped top and looks like an outhouse. Obviously it could be lots of other things, including dried out electrolytics, particularly in the PS sections... Also poor ground connections lead to lots of weird things. Hell, without a polarized plug, even switching that around can sometimes fix ground loop/noise issues.

Anyone cleaning switch contacts should be using only Caig DeoXit products. Magic sauce in there. Even then, there are special formulas without harmful solvents if the switch internals have some plastics. Read all about them here, http://store.caig.com/s.nl/sc.2/category.188/.f , but then buy wherever is cheaper.

Dr Dan should be able to get that thing squared away for you.

I don't have one here, but do have the CA-1000, CA-1010 and CA-2010. :-)

There's a reason jerrymrc gave me my current handle. He's another member here I met at a local AK GTG.

I know nothing. I do remember the early days @ AK. I still drop in from time to time. Brought my switchable Yamaha stuff with me to Europe. I did recap a few items that had just been sitting. I will say that once recapped many items were in spec right off the bat.

[theGinsue]

As soon as I can find the manuals for the components I'll be putting up my old Kenwood rack system up for sale. Damned thing is in great condition even thought it's circa 1989, but it's been sitting unused in my basement since about 1995 (no speakers). I'm hoping that $100 will be low enough for an audiophile to be interested in it. They sure don't make good steroes these days like they used to.

[brutal]

As soon as I can find the manuals for the components I'll be putting up my old Kenwood rack system up for sale. Damned thing is in great condition even thought it's circa 1989, but it's been sitting unused in my basement since about 1995 (no speakers). I'm hoping that $100 will be low enough for an audiophile to be interested in it. They sure don't make good steroes these days like they used to.

If it's 70's silver gear and each piece weighs more than 25 lbs, it's probably something worth much much more than you think. Sometimes this old stuff is literally worth it's weight.

Even much of the early 80's stuff, after they went black is great gear. The late to early 90's maybe not so much, all depends on the make/model. If it was top of the line (TOTL) at the time, it's usually a keeper or has some value. If it's BPC (Black Plastic Crap), it's probably Goodwill fodder.

[SideShow Bob]

If you can get the schematics and parts list with numbers, the only real challenge is if the parts are still available.
Most times, it is the final power amp transistors or SIM’s that blow or burn up in the older tuner/amps.
I used to repair them as a hobby a long time ago when the parts were plentiful. But I no longer have access to all the equipment to do the circuit tracing to confirm which component that has actually gone bad.

[Ah Pook]

@Brutal

Dr. Dan is the man!! Took the amp to him and he cleaned it, first thing. Of course there was no problem.

Got it home and still had the same odd buzz. DD took another look. We came to the solution that it was an exterior problem.

Excellent service from a great guy.

Edit: DD was impressed with the CA-810 and that it was still working so well.